Intercooler System Tech

General Tech 

Coyote Tech 

3v Tech 

Intercooler System Tech

Intercooler System Requirements Tech

Settle in, this is not a quick read.

Let’s start with a story/situation.

You’re doing some mods to your car that are significant enough to need an entire fuel system. 800hp on e85 for example. You contact your favorite vendor/parts source and this is how the conversation goes:

You - “What size fuel injectors and pumps do I need to feed the motor 800rwhp of e85.”

Vendor – “I have these really nice looking injectors with red anodizing and a pump also anodized red that should work”.”

You – “What is the fuel flow of the injectors and pump and how much is needed to feed this motor enough e85?”

Vendor – “Trust me my man. I have sold a ton of these to my customers”. (I just saw a vendor state that to someone just days before writing this)

You - “I’m looking for technical specifications, not sales speak. How do I know if you sold those people stuff that doesn’t work for them? What are the technical specifications and what are my needs?”

Vendor- “I don’t know”. (good luck actually getting someone to say this)

What would you think about the above conversation when you’re looking for concrete data on what you need for a fuel system?  We’re going to guess something along the lines of:

- How can you not know this?

- How am I going to spend thousands of dollars and not know if it’s what I need or not?

- Does this guy care at all that he may be selling me the wrong stuff?

- Is making the sale all he cares about?

- Or, all of the above.

You would find the above conversation completely unacceptable and go somewhere else, wouldn’t you?

Why is it then that everyone buys intercooler system components exactly as laid out above? How is that remotely acceptable? Does that seem reasonable to you? We don’t think it does. It seems ridiculous actually.

We know why vendors sell intercooler system components based on no data. There isn’t any. Which is ridiculous too. Well, that’s no longer the case.

We have been testing air to water (A2W) intercooler systems (IC) for positive displacement (PD) superchargers for about 10yrs now. We have collected a massive amount of data. We will wager that we have more testing/data than everyone else in the business combined. No one is doing the sort of testing we do. Not even stuff as simple and critical as tracking water temps throughout the intercooler system. Or testing water speed. If you don’t have those two things, you don’t have any useful data. And there are a lot more things to test than that.

We now have enough data to put together specifications for what is needed to set up a A2W IC system to get the job at hand done. We’re hoping that now that the data is out there the buying public will start demanding it like they would if they were buying a fuel system. People should be getting what works. Not what a vendor wants to sell them.

Let’s get to this…….

What is not in this article?

- This article is only about what sort of specifications you need to accomplish “X”. It is not a in depth article on IC systems theory. That’s for another day.

- We do not address ice chest in this article. Two reasons. One, it would be hard to inject that into what you’re going to read below. It would get confusing. It’s a completely different and focused on a set of completely different circumstances. Two, we feel that unless the car in question is going to the drag strip A LOT it’s not a good idea to run an ice chest. Fantastic IAT’s can be achieved with just a heat exchanger. More often than not better than cars with ice chests. Ice is not a silver bullet. It doesn’t make that big of a difference. If the car has only water in the tank (most cars, most of the time) it’s not doing anything measurable for keeping IAT’s down. And your lugging around almost 100lb extra weight. We like ice chests in the right situations (race cars). Most people/cars are not in those situations. At some point there will be an article on ice chests.

 Goals

You can’t solve for a “problem” without knowing your goals. We’ll use the fuel system situation above as an example. You knew what your goal was. You needed to supply enough fuel to make 800rwhp. A pretty simple and straightforward goal. If we were to ask you what is your IC system goal, we suspect most people can’t answer it accurately. We have found MOST people don’t even know they have a problem.

Another situation/analogy for you……

Let’s say you buy a new 2020 Mustang GT. Over the first week you have it you notice that every time you go wide open throttle for more than 4-8 seconds the engine gets hot and the computer pulls ignition timing knocking 75-100hp out of it to keep it safe. You……would……go……..bonkers! You would be all over the internet trying to figure out why, is it normal, etc. You find out it is normal. You take the car back to the dealer and tell them to fix it. They can’t because nothing is “wrong”. That’s just how the car is. You start lemon law proceedings because it’s ridiculous that that is how the car works (or in this case, doesn’t). No one would accept the above situation.

The above situation is EXCATLY what you get with just about every blower kit out of the box. Why is this tolerated? It’s tolerated because most people don’t know what their inlet air temps (IAT) are, and if they do, they don’t know what they should be. There are no red flashing lights going off on the dash when the IAT’s get too high and the car starts pulling timing/power. If there were, the inside of most cars would look like a rave. And you would be fuming about the problem

The goal seems pretty obvious right? The IAT’s should never get hot enough to pull timing/power. The performance loss is enough to get angry about. You pay about $40/hp when modding. How does it feel to have wasted $3000-4000 every time the IAT’s get hot? Not good. And lastly, if you’re anything like us it just pisses you off that the system wasn’t engineered correctly. Hell, they’re not even in the same ZIP code as “engineered correctly”.

Specifications Disclaimer

Let’s start with what blower kits come with out of the box (these numbers will mean something to you soon).

- 5-7gpm (gallons per minute) of water flow

- A heat exchanger with a core volume between 250 and 500cu in

What do you need you ask? That’s a complex answer that has to be qualified:

-The first qualification is that you want your IC system to perform as well as your stock engine cooling system. We can’t see setting the bar any lower than that. Someone is sure to argue it though.

-The second is that there are a zillion variables when it comes to cooling systems. In every single situation someone can say “Yeah, but…..(enter arguing on the internet here)”. We’re going to have to be ok with there not being any laser focused answers for everything in this article because there will always be a variable someone can toss into the ring to “break” the solution. That said, what we have for requirements are really really tight. If you put what is currently out there for data/requirements and our requirements on a scale of 0-100 the data available before this was posted was a 10 on that scale. Our data/requirements is a 95.

-For the most part this data is “non-transferable”. How this data was collected is a huge factor. For example, how was water speed tested? What sort of system was the speed tested in? What gauge/meter was used? What coolers were in that system? What voltage were the pumps run at? There can be a HUGE swing in the numbers due to testing variability. And then there is the lie factor. We have absolutely seen bold faced lies when it comes to water speed. We’ve seen claimed water speeds that are over double what is possible. They either didn’t test correctly, they have bad measuring tools, they’re lying, or all of those combined.

-We test all of the pumps, line sizes, etc on a test rig we built just for that job. It replicates the engine compartment, the placement of each component, the hose lengths used, etc. We use the same heat exchanger and intercooler for every test (fitting size is adjustable). It’s as close as you can get to replicating real life without spending OEM level money testing. It is very easy to get different results by testing a different way. Remove the heat exchanger from the loop, you will get a higher water speed. Shorten the hoses and you will get a higher water speed. Feed the pump more voltage, you will get a higher water speed. Even changing where the intercooler is located vertically will change the water speed. Something as small as changing a few fittings from straight to 90deg will change the water speed. We test all of out stuff with the same variables every time. We even went as far as to set up a flow meter in our S550 to see if the actual in car water speed was the same as it was on the test rig with the same combo. It was really close. Within 1.25gpm at 28gpm of water flow. We can’t ask for more accuracy than that.

We’re going to tell what the system requirements are. We want to be absolutely sure that you understand that the figures we are giving you can’t be compared to other sources of data. If the testing was done differently the data won’t correlate.

Specifications

You will see two different specifications in the chart below. Bulletproof and Pretty Darn Good. Pretty scientific huh?

Bulletproof – This is a performance level equal with the cars OEM engine cooling system. What most would consider the goal and the lowest you want to set the bar.

Pretty Darn Good - This one is a bit harder to define. Most of the time you will have no temp issues. But if you let’s say want to do three back to back to back 12sec wide open throttle runs you may get a little hot and drop a few HP toward the end. Or if it’s absolutely blazing hot out you may be limited to one 12sec wide open throttle run before you need to give it a short break to recover. And if it’s blazing hot out, you have been sitting in stop and go traffic or just driving at a slow pace stopping at a lot of lights on surface streets you may drop a few HP at the end of a single 12sec run. Pretty darn good is pretty darn good and way, way better than what 98% of blown cars have going for them. This may be enough to keep a majority of people happy.

Look out for the modifiers at the bottom of the chart

In an effort to keep the chart down to a reasonable size we didn’t chart everything out. We put some variables in at the bottom that you can apply as you see fit. The composite barrier being one important modifier. Everything in the chart assumes that there is one in play. Because that is how our manifolds come…..and it’s our chart. If you don’t have one of our manifolds or you haven’t purchased some composite barriers just add 4gpm to every line on the chart.

Remember the specifications above relating to how blower kits are spec’d out by the manufacturers? If not, here they are again.

- 5-7gpm (gallons per minute) of water flow

- A heat exchanger with a core volume between 250 and 500cu in

Now compare them to the requirements below. Yeah, they’re a LONG way away. They don’t even get close to “Pretty darn good”. Why are the kits spec’d out like they are you ask?

-Money

-The customer base is not demanding better quality

-They don’t know how to do it correctly

-IAT issues are easy to get around on the dyno

-If done correctly they’re pretty easy to mask at the drag strip too

The last two items represent the vast majority of advertising.

The Chart

ic system requirements -- if you want us to send you the spreadsheet, please contact us

 

How Do I Achieve The Specifications I Need?

Depending on what blower you have, you may not be able to. Welcome to the dirty little secret of the forced induction industry.

You can take a look at out intercooler systems we have available for your car/blower combo and see what is possible. There are multiple kits with different pump/heat exchanger/line size combinations for each car/blower. What’s you’re looking at is the most ideal combos for that particular blower based on available pump/heat exchanger/line size combinations. Or, you can keep going below and see what we have for water pump/line size/heat exchanger data/measurements. Which is a lot.

 

Water Pump/Line Size Data

Below you will find links to specific cars/blower combinations. If you do not see your car/blower combination choose whatever car you have paired with a Roush blower. The Roush’s are very “down the middle”. Yours is probably very close to the same.

If you have a GT500 it doesn’t matter what blower you have, your manifold/intercooler is probably OEM. The Kenne Bell Bigun IC has the same numbers as the OEM IC does. If you have a “Flow Modded” IC those numbers are in there. If you have a custom manifold with big IC ports you can look at the flow data for our manifolds (3v or Coyote). Just match you port size up. Our manifolds run all of the port sizes.

The line size specifications assumes the entire system except the intercooler (IC sizes is in different column) is at least that size. In other words, no smaller restrictions.

2007-2014 GT500

-2007-2014 GT500

2005-2010 GT

 -Department Of Boost GT450 GenI

-Department Of Boost GT450 GenII

-Roush/Whipple

-Saleen/Eforce/Magnuson

-Kenne Bell

 2011-2014 Mustang GT

-Department Of Boost GT550

-2.3L Roush/VMP/Whipple

-2.9L Whipple Gen4

-3.0L Whipple Gen5

-Kenne Bell

2015-2017 Mustang GT

-Department Of Boost GT550

-Roush/VMP

-2.9L Whipple Gen4

-3.0L Whipple Gen5

-Kenne Bell

2018-2020 Mustang GT

-3.0L Whipple Gen5

-VMP Odin

Heat Exchanger Size Specifications

Here are heat exchanger size specifications for almost every one available.

-S197

-S550

 

Intercooler Water Pump Flow Charts

Water Pump/Line Size Data

Below you will find links to specific cars/blower combinations. If you do not see your car/blower combination choose whatever car you have paired with a Roush blower. The Roush’s are very “down the middle”. Yours is probably very close to the same.

If you have a GT500 it doesn’t matter what blower you have, your manifold/intercooler is probably OEM. The Kenne Bell Bigun IC has the same numbers as the OEM IC does. If you have a “Flow Modded” IC those numbers are in there. If you have a custom manifold with big IC ports you can look at the flow data for our manifolds (3v or Coyote). Just match you port size up. Our manifolds run all of the port sizes.

The line size specifications assumes the entire system except the intercooler (IC sizes is in different column) is at least that size. In other words, no smaller restrictions.

2007-2014 GT500

-2007-2014 GT500

2005-2010 GT

 -Department Of Boost GT450 GenI

-Department Of Boost GT450 GenII

-Roush/Whipple

-Saleen/Eforce/Magnuson

-Kenne Bell

 2011-2014 Mustang GT

-Department Of Boost GT550

-2.3L Roush/VMP/Whipple

-2.9L Whipple Gen4

-3.0L Whipple Gen5

-Kenne Bell

2015-2017 Mustang GT

-Department Of Boost GT550

-Roush/VMP

-2.9L Whipple Gen4

-3.0L Whipple Gen5

-Kenne Bell

2018-2020 Mustang GT

-3.0L Whipple Gen5

-VMP Odin

S197 Heat Exchanger Available Sizes/Tech

Heat Exchanger Size - Tech Information

S197 Tech -- Heat Exchanger Sizes 1

We have been testing heat exchangers for 10+ years now. As far as we know we are the only ones that test heat exchangers by tracking water temp in/out. Which is the ONLY way to accurately test a heat exchangers performance. There are too many very large variables in play to use intake air temperatures as a gauge of heat exchanger performance.

In one car alone, we had seven different heat exchanger configurations. Five in another. Three in two more cars. Some of them off the shelf units, some of them completely custom. We’ve tested up to 1500cu in of core volume.

After 10+ years of testing one thing rings true 95% of the time. The bigger the heat exchanger, the better it works. There is an argument that a bigger “face” will make up for lack of core volume a little though. If you have two 800cu in units your comparing but one has more “face”, go with that one.

Passes:

As far as “passes” goes we have also not seen any evidence to suggest that more passes are better. But there are situations where more passes hurts cooling because they choke down system wide water flow/speed due to the core not being large enough to run that many passes. The results are all over the place. The short version is don’t bet the farm on how many passes a heat exchanger has. It probably doesn’t matter.

Core Design:

We have yet to see any truth to a small XYZ whammie jammie heat exchanger with its NASA designed space age core with XXX better heat transfer out performing a bigger unit. It’s possible that’s a thing. We find it unlikely anyone will ever do accurate testing to determine if it’s true though. The rig you would need to build to do that sort of testing would cost a fortune. And a lot of time. There is no way to accurately measure them on a car. That said, we have a window of core specifications that have worked well for us and we stay in that window. We’re certainly not saying that the core design doesn’t matter.

------------
Hose Size:

The hose/fitting size on a heat exchanger can make or break how much water you can flow. Almost all heat exchangers have .75” fittings. It’s very difficult if not impossible to achieve adequate water flow to control inlet air temps with fittings/ a system size that small. As a rough outline this is how much water speed changes with system-wide size change. Here are some specs based on using a Stewart E2512A water pump. Keep in mind most superchargers do not have an intercooler with bigger fittings than .625”. Some as small as .55”. So, don’t expect most systems with .75” hose to flow the .75” number below:

1.25” – 28gpm

1” – 21gpm

.75” – 13gpm

------------

Measuring core sizing:

This is the only way we have found to measure them consistently.

Core size, side to side (width), is measured not including tanks, just the core.

Core size, top to bottom (height) is measured from the outside (top side, bottom side) of the last “tubes” open to airflow.

Core thickness is the thickness of the core minus any headers, footers, etc.

Most advertising you see for heat exchangers contains sizing based on overall dimensions. That is not the “working size” of the heat exchanger. The core size is.

Thick/Tight Cores Are A Problem:

Through testing we have learned that once cores get thicker than 2.625” they’re too thick to efficiently pass air though them. As an extreme example we have tested a 2.65” core vs a 3.125” core. The 3.125” core had half the airflow of the 2.65”. So yes, core size/volume is very important. But only if that volume is attained without making it too thick.

-------------------------------------------------

Specifications:

 

Department Of Boost Titanic Triple - Gold

Width: 24.875”
Height: 15.6125”
Thickness : 2.6465”
Hose/line size: .75” – 1.25” (adjustable)

Frontal Area: 388.36 sq in
Core Volume: 1027.79 cu in
--------------------------------

Department Of Boost Super Single - Red

Width: 24”
Height: 12.375”
Thickness : 2.5”
Hose/line size: .75” – 1.00” (adjustable)

Frontal Area: 297 sq in
Core Volume: 742.5 cu in
--------------------------------

 

13’ GT500 Stock Heat Exchanger - Purple

Width: 25”
Height: 10.875”
Thickness : 3.125”****
Hose/line size: .75”

Frontal Area: 271.875 sq in
Core Volume: 849.60 cu in

****There is a shortcoming with this HE that betrays its dimensions. It is very, very thick and has a very dense core, which makes it resistant to airflow. Thinner/taller units with a freer flowing core will shed more heat even if they have a lower core volume (not too low though). This is a pretty good unit. And they can be had, if you can find them, for very little money comparatively though. We rate our Super Single much better than this unit despite its smaller core volume. The Super Single will pass a lot more air through the core. And the Super Single can be run with up to a 1” line which is the only way to get stout water flow numbers.
--------------------------------

 

C&R Heavy Duty/Shelby Extreme - Orange

Width: 24”
Height: 12.4225”
Thickness : 1.75”
Hose/line size: .75”

Frontal Area: 298.14 sq in
Core Volume: 521.75 cu in

--------------------------------

VMP Triple (GenII) – Dark Blue

Width: 24”
Height: 12.25”
Thickness : 1.5”
Hose/line size: 1.0”

Frontal Area: 294 sq in
Core Volume: 441 cu in

--------------------------------

VMP Triple (GenI) – Dark Blue

Width: 24”
Height: 12.25”
Thickness : 1.5”
Hose/line size: .75”

Frontal Area: 294 sq in
Core Volume: 441 cu in

--------------------------------

Saleen Extreme - Pink

Width: 32”
Height: 7”
Thickness : 2.125”
Hose/line size: .75”

Frontal Area: 224 sq in
Core Volume: 476 cu in

****There is a shortcoming with this HE. It’s very wide which causes airflow inefficiency at its edges. It’s performance is not quite as good as it’s core volume would suggest.

--------------------------------

C&R Standard/Shelby Comp - Green

Width: 24”
Height: 9.6125”
Thickness : 1.75”
Hose/line size: .75”

Frontal Area: 230.7 sq in
Core Volume: 403.72 cu in

--------------------------------

LFP - Yellow

Width: 21.75”
Height: 8.125”
Thickness : 2.375”
Hose/line size: .75”

Frontal Area: 176.71 sq in
Core Volume: 420 cu in

--------------------------------

Afco Pro Series (old design) - Grey

Width: 22.5”
Height: 9”
Thickness : 2” (double 1” tubes)
Hose/line size: .75”

Frontal Area: 202.50 sq in
Core Volume: 405 cu in

Afco Pro Series w/ 10” Fans (new design) - Brown

Width: 22.5”
Height: 11.375”
Thickness : 1.25” (single 1.25” tube)
Hose/line size: .75”

Frontal Area: 255.93 sq in
Core Volume: 319.92 cu in

--------------------------------

Roush 3v blower kit Stock Heat Exchanger - Black

Width: 19.5”
Height: 15”
Thickness : .625”
Hose/line size: .75”

Frontal Area: 292.5 sq in
Core Volume: 182.81 cu in

--------------------------------

10-12’ GT500 Stock Heat Exchanger – Light Blue

Width: 22.5”
Height: 5.875”
Thickness : 2” (single 2” tube)
Hose/line size: .75”

Frontal Area: 132 sq in
Core Volume: 264 cu in

--------------------------------

07-09 GT500 Stock Heat Exchanger - Tan

Width: 23”
Height: 6”
Thickness : 1.25” (single 1.25” tube)
Hose/line size: .75”

Frontal Area: 138 sq in
Core Volume: 172.5 cu in

S550 Heat Exchanger Available Sizes/Tech

S550 Heat Exchanger Available Sizes/Tech

 

S197 Tech -- Heat Exchanger Sizes 1

We have been testing heat exchangers for 10+ years now. As far as we know we are the only ones that test heat exchangers by tracking water temp in/out. Which is the ONLY way to accurately test a heat exchangers performance. There are too many very large variables in play to use intake air temperatures as a gauge of heat exchanger performance.

In one car alone, we had seven different heat exchanger configurations. Five in another. Three in two more cars. Some of them off the shelf units, some of them completely custom. We’ve tested up to 1500cu in of core volume.

After 10+ years of testing one thing rings true 95% of the time. The bigger the heat exchanger, the better it works. There is an argument that a bigger “face” will make up for lack of core volume a little though. If you have two 800cu in units your comparing but one has more “face”, go with that one.

Passes:

As far as “passes” goes we have also not seen any evidence to suggest that more passes are better. But there are situations where more passes hurts cooling because they choke down system wide water flow/speed due to the core not being large enough to run that many passes. The results are all over the place. The short version is don’t bet the farm on how many passes a heat exchanger has. It probably doesn’t matter.

Core Design:

We have yet to see any truth to a small XYZ whammie jammie heat exchanger with its NASA designed space age core with XXX better heat transfer out performing a bigger unit. It’s possible that’s a thing. We find it unlikely anyone will ever do accurate testing to determine if it’s true though. The rig you would need to build to do that sort of testing would cost a fortune. And a lot of time. There is no way to accurately measure them on a car. That said, we have a window of core specifications that have worked well for us and we stay in that window. We’re certainly not saying that the core design doesn’t matter.

Hose Size:

The hose/fitting size on a heat exchanger can make or break how much water you can flow. Almost all heat exchangers have .75” fittings. It’s very difficult if not impossible to achieve adequate water flow to control inlet air temps with fittings/ a system size that small. As a rough outline this is how much water speed changes with system-wide size change. Here are some specs based on using a Stewart E2512A water pump. Keep in mind most superchargers do not have an intercooler with bigger fittings than .625”. Some as small as .55”. So, don’t expect most systems with .75” hose to flow the .75” number below:

1.25” – 28gpm

1” – 21gpm

.75” – 13gpm

-----------

Measuring core sizing:

This is the only way we have found to measure them consistently.

Core size, side to side (width), is measured not including tanks, just the core.

Core size, top to bottom (height) is measured from the outside (top side, bottom side) of the last “tubes” open to airflow.

Core thickness is the thickness of the core minus any headers, footers, etc.

Most advertising you see for heat exchangers contains sizing based on overall dimensions. That is not the “working size” of the heat exchanger. The core size is.

Thick/Tight Cores Are A Problem:

Through testing we have learned that once cores get thicker than 2.625” they’re too thick to efficiently pass air though them. As an extreme example we have tested a 2.65” core vs a 3.125” core. The 3.125” core had half the airflow of the 2.65”. So yes, core size/volume is very important. But only if that volume is attained without making it too thick.

-------------------------------------------------

Specifications:

Department Of Boost Titanic Triple S550

 Width: 22.5”

Height: 16.5”

Thickness : 2.6465”

Hose/line size: .75” – 1.25” (adjustable)

Frontal Area: 371.25 sq in

Core Volume: 982.51 cu in

--------------------------------

 Department Of Boost Super Single

 Width: 24”

Height: 12.375”

Thickness : 2.5”

Hose/line size: .75” – 1.00” (adjustable)

Frontal Area: 297 sq in

Core Volume: 742.5 cu in

--------------------------------

 Whipple Oversize Option  

 Width: 22.125”

Height: 15.75”

Thickness : 3.1875”

Hose/line size: .75”

Frontal Area: 348.46 sq in

Core Volume: 1110.74 cu in

****There is a shortcoming with this HE that betrays its dimensions. It is very, very thick and has a very dense core, which makes it resistant to airflow. Thinner/taller units with a freer flowing core will shed more heat even if they have a lower core volume (not too low though). We rate our Super Single much better than this unit despite its smaller core volume. The Super Single will pass a lot more air through the core. And the Super Single can be run with up to a 1” line which is the only way to get stout water flow numbers.

--------------------------------

C&R Heavy Duty/Shelby Extreme

Width: 24”

Height: 12.4225”

Thickness : 1.75”

Hose/line size: .75”

Frontal Area: 298.14 sq in

Core Volume: 521.75 cu in

--------------------------------

Whipple 2.9L Kit Standard Unit

Width: 21.25”

Height: 15.75”

Thickness : 1.5”

Hose/line size: .75”

Frontal Area:  334.68sq in

Core Volume: 502.03 cu in

--------------------------------

 VMP Triple (GenII)

 Width: 24”

Height: 12.25”

Thickness : 1.5”

Hose/line size: 1.0”

Frontal Area: 294 sq in

Core Volume: 441 cu in

--------------------------------

 VMP Triple (GenI)

 Width: 24”

Height: 12.25”

Thickness : 1.5”

Hose/line size: .75”

Frontal Area: 294 sq in

Core Volume: 441 cu in

 

--------------------------------

LFP

Width: 21.75”

Height: 8.125”

Thickness : 2.375”

Hose/line size: .75”

Frontal Area: 176.71 sq in

Core Volume: 420 cu in

--------------------------------

C&R Standard/Shelby Comp

Width: 24”

Height: 9.6125”

Thickness : 1.75”

Hose/line size: .75”

Frontal Area: 230.7 sq in

Core Volume: 403.72 cu in

--------------------------------

Afco Pro Series (old design)

Width: 22.5”

Height: 9”

Thickness : 2” (double 1” tubes)

Hose/line size: .75”

Frontal Area: 202.50 sq in

Core Volume: 405 cu in

--------------------------------

Afco Pro Series w/ 10” Fans (new design)

Width: 22.5”

Height: 11.375”

Thickness : 1.25” (single 1.25” tube)

Hose/line size: .75”

Frontal Area: 255.93 sq in

Core Volume: 319.92 cu in

 

Air To Water Intercooler Systems – Probably More Than You Want To Know

COMING SOON!

Why You Probably Don’t Want Fans On Your Heat Exchanger

image of old fan

If you don’t want to hear facts that conflict with your opinions/assumptions/agenda, you like to be recreationally outraged, you’re easily upset, you like your safe spaces, you’re a special snowflake, you’re an unapologetic fanboy of XXXX heat exchanger or you’re simply looking for something to bitch and moan about……………..DON’T GO ANY FURTHER!! This isn’t for you!!!

The Cases For Not Using Fans And The Facts To Back Them Up In This Article

  • Fans will only move enough air through the HE core to replicate a best-case scenario of a 12-14mph vehicle speed. That’s absolute best case with every variable pushed toward the fan(s) favor. In reality it’s not going to be that good. We guess it’s more like 9-10mph. It’s irrelevant though. Anywhere in that speed range is not impressive even without factoring in the “costs”.
  • Fans only reduce water temps (when they’re effective under 12-14mph) 2-3deg best case. Which translates into a IAT drop of 2-3deg best case. Which is nearly nothing.
  • The fans hurt airflow through the core a minimum of 12% at 28mph and it gets worse exponentially as the speed increases.

Why We Wrote This

When we develop a product, we attempt to start with a clean sheet design and not take anything for granted. Especially market trends or market momentum. We don’t simply copy or modify the status quo. Who says the status quo is correct? History has taught us that a lot of the time, it’s wrong. So, in this case we went on a “deep dive” into fans and how they effect heat exchanger performance. That is what is necessary to put out the best product we can. Because of this deep dive we have good data/information on the subject. More than we have seen anywhere else…… combined. Why not post it all up in an article so everyone can learn?

Secondly, this article is pretty easy from a motivational standpoint. We are simply frustrated with the constant barrage of bad information out there about air to water cooling systems in general, and in this case heat exchanger fans specifically. We see this as a public service announcement. We care about the choices people make (and the money they spend) based on incorrect information.

Some may argue that we wrote this to support not offering fans on our soon to be released heat exchanger (2/1/19) for 2005-present Mustangs. That is 100% false. We chose not to offer a fan(s) on our heat exchanger because they are a waste of money for the end user (that’s you). It also allowed us to design/package it in a better way because we did not have to make compromises to incorporate a fan(s). Sometimes what works, and what the public at large perceives as “works” are two different things. And a lot of manufacturers will design something based on market pressure. Even if the “facts” those pressures are based on are wrong. We’re not that kind of manufacturer. We only deal in things that work.

We could have easily designed a fan(s) into our heat exchanger. It’s not exactly rocket science. That would of course driven the price up. And we’re not into driving prices up for “fluff”. We would rather lose some sales because some people just have to have fans (and bought something else), than compromise our “Design/sales morals”.

Disclaimer

We don’t contend that most of the manufacturers/vendors out there are selling heat exchangers with fans because of greed. We’ve never talked to one (and we have talked with a few) that has actually done effective testing (the key words here are “effective testing”, more on that below). As best we can remember heat exchanger fans started showing up in the early 2000’s with the Terminators and Lightnings. At first glance it seemed like a good idea (we thought it was a good idea at the time also). And we speculate that between not having any effective test data to work from and market pressure it turned into an industry wide game of “monkey see, monkey do”. We even played along for quite a few years with our own cars before we decided to get down to brass tacks and test them.

Abbreviations/Terms

We will be using abbreviations in this write up. Here is what they are and what they mean.

Ambient – Outside air temperature.

Anemometer – Basically a wind speed gauge

A2W – Air to water intercooler or intercooler system.

CFM – Cubic feet per minute (this is how fan flow is usually measured)

IAT – Intake Air Temperature. This is the air temperature measured after the intercooler right before it goes into the cylinders. This is very important.

IC – Intercooler. The intercooler is what cools the air coming out of the blower before it enters the cylinders. It is in the intake manifold and you can’t see it unless you have the blower off.

HE – Heat Exchanger. The heat exchanger is part of the intercooler system. It is the “radiator” that mounts up in the nose of the car and it sheds the heat that is picked up at the intercooler.

OEM – Original Equipment Manufacturer. This means stock. The parts, systems, etc the car came with.

Basic Topics/items You Need To Understand/House Cleaning Before Going Further

Effective testing

This is a pet peeve of ours. The word “testing” is thrown around in the hot rod world a lot. Rarely is anything we see an actual test. We don’t think we have ever seen anything even remotely close to the scientific method. We’ve never even seen a A-B-A test. Which is the most basic of tests. In most cases what we see are sample sizes of one (which is not a test). And most, if not all of those don’t have consistent control of the variables for the before and after. Which really makes it a non-test. We understand why almost nothing is actually tested. It’s hard, time consuming and very expensive. Eliminating and/or controlling variables takes considerable effort. We also understand that most of the results we see are not proof. We almost never see a test where we immediately don’t think, “but you didn’t control for X, Y and Z”. You should too. We’re not saying that what you’re seeing is useless (in some cases is it though), only that you should question it. You should even question this article. Additionally, a lot of “testing” in this industry is just badly masked advertising. Keep your eyes open.

The reason this section is titled with testing in quotes is because even though we go to great lengths to remove variables when “testing” (we go a lot further than just about anything we see in this industry) most of the stuff we have tested has the variables minimized. Not completely eliminated. We don’t have the time or money to test in the truest sense. The case of the heat exchanger fans being an example of “almost a test”. It’s more than we have seen anywhere else, but our results are still not proof. Anyway, that’s our “testing” disclaimer. We’ll use the word testing (not in quotes) from here on out. What we mean is “almost testing” though.

Testing Variables

The biggest and first variables that has to be removed when testing heat exchanger and component performance (in this case the fans) is the intake manifold and intercooler. And that right there eliminates every heat exchanger or fan test we have ever seen. You can’t use IAT’s in the manifold to collect data on HE’s. The intake air temperature is made up of:

  • Ambient air temp
  • Supercharger temp
  • Intake manifold temp
  • Cylinder head temp
  • Engine valley/vee temp
  • Engine compartment temp
  • Throttle opening
  • Time idling
  • Erc, etc, etc.

That is a LOT of variables going into a IAT reading. The cylinder head temp can fluctuate 30deg in a matter of seconds. And because the manifold is bolted to the heads the manifold has gigantic temp swings too. Same for the blower. You will see more extreme temp changes in engine compartment temp and ambient air temp (they effect IAT’s less though). The water temp change in the HE is very small by comparison (more on that below). A 30deg intake manifold swing is larger than the swing you will see at the heat exchanger. It’s absolutely ludicrous to think that you can judge HE performance by measuring temperatures inside the intake manifold. You can try and make the argument that at the end of the day IAT’s are all that matters though, so why not take the temp there. That would be wrong. If you can’t tell exactly what is happening at the heat exchanger how do you know if it is helping IAT’s or if it’s simply just a swing in another variable? The answer is, you can’t. That’s why you have to test heat exchanger performance by measuring water temp. At a minimum where it exits the HE. Better yet, where it enters and exits the HE. All of our testing of HE’s and fans over the years was done by sampling water temps. As far as we are concerned any HE test data that involves the use of IAT’s is simply put, junk data.

Water Temps In The Heat Exchanger As They Relate To The Use Of Fan(s)

For this bit we’re going to assume the HE in question is of decent size and performance.

One very large misconception that we see commented on, usually delivered as a retort. Is “But radiators need fans”. Or the smart-ass version, “Well, I’ll just remove the fan from my radiator then smart guy!”. The “logic” these retorts are based on is incorrect. An engine cooling system is not a A2W IC system. They operate in completely different temperature ranges, very different “time under heat loads” and you can run a much more effective fan on a radiator because you have more room.

Engine cooling systems run at much higher water temperatures over a given time period than a A2W system does. You’re only putting significant heat into your A2W system while making boost. The engine is putting significant heat into its system all the time. A heat exchanger will have water temps in the 5-20deg over ambient range most of the time (on a 75deg day, 80-95deg). Your engine cooling system is at a minimum of 160deg (if you have a really cold thermostat) and is usually running in the 180-225deg range. Because heat transfers faster the bigger the temperature differential a fan on the radiator is far more effective. For example:

If your radiator water temp entering the radiator is 200deg (on a 75deg day) and a fan can remove 30% more heat than no fan you’re looking at a 37.5deg drop in water temps as the water moves through the core due to the fan. This is assuming you’re driving slow enough to need the fan/the fan moves air fast enough.

If your intercooler system water temp entering the radiator is 85deg (on a 75deg day) and a fan can remove 30% more heat than no fan you’re looking at a 3deg drop in water temps as the water moves through the core due to the fan. This is assuming you’re driving slow enough to need the fan/the fan moves air fast enough.

This is assuming that heat transfer is linear, which it is not. In reality the bigger the temperature differential, the faster the heat is transferred. The heat transfer rate in reality is skewed even more toward the engine coolant/radiator.

You can run a far more effective fan on a radiator too simply because you have more room for much deeper blades. The stock radiator fan on your 2005-present Mustang moves about 3600cfm at an air speed of 29.3mph. That is effectively double the air speed you can get out of a HE fan.

There is no doubt that a HE fan(s) “works” under a certain vehicle speed (details/numbers on that below). But if you’re looking at only getting a 3deg drop in water temps (which is actually what you will see for a maxiumim), is it really “working”?

That 3deg water temp drop number in the HE by using a fan is a good number. We have tested this extensively. How much does that 3deg drop effect your IAT? If it effected it on a 1:1 ratio, which is best case scenario (it will never be as good as best case), you’re looking at a 3deg IAT drop. Which is insignificant and also impossible to accurately read at the IAT sensor.

Fan(s)

Fans are the main focus of this article and not nearly as black and white as you would think. So. this section will be quite detailed.

Fan Rating & Real-World Performance

Fans are generally rated as cfm (cubic feet per minute). The first thing to get out of the way is that fan manufacturers measure their own products flow. This should already make you suspicious. There are many, many ways to rate/measure/test the flow of a fan. Is the number based on open flow which is just the fan moving air, no restrictions such as a heat exchanger to pull or push through? We suspect that most are rated as open flow. It will give the biggest numbers for advertising purposes.

Some questions you should have in the back of your thoughts when digesting fan flow ratings:

  • What does that fan flow when it’s attached to a HE?
  • What if the HE is 1” thick?
  • What if it’s 2” thick?
  • What if it’s 3” thick?
  • What if the HE core is very dense?
  • What if the heater core is very open?
  • Will fan blade design “A” lose flow at the same rate as fan blade design “B” when faced with a restriction?
  • What voltage was the fan rated at? 12v? 13v? 14.2v (where most 2005+ Mustangs run the alternator voltage)? Or 16v? Different voltages will give different results.

There are no standard testing parameters that the fan manufacturers all use as a “zero”. So, you can have two fans that advertise the same flow, but one will flow more than the other once you get it mounted up in the place it will be getting used. Long story short, you want to take fan flow numbers with a grain of salt. If their ratings are anything like water pumps (they probably are are) their actual “in use” flow numbers will be quite a bit different than advertised flow numbers. And the same flow numbers from two different manufacturers can be completely different in reality.

Fan Testing

We tested four 10” fans to get an idea of how they stacked up in real life and to find the best performing fan to give the argument for fans its best chance.

The fans were all tested for “open flow” (they were not on a HE). Then tested on our test heat exchanger which has almost zero restriction to the fan(s). The restriction is really small at about 1/4mph. That’s in the margin for error. In this test the HE was not a factor. All fans were tested at 15v which is the only voltage we could get to stabilize consistently. Your 2005+Mustang runs about 14.2v. All of these fans moved a bit more air at 15v vs 14.2v, but it was so small it was inconsequential. All fans were tested using an Anemometer (wind speed gauge). We tested the wind speed gauge against a known wind speed (hung it out of the truck window at 40mph and 50mph) and it reads accurately.

This is the information you will see for each fan:

  • Advertised cfm rating
  • Average measured air speed across the fan face. The air speed across the face of the fan is not the same everywhere. At about 25% from the fan edge you will see your highest peak speeds. From 25% out to the tip of the blades the air speed drops about 25%. From 25% in from the edge of the fan blade to the fan motor the air speed decreases about 50%. And behind the motor the air speed is quite slow at about 20-30% of the max air speed seen toward the end of the blades. We had to eyeball average air speed and make some judgement calls as to the average across the face. Plotting everything out would have taken forever. Our seat of the pants average “calculation” was pretty much spot on with the advertised cfm of two fans, the ones that made their advertised air speed. Conclusion, our testing model and results are good. Here is a quick model of the different air speed zones across the fan. Orange is 25% less than peak speed. Red is peak speed. Yellow air speed drops from the outside edge toward the inside edge. Blue is the “dead zone” where the motor is.

  • Actual cfm rating. We got the actual cfm rating by calculating it using an online calculator. The calculator is pretty accurate. Two fans measured just about dead on in relation to their advertised rating. And two, which we thought had ridiculous cfm claims from the start, measured way off. Long story short, measured wind speed numbers accurately translated into accurate cfm numbers. Here is a link to the calculator:

https://www.engineering.com/calculators/airflow.htm

The Results:

Derale #16910

Advertised cfm – 500

Average measured air speed – 10mph

Actual cfm – 475

Perma Cool #18120

Advertised cfm – 1450

Average measured air speed – 10mph

Actual cfm – 475

Perma Cool #19120

Advertised cfm – 2350

Average measured air speed – 12mph

Actual cfm – 575

Spal #30100435

Advertised cfm – 802

Average measured air speed – 17mph

Actual cfm – 815

Clearly there is some funny business going on with fan ratings, we’re not shocked one little bit. It’s nice that two performed pretty much right on target because that verified that going from air speed measurements to cfm using the linked calculator works. It also verifies all of the findings later on in this test are sound because the measuring instrument and calculated numbers are solid.

For the rest of this article we will be using the Spal fan as the benchmark for “best fan” giving the “for fans” argument its best chance.

Understanding CFM ratings & How They Work In Reality – They’re Deceiving

The fans flow rating can be very deceiving too. The rating is cfm, that is pretty easy to understand (cubic feet per minute). But, 1000cfm with a 9in fan is a lot different than 1000cfm with a 12in fan. Sure, they move the same amount of air. But, the air speed will be slower with the bigger fan. Equal air volume through a bigger hole equals a slower air speed.

Here are some examples of how cfm and fan size can get confusing. These are the top performing fans that we could find in these diameters that are thin enough to be used as a HE fan. If you are able to run a thicker fan, and therefore deeper fan blades, those cfm numbers go up significantly for a given diameter. But you only have so much room to work with when putting a fan(s) on a HE so this is what your able to use.

We used an online engineering calculator to calculate these MPH ratings. And we use the same calculator for other bits of data throughout the article. It could be argued that the model this calculator is not an exact representation of a fan. We did check actual air speed on a few fans and compared it to the online calculator and the results were so close they were in the margin of error. Conclusion: The online calculators results are solid.

https://www.engineering.com/calculators/airflow.htm

NOTE: These fan ratings are based off of advertised numbers, not what we have tested them at (except the 10” fan Spal we’re using for all future 10” fan data).

The results are surprising:

10in fan – 802 cfm -17mph

11in fan – 844cfm - 14.5mph

12in fan – 909cfm – 13.2mph

16in fan – 1300cfm – 10.6mph

Interesting huh? The cfm rating doesn’t translate directly into more airspeed. This is because even though the fan blades are getting longer, they can’t get “deeper”. And a “deeper” blade scoops more air.

Be careful with trying to equate air speed with cfm ratings. There are a lot of variables in play before you can get to a mph through the core result. Which is what matters to you. It’s really kind of irrelevant though. After you finish this article you will see that even if fan driven air speed through the core was doubled (which it won’t, because there are no such things as fans which will fit that move air that fast), it still isn’t enough air speed to justify the use of fans. Especially when you take their penalties into account.

Effective Fan Area

This is a very important factor. And a little complicated. There is going to be some ideas/math in here that is important to understand when it comes time to analyzing the results.

The fans don’t pull air through the core evenly everywhere. The fan pulls air through the core in front of the fan blades out to the inside edges of the shroud. Not through the entire face of the HE. Here is an example of the effective fan area:

The “face” (the front side) of this HE is 22.5”wide X 11.375”tall for a area of 256sq in. That is the total amount of area that air can pass through. The effective fan area of those two 10” fans is 157sq in. That means 39% of the HE is not getting air pulled through it by the fans. We feel the only fair way to rate how fast fan driven air moves through the HE is to average it across the entire face. An extreme/impossible example to explain the reasoning is if you had a 1” fan that moved air through the core at 100mph you couldn’t honestly say that the fan moves 100mph through the entire core now could you? That would be ridiculous. If the fans move the air at 17mph (the best performing 10” fan) your average air speed through the entire core is only 10.4mph. Or in plainer terms, the fans only replicate 10.4mph in real world air speed through the entire core. We used the online calculator linked above to come up with this number.

Test Data & Results

We devised a test to collect more data on how the HE works at speed, how it works at speed with the fans on it, etc. With our professional stunt driver behind the wheel, driving in our top secret private test facility, I rode in the bed of my truck standing up (helmet on), looking over the cab, so I could take readings behind and around the HE I put up there. We found out some interesting stuff. We wish we could test this faster but 40mph was the limit for how much room we had/safety/etc. It would have been nice to have access to a wind tunnel that day!

We used a HE with one of Griffin’s high flow 1.5” single tube cores. Basically their “race core”. At 1.5” thick it’s quite thin compared to all the big heat exchangers out there. So, this is going to be best case scenario for core resistance to air flow.

We used a top end Spal 10” cfm puller (better than a pusher) fan. “But some HE’s have 11” fans that move more air” you say? We just went over that above. A larger diameter fan doesn’t necessarily mean it moves air faster through the core. In fact, most of the time the larger fan moves the air slower through the core.

Air Speed

Air speed in front of core – 38mph
Air speed no fan behind core – 26mph
Air speed fan behind core – 21mph

Air speed in front of core – 28mph
Air speed no fan behind core – 19mph
Air speed fan behind core – 15mph

One thing to bear in mind is that the HE was placed right on the cab of the truck (the aero of the truck was not giving false readings at these speeds). Effectively the HE was out in the open. The air could spill around it pretty easy. When the HE is in the front of the car there is a “pocket” of air formed in front of its face. The faster you go the bigger/deeper the pocket gets and the more air is forced though. In theory this will be on a curve going up. We can’t test this though. In theory with the HE mounted in the car you’re going to force more air through the core. And the faster you go, the more efficient it will get. There are of course a ton of variables in here though that we also can’t test. Like the aero of the grills in the bumper cover and how they effect airflow through the core as one example.

Clearly you get more air speed through the core when you don’t have a fan behind it. The fan absolutely does hinder air speed. The data shows that it hinders air speed going as slow as 28mph.

Cutting the data in half:

Air speed in front of core – 14mph
No fan behind core – 9.5mph
Fan behind core – 7.5mph

We know that data isn’t going to pan out because the fan moves the air at 10.4mph through the entire core. So that is going to be the minimum air speed. We can look at this data and extrapolate that fans moving the air through the entire core face at 10.4mph (which is our best-case scenario) is roughly replicating the vehicle moving at 14mph because the fans are moving the air through the core at almost the same rate as 14mph of vehicle speed (10.4 and 9.5mph respectively).

Core Flow Restriction Due To Blockage From Fans

So far, we have looked at air speeds that fans generate and by extension at what vehicle speed they’re effective to. 14 whole miles per hour best case scenario. What we haven’t looked at yet is the flip side of the coin. That is, how much do fans hurt flow through the core? There are no two ways about it, the fans simply being present restrict airflow through the core up past the speed at which the fans move the air. Any restriction in front of or behind the core effects air speed through it. And the fans are a really big restriction in regards to surface area. Then you have to factor aerodynamics and its nature in. Let’s looks at the data from above again.

Air speed in front of core – 38mph
No fan behind core – 26mph
Fan behind core – 21mph

Air speed in front of core – 28mph
No fan behind core – 19mph
Fan behind core – 15mph

Already at a vehicle speed of 28mph the fans simply being present are hurting flow through the core to the tune of 4mph (the difference between fan and no fan behind the core). This represents a 14% drop in air speed through the core. At 38mph the fans are hurting flow through to the tune of 5mph. This represents 15% drop in air speed through the core. Because of the way aerodynamics works this percentage will keep going up as vehicle speed increases. And it’s not linear, it’s exponential. What is it at 60mph? 75mph? 100mph? We would be guessing. But a 14% penalty at 28mph is already a big hit. What if it’s 30% at 75mph? It could be.

Now to be 100% consistent we have to factor in that the fans don’t cover the entire core face like we did when we factored it for fan effectiveness measured as an average through the core. Here is a picture of the HE we have been using as an example without fans.

fan-photo

As you can see to mount the fans there is more blockage to the core than just the fans themselves. And this is one of the better ones. Many HE’s have more blockage on the back side. We also need to consider that because of the way aerodynamics works there will be more “blockage” than the size restrictions represent. The air has to move around those blockages which increases their effective size. We’re not going to go into a whole “thing” analyzing this. It’s pointless. It’s not like the argument for having/not having fans is even close to going the way of “have”. Even at best case. So, we’re taking an educated guess based on our “eye-crometer” for this one. The fans cover 61% of the HE face. We’re guessing another 29% is compromised by the brackets/mounts/aero/etc for a total of 90% (see what we did there? Easy math). Take a look at the pic of the HE again with the fans on it. How much free flow area does it have? It’s not much. 10% is probably just about right.

If you take the total restriction area and math it out over the entire face of the HE with the restriction caused by the fans you’re probably looking at a total average net restriction across the core of 12%. And that is at only 28mph. It’s going to get worse as you go faster.

Almost all of the high-performance cars out there have flaps that open at speed across the face of the radiator fan shroud. The manufacturers didn’t spend all that time and money putting them in there because they don’t work. They put them in there because they dramatically increase airflow through the radiator at speed……because they reduce the restriction on the back side of the core. You can’t go without a radiator fan on your car so they developed the flaps. You can go without fans on your HE.

Here is the bottom line, up past a best case of 12-16mph vehicle speed fans simply being there are hurting you cooling performance considerably.

Conclusions – Some Opinion – Questions - What Did We Learn?

-Fans will only move enough air through the HE core to replicate a best case scenario of a 12-14mph vehicle speed. That’s absolute best case with every variable pushed toward the fan(s). In reality it’s not going to be that good. We guess it’s more like 9-10mph. It’s irrelevant though. Anywhere in that speed range is not impressive.

Additionally, keep in mind that we used the most effective fan at generating air speed for this test (10” Spal). Simply moving to an available 11” fan will give you a best case of a 15% drop in air speed through the core. Some HE’s have 11” and 12” fans on them. They will perform significantly worse than the examples in this article.

-Fans only reduce water temps (when they’re effective under 12-14mph) 2-3deg best case. Which translates into a IAT drop of 2-3deg best case. Which is nearly nothing.

-The fans hurt airflow through the core a minimum of 12% at 28mph and it gets worse as the speed increases. 12% is a LOT of percents!

-Even if you were to use fan(s) that were twice as good (which isn’t possible) you’re looking at them only replicating a best case of 28mph vehicle speed. That’s still not great.

-Does the best case scenario of a 2-3deg drop in IAT’s with the use of fans under 14mph offset the damage they do at every speed above that? We think no.

-Does the best case scenario of a 2-3deg drop in IAT’s with the use of fans under 14mph offset the cost of fans? We think no.

-Does the best case scenario of a 2-3deg drop in IAT’s with the use of fans under 14mph offset the amperage load on your alternator? We think no.

-Does the best case scenario of a 2-3deg drop in IAT’s with the use of fans under 14mph offset the noise they make? We think no.

-Does the best case scenario of a 2-3deg drop in IAT’s with the use of fans under 14mph offset the HE size and or design considerations that need to be made to fit those fans in there? We think no.

Cost/Benefit

At the end of the day it comes down to a cost/benefit analysis. In a perfect world you would have HE fans that didn’t cause a degradation in performance up past 12-14mph (absolute best, best case scenario). But that is impossible. So, a cost/benefit situation arises.

What are you gaining by having fans?

Best case you’re gaining a 3deg drop in IAT under 12-14mph. That is fantasyland best case. We’ll go with that though. That is all you have as far as gains go. And for what? Your IAT’s under 12-14mph don’t matter one bit. The only time your IAT is important is when you’re in the boost. While cruising around your IAT’s can be 225+deg and it’s not hurting anything. In fact, you get better gas mileage. What you see for in boost IAT’s have very little to do with what you’re seeing while just cruising around. You’re in boost IAT’s are made up of ambient air temp, the temp rise due to boost, the water temp coming out of the HE and the water speed. Very, very little of your in boost IAT is made up of what the intake manifold and blower temps are. “Heat soak” of the hard parts is a very small fraction of the heat making up your in boost IAT.

You could argue that the 3deg lower water temp while cruising with fans matters when you get into boost. And you would be correct a little. That could turn into a 3deg lower in boost IAT for the first couple of seconds that you’re in the throttle, you’re under 12-14mph and the first time the water circulates through the system. If you’re making a 0-120mph run that takes 11.5sec how much of that run was helped by the fans? 1-2 seconds? At what cost? That’s below.

What are you losing by having fans?

  • You’re losing a bare minimum of 12% of your airflow by 28mph. How much is it at 60mph? We can only guess based on some math and peripheral data, but another 12% for a total of 24% is not unreasonable. This loss of airflow is happening exactly when you need it most, when under boost. We were not able to effectively test this to the level of “brass tacks” but when we took all of the findings, data and observations we have amassed it’s reasonable to say that by 45-50mph your water temps are 3-4deg lower in the HE if you don’t have fans. Why would you give that much temperature up when you need it (under boost/moving) to gain a little airflow with fans when you’re cruising at low speeds and IAT’s don’t matter?
  • You’re also losing packaging/performance advantages. Most HE’s are right up against the back side of the bumper so fans can be fit in behind them. How much airflow are you getting THROUGH the bumper and then through the HE? Not much. What happens when you can pull the same size HE 2.5-3” away from the bumper because it doesn’t have fans on it? The answer is a lot more flow through the previously shrouded part of the HE.
  • You’re losing the cost ($$$) of the fans.
  • You’re losing the silence you get from not having two fans spinning their guts out (most of them can be heard in the car).
  • You’re losing the lower amperage draw on your alternator. Which ultimately translates into HP.
  • There are actually a lot more subtle losses due to heat transfer rates in the system but the background needed to go over heat transfer rates and their effects is quite complicated and would need its own article.

In conclusion, the choice for/against HE fans is a cost/benefit analysis for the end user. There is not going to be a one size fits all perfect solution for this. Our opinion is that the costs of HE fans far outweigh the gains in 99% of situations.

Other things of note to chew on:

The only situation where we can see having fans would help is at the drag strip for cool down between runs and through the burnout and staging. We would bet money that it would be more effective to run the pump with the car off in the pits to cool down though. You can make the argument to run both. But you will smoke your battery like that. You would need a generator, a place to plug in and a converter to go to 12v to pull that off. How many people/cars are we talking about now? Not very many go to the strip. And how many are going to be able to “plug in”? At that point just bring a damn fan to the track that runs off 110v and aim it at the front of the car.

We ran the at speed tests with the fan on and off. The fan being on or off didn’t change the air speed enough to be detectable (standing in the back of a truck). Maybe in a static test we could nail down a .5mph swing or something. We think it’s irrelevant though. As the air speed through the core goes up past the fan speed it starts to free wheel. It’s possible at 100mph that the fan has some drag just freewheeling. We can’t test that though.

A trick we learned with our 2007 shop car was to seal the HE to the A/C condenser and use the pull from the radiator fan to move air through the core of the HE during slow speed operation. That’s what the radiator fan is there for right? Slow speed cooling? And the radiator fan is a BEAST. Why add more fans to the car to cool the HE when you can simply seal the HE to the A/C condenser and get the same effect? You get all the advantages of having a HE fan(s), with none of the downsides. We have set up our soon to be released HE to work just like this. It uses the radiator fan to move air through the HE at slow speeds.

We have been doing a lot of heat exchanger, fan and water pump testing with vehicles for almost 10yrs now. We’ve known for a long time by tracking IC system water temps that HE fans are nearly useless, and a lot of the times damaging. We have seen hours, and hours and hours of data on the dash in many different situations to base our findings on. But, to really answer the question we had to go backward and “bench test” a few key things. Usually you would bench test first. Again, we already knew fans weren’t the way to go. But after we did the rest of the testing and put all the data in one spot did we realize just how bad of an idea they are.

We can’t imagine anyone looking at this data and while being intellectually honest make the claim that fans are a good idea.

We hope this article shed some light on heat exchanger fans for you.

Thanks!

Department Of Boost

Why Intake Air Temperatures Can’t Be Compared between Positive Displacement and Centrifugal Superchargers

 

 

Abbreviations/Acronyms/Definitions in This Article:

- The words Blower and Supercharger are interchangeable.
- Centri = Centrifugal
- PD = Positive Displacement. This includes roots, roots improved, TVS and Twin Screw blowers.
- IAT1 = Intake Air Temperature before the blower.
- IAT2 = Intake Air Temperature after the blower and after the intercooler.
- IAT = Unless noted otherwise, I’ll be using IAT interchangeably with IAT2. It’s the IAT that really matters, and in a lot of cases the only one you know.
- DT = Blower discharge temp. This is what the temperature of the air is after it comes out of the blower and before it passes through the intercooler. This temp is rarely sampled in anything short of a full bore race car.
- IC = Intercooler.
- A2W = Air to Water. This is a type of intercooler system. All PD blowers come with these if they have an IC at all.
- A2A = Air to Air. This is the other type of intercooler system. Most Centri blowers come with an A2A. But a few come with A2W systems.
- Ambient or ambient temp = Outside air temp.
- Air charge = The compressed/heated air after the blower.
- Charge Air Cooler (CAC).
- Low Temp Radiator (LTR).
- Mass airflow sensor (MAF).
- WOT = Wide Open Throttle
- TB = Throttle Body

A few words on intercooler system/parts names/definitions/descriptions/and confusing stuff.

In different segments of the automotive world, some components are called different things but they’re exactly the same. The OEMs call one thing “A,” while the aftermarket calls the same part “B.” And the Ford crowd may call it “C.” And the tuner crowd can call it “D.” So, obviously, this can get confusing. I’ll clear that up here. Well, clear it up for this article. I won’t be fixing the internet!

In the “Mustang World” and This Article, You’ll See These Words Used for These Things:

-Intercooler. This is the cooler that sits in the intake manifold under the blower on PD blown cars.

-Intercooler. This is the cooler that sits behind the bumper cover and in front of the radiator/air conditioning condenser on A2A Centri blown cars.

-Intercooler. This is the cooler that sits in the “box,” usually in the engine compartment the air charge is run through on A2W Centri blown cars.

Confusing huh? Three different “intercoolers.”

-Heat Exchanger. This is the cooler that sits behind the bumper cover and in front of the radiator/air conditioning condenser on PD blown cars.

-Heat Exchanger. This is the cooler that sits behind the bumper cover and in front of the radiator/air conditioning condenser on A2W Centri blown cars.

In the World of OEM Manufacturers, You’ll See These Words Used for These Things:

-Charge Air Cooler (CAC). This is the cooler that sits in the intake manifold under the blower on PD blown cars.

-Charge Air Cooler (CAC). This is the cooler that sits behind the bumper cover and in front of the radiator/air conditioning condenser on A2A Centri blown cars. But there are no OEM blown Centri blown cars, so really you’ll only see this from the OEMs when describing turbo setups.

-Low Temp Radiator (LTR). This is the cooler that sits behind the bumper cover and in front of the radiator/air conditioning condenser on PD blown cars.

And One More:

Technically all of the intercoolers, heat exchangers, LTRs, CACs, etc. are……………..heat exchangers.

As you can see, it doesn’t take much for confusion to ensue. I’ll be using “Mustang World” terminology in this article.

“Centri Blowers Have Lower Intake Air Temps than PD Blowers Do!”

“Centri Blowers Run Cooler than PD Blowers Do!”

“Centri Blowers Don’t Heat Soak Like PD Blowers Do!”

I see the above quotes (and more like them) all the time. Someone will say something along the lines of “Centri blowers have lower IATs than PD blowers do.” That statement, in some cases, is true. But in other cases, it’s completely false. And there’s a 99.9% chance that people making that statement have no clue what they’re actually talking about. They’re probably repeating what others said. And that person didn’t know what they were talking about either. They’re making the blanket statement that Centri blowers always have lower IAT2s than PD blowers do, and that couldn’t be any more wrong. It’s a fairly complicated situation to understand, and most people, even people in the go fast parts industry (especially retailers and dyno operators/tuners), don’t possess the information to make statements like the above. So, to sum up, when you hear people making the above statements, you can be almost certain that they’re talking from a position of ignorance.

Some Basics

To fully understand why you can’t make blanket statements like “Centri Blowers Have Lower Intake Air Temps than PD Blowers Do!” you’re going to need a good understanding of a few things. Here they are:

 

Why You Have An Intercooler

Compressing air (boost) creates heat. Heat at a certain point causes detonation in the motor. Detonation is when the fuel’s octane can’t cope with the heat being generated. This results in cracked rings, cracked pistons, melted pistons, broken connecting rods and sometimes even cracked engine blocks. Detonation and temperature control is obviously a huge thing. You can turn a motor to scrap in a matter of a second if your IAT’s are too high.

Thankfully in the modern age the engine management systems (ECU/ECM/Computer/whatever you call it) are incredibly good and have all sorts of fail safes built in. In most cases if your IAT’s are too high you won’t turn your motor to scrap. The ECU will know that the IAT’s are too high and in turn will retard the ignition timing dramatically to keep everything in one piece. The penalty for that is a massive loss in horsepower though. It is not uncommon for a 500hp car to lose 100hp. I’ve seen 600-800hp cars loose 250hp when IAT’s aren’t kept in check. So, you may not blow motors up when IAT’s get out of hand like in the old days. But you do pay a huge HP penalty.

Most tuners (and OEM’s) want IAT’s below 135degF and set the ECU to pull timing at anything over that number. If you’re running e85 or good race fuel you can push that number up some. But that doesn’t apply to most people.

What’s the Difference between an Air to Air and Air to Water Intercooler System?

You’ll find two types of intercooler systems in most applications. Air to Air (A2A) and Air to Water (A2W). All PD blower systems use A2W IC systems. Most Centri blowers use A2A IC systems. But a few Centri blowers do use A2W.

Air to Air

A2A systems are fairly simple. The blower discharge air is run through an A2A IC that sits up behind the bumper cover and in front of the radiator. The hot air from the blower goes through the IC (inside) while the cooler ambient air is moved across/through it (outside). The temperature difference between the inside and outside of the IC cools the air charge. The air charge is then piped into the motor/TB/intake manifold—a very simple system with no moving parts.

Here is a picture of one. The red arrow is pointing to the intercooler. The green arrows are the piping that’s feeding the air from the blower to the intercooler and then the cooled air to the TB/intake/motor.

Air to Air Intercooler

Air to Water

A2W systems are quite a bit more complicated than A2A systems. Because PD blowers sit on top of the motor, it doesn’t leave enough room to run a 3”+ pipe out to an A2A IC and a 3”+ pipe back in. That would be a MESS even if you got it to work. So, PD blowers have the intercooler inside the intake manifold under the blower discharge port. Well, some are blowing “up” into an intercooler. But you get the point, the blower blows air directly through the intercooler.

Here’s a picture of an intercooler (blower removed)

.

Air to Water Intercooler

Water is pumped through the intercooler, which is then pumped out to the heat exchanger, which is located behind the bumper cover/in front of the radiator (pictured here).

Air To Water Heat Exchanger

Compressing Air

When air is compressed, it heats up. In a perfect laboratory environment with a 100% thermal efficiency, compressing air to 1psi will raise its temperature 9.89deg (all temp measurements are in Fahrenheit). But, that’s in a perfect environment. Superchargers are not a perfect environment. They have some inefficiency when it comes to compressing air. Some more than others. And different blower speeds will result in an even greater variation. It can get confusing, so here are a few “data points” to consider/put in your memory banks:

- Twin Screw blowers are the most thermally efficient of the blowers. This is because they’re actual compressors where everything else is a “blower” to one degree or another. You’ll see about 12deg/psi of temp gain with a Twin Screw.

- TVS blowers are almost as good as a Twin Screw when it comes to thermal efficiency. Eaton has done a hell of a job making a Roots Improved blower (which is what a TVS really is) act like a Twin Screw. With a TVS you’ll see about 13deg/psi of temp gain.

- Centri blowers are not quite as thermally efficient as the Twin Screw and TVS blowers. They clock in at about 13.5deg/psi of temp gain.

- Roots Improved blowers are the least thermally efficient “popular” blowers out there at about 14deg/psi of temp gain.

- A true Roots blower (think old school blower with carbs on top) is the least thermally efficient at 16-20deg/psi of temp gain. You don’t see these much anymore though.

But Wait, There’s More.

- If you put a blower on that’s too small for the HP level that you’re trying to run at, you’ll have to spin it faster. Which will push it out of its thermal efficiency range. And the closer you get to the maximum RPM, the more heat they’ll make (it’s exponential). For example, a properly sized Roots Improved blower can have lower discharge temps than a Twin Screw that’s too small for the job.

- If the blower has an inlet restriction—like the elbow is too small (which you usually can’t improve), the throttle body is too small, or the cold air intake is too small—you’ll have to spin the blower faster than one that has properly sized inlet components. This is another case where a Roots Improved blower can have lower discharger temps than a Twin Screw.

So How Much Heat Are We Talking About Here?

- A correctly sized Twin Screw making 10psi will get you a temp rise of about 120deg. But then you have to add that to the outside air temp (ambient), which we’ll say is 80deg. That is a total discharge temp of 200deg.

- A correctly sized Centri making 10psi will get you a temp rise of about 135deg. Then add 80deg ambient, and you have 215deg. Not a massive difference. But when your goal is to have a maximum IAT2 of 135deg, the extra 15deg the centri is making represents are fairly large percentage.

Now let’s turn up the boost.

- A correctly sized Twin Screw making 15psi will get you a temp rise of about 180deg. Then add the ambient temp, which is 80deg. That’s a total discharge temp of 260deg.

- A correctly sized Centri making 15psi will get you a temp rise of about 202.5deg. Then add 80deg ambient, and you have a 282.5deg discharge temp.

At this point, the “out of the box” intercooler systems are struggling to keep IAT2s below 135deg (some won’t even be able to). That extra 22.5deg of discharge temp from the Centri is absolutely making a difference.

Now let’s turn the boost up one more time.

- A correctly sized Twin Screw making 20psi will get you a temp rise of about 240deg. Then add the ambient temp, which is 80deg. That’s a total discharge temp of 320deg.

- A correctly sized Centri making 20psi will get you a temp rise of about 270deg. Then add 80deg ambient, and you have a 350deg discharge temp.

At this point, we’re talking about some serious heat. There isn’t an “out of the box”  intercooler system that will keep these sorts of temps down to a safe level (under 135deg). You would be hard pressed to build a custom A2W that can keep up. And you will never get an A2A that will get the job done.

Heat Transfer – Transfer Medium

Water transfers heat 24.17 times faster than air. Let that sink in. The water in an A2W system will transfer heat 24.17x faster than the air in a A2A system.

Water transfers heat 24.17x faster because it’s more molecularly dense. That means there’s more “stuff” to whisk the heat away. It also means that, for a given volume, let’s say a cubic foot, there’s more “storage” capacity to “store” that heat. Sounds like a clear winner, right? Give me an A2W setup any day! Well, just like most things in life, there are flip sides and “in this cases”…. Keep reading.

The Intake Air Temp Sensors Aren’t the Same

Right here is where the biggest confusion about IATs between PD and Centri blowers comes from. They don’t use the same kind of sensors. And they act wildly different, and they don’t give comparable data.

PD blowers have what I call a “bulb style” sensor. They react to temperature changes immediately. This is why you see the OEMs using them for their blower applications. They all use basically the same sensor. And the aftermarket uses OEM sensors in their kits. They’re instantaneous, accurate, inexpensive and reliable. Here’s a picture of one.

“Bulb” Style Sensor

Centri blowers “re-purpose” the car’s stock IAT sensor that’s built into the mass airflow sensor (MAF). They can do this because, unlike a PD blower, a Centri unit is blowing through the MAF with boost pressure (the MAF is before the blower on a PD setup so it “sucks” through the MAF). There’s a problem with using the IAT sensor built into the MAF though. It was never designed to deal with a blower application. The IAT sensor in the stock MAF was designed to measure air temps going into the motor that weren’t under boost. That means the sensor wasn’t designed to react quickly or to deal with really high spikes in temperature. It doesn’t need to when used as intended. In a naturally aspirated use, it will never see the extreme fluctuations that a boosted application will.

What’s the net result of using an IAT sensor that wasn’t designed for blower applications? Well, it’s problematic and not accurate at all.

The biggest issue is that the IAT sensor can’t “keep up” with radical temperature changes (going into boost). So, what you get is incorrect data. It takes the IAT sensors built into MAF sensors about 8sec to stabilize or “catch up.” Here’s an example of what happens:

You’re cruising down the road at normal speeds and not in boost. Your IAT temps are effectively ambient, let’s say 75deg. Your car makes 10lb of boost at WOT, which is an additional 135deg (roughly), which gets you a discharge temp of about 210deg.

Now you whack the throttle wide open. Unlike the bulb style IAT sensor used with PD blowers, the MAF IAT sensor can’t keep up with that temperature change. A tuner friend did a test to show how long it takes for the IAT sensor to stabilize and actually show you the correct IAT temperature. He did this for himself, but he posted the results to help educate the public. Here’s what he found out.

It took 7.88sec for the IAT sensor to read the actual intake air temp of 142deg. The rate at which the sensor “caught up” wasn’t linear (graph below). There’s a curve to it. That means, when you first go WOT, the sensor is WAY behind. Only as time elapses does it start to catch up faster. What does this mean in the real world?

3v Tech

Boosting the 3v with Positive Displacement Superchargers – Almost Everything You Need to Know
Department Of Boost’s Commitment to Fact

The performance automotive aftermarket industry, especially the forced induction portion, is littered with “fuzzy math”, half-truths, and in some cases outright lies. We see it every day, all day. In some cases, we think this problem is from ignorance on the part of the industry. In others, it’s obviously an attempt to muddy the water or a blatant lie to drive sales. It makes us crazy. It should make you crazy, too.

We commit to you to always tell you the full truth and relay the facts as we know them. Do we know everything? No, of course not. No one knows everything about an entire subject. And new theories and methods are continually being discovered. Additionally, more and more “wives tales” or “internet truths” are being debunked daily. But we’ll give you the unvarnished truth as we know it at the time. And with a healthy fear of coming off as arrogant, we know a lot.

We’ll always provide you with technical data to the best of our abilities. We’ll never give you half-truths. And we’ll never lie to you so we can sell more product. This is our commitment to you.

If you find something we wrote that’s not fact (that’s possible), and you have evidence it’s not, please email us and let us know. We’ll take a look at it and, depending on circumstances, update the article.

Disclaimer/Notes:

Before you read this, there are a few things to get out of the way.

-The 4.6L 3v found in 2005-2010 Mustang GTs has been around forever at this point. There’s no mystery left to it. It’s a known quantity and there are enough of them in enough states of tune to know what works and what doesn’t. What follows is information based on all of our experience/data.

-We quote horsepower (HP) at the rear wheels on a Dynojet dyno.

-All HP numbers quoted (if not otherwise noted) are while using 93 octane gas.

-All the HP numbers quoted are REAL HP numbers. Not fantasyland “hero run” numbers. Not a number from an optimistic dyno. Not a number that someone inflated in a post on the web. Not rounded up. All numbers are based on the car being at full operating temperature. The numbers quoted are based on a ton of examples we have seen with our own eyes and are numbers that you can achieve with your car in the real world.

-Most statements you read are to be regarded as “most of the time.” There are a zillion and one variables when dealing with motors/boost. You’ll probably be able to dig up one example that applies to every statement in here that makes it “untrue”. We’re aware that those variables are out there. But it would be impossible to write something like this and cover every single variable. What you’ll be reading is what you can expect most of the time. It’s not meant to cover wild combinations or “flyers.”

For example, we consider the pump gas octane limit on the 3v to be about 650rwhp. But we’ve gone from 650rwhp to 775rwhp on a 3v (the same car) with just a blower/manifold/CAI change. Both combos were run at 20lb of boost. How is that possible you ask? Well, it involved a “unicorn” combination. The 650rwhp was made with a 2.3L Whipple/Whipple manifold spinning 18,500rpms running a twin 72mm throttle body and a 127mm cold air kit/mass airflow meter. The 775rwhp was made with a 3.4L Whipple with a Crusher inlet/R-Spec manifold spinning 11,900rpm’s running a twin 72mm throttle body and a 156mm cold air kit/mass airflow meter. There are a lot of factors as to why this is possible that this article can’t cover. At the end of the day, it comes down to efficiency…………………..and money. It happens that piles of money will get you more. Imagine that!

Anyway………statements in this article should be considered as “most of the time.”

-This article will have some “sales” in it. There really is no way for us to get all the information across without mentioning our own products. Additionally, we got started as a company by offering stuff for the 3v motor, so our first product was targeted specifically at what was already in the marketplace. Because we got to assess the existing playing field and design products directly to compete in it, we ended up with some really good solutions for the 3v. So yeah, we’re going to mention our stuff.

Why We Wrote This

We wrote this for two reasons:

Even though blown 3v’s have been around for about a thousand years now, we still see absolutely horrible information posted up on forums, Facebook, in magazine articles, etc. It’s still treated as a little bit of a mystery. And that’s not the case at all. We wanted to provide one spot where people can get all the information they need about supercharging the 3v. Well, supercharging using positive displacement blowers. But a lot of the information applies to centrifugal blowers too.

It pains us to see so much false/ contradictory information out there. Superchargers aren’t inexpensive. And it frustrates us to see people spend their hard earned money, a lot of hard earned money, on blower kits that don’t fulfil their needs/expectations, mods they don’t need, combinations that don’t work, etc. Many many moons ago, before we were in the business, we bought a garbage supercharger system for a 3v that didn’t fill our needs. And then we threw all the wrong parts at it to get where we wanted to be…..and never got there. It sucked. Hopefully we can help you not to make the same mistakes we did.

The other reason is that we, of course, want to sell more product. And we’re hoping that by shining light on the realities of blown 3v’s more people will choose to go with what we offer. We do this to make money after all!!!

Terms and Abbreviations

We use the words supercharger and blower interchangeably. For this write up, they’re the same thing. We’ll be using a lot of abbreviations in this write up. Here’s what they are and what they mean.

CAI – Cold Air Inlet. This is what most people call the assembly that includes everything from the air filter all the way to the throttle body. Some of them aren’t actually “cold air” inlets, they’re hot air inlets. But this is what the community/industry has settled on as the name for it.

Duty Cycle – The Duty Cycle is an expression of how hard a fuel injector or fuel pump is running in comparison to its maximum ability. A 50% duty cycle means that a particular component is running “half way” maxed out.

ECU – Electronic Control Unit. This is your car’s computer. It’s sometimes also referred to as PCM, ECM, etc.

FPDM – Fuel Pump Driver Module. This/these are what “drives” the fuel pumps for the ECU. Think of them as the brains of the fuel pump(s).

HE – Heat Exchanger. The heat exchanger is part of the intercooler system. It’s the “radiator” that mounts up in the nose of the car, and it sheds the heat that’s picked up at the intercooler.

HP – Horsepower.

IAT – Intake Air Temperature. This is the air temperature measured after the intercooler right before it goes into the cylinders. This is very important.

IC – Intercooler. The intercooler is what cools the air coming out of the blower before it enters the cylinders. It’s in the intake manifold, and you can’t see it unless you have the blower off.

lph – Liter Per Hour. This unit of measurement is generally used when describing the abilities of a fuel pump(s).

MAF – Mass Airflow Meter/Sensor.

NA – Naturally Aspirated. A motor with no forced induction (blower or turbo) is naturally aspirated.

OEM – Original Equipment Manufacturer. This means stock. The parts, systems, etc. the car came with.

PD – Positive Displacement. This is the type of supercharger we’re talking about in the write up.

rwhp – Rear Wheel Horsepower. This is the horsepower measured at the wheels on a chassis dyno.

TB – Throttle Body.

TQ – Torque

VVT – Variable Valve Timing

Almost Everything You Need to Know

Overview

The 4.6L 3v in the 2005-2010 Mustang GT likes boost. It likes it a lot. Let’s face it, NA the 3v is a bit of a dog. Even when you throw the entire catalog of go-fast NA parts at it, you still won’t have a ton of power. $10,000 worth of NA go-fast goodies/built motor will get you about 420rwhp and not much torque. Not only is that a lot of money, that also represents a lot of time. It’s no wonder why most people go for a supercharger kit. They’ll make 450rwhp and 450rwtq for far less money and far less time.

The Limits of the Stock 4.6L 3v Motor

Hard Parts

Connecting Rods and Pistons:

The stock 4.6L 3v connecting rods and pistons will take up to 450rwhp at 6,000rpm. Anything above that puts you firmly in the danger zone. The likelihood of chucking a rod out of the motor is high if you push the limits.

Crankshaft:

The stock 4.6L 3v crankshaft is surprisingly robust. It’s been run up to 800rwhp in a few combinations we’ve seen and not let go. Most builds don’t need a forged crank.

Engine Block:

The stock 4.6L 3v engine block is very robust. The stock block has been run up to 1350rwhp and held up. Can it handle more? Maybe, we don’t know of anyone making more power than that with the 3v though.

Valvetrain:

The stock 4.6L 3v valvetrain, when used in conjunction with the correct valve springs and VVT lockouts, will hold up to 7,800rpm. This is where the ECU stops being able to “calculate,” so, as far as we know, no one has tried to spin one faster. You won’t be concerned with this many RPMs though. When running a PD blower, you simply don’t need or want to spin the motor that fast in anything short of a full-blown dedicated drag car. Then MAYBE you would spin the motor that fast.

Heads:

The cylinder heads actually flow quite a lot for a stock “non-performance” head. And big flowing heads are not as critical as they are on NA motors. We don’t think that it’s worth porting heads until you’ve eclipsed 700rwhp.

Exhaust Manifolds:

The stock exhaust manifolds aren’t THAT bad. They certainly aren’t an old school “log manifold”. They’re more of a cast shorty header in design. On that note, don’t ever buy shorty headers for the 3v. If they make any more power, it’s 1-3rwhp. Not nearly worth it. Anyhoo, the stock manifolds are pretty good up until about 600rwhp. Headers certainly don’t hurt. But they’re expensive, a PITA to put on, and add heat to the engine compartment, which you don’t need. Best to hold off on them until you actually need them.

Boost “Limits” and Fuel Octane

Something that’s not widely understood in general and about the 3v specifically is the boost/fuel octane limit.

Octane in simple terms is the fuel’s ability to resist detonation (or, more specifically, pre-ignition). Pre-ignition/detonation is when the fuel explodes/ignites inside the cylinder before the piston is at the top of its stroke and before the spark plug fires. This is bad. Detonation happens when the fuel octane can’t prevent that “explosion.” When you add boost, the pressure inside the cylinder increases dramatically over what you would see NA. Add to that the heat generated as the byproduct of making boost, and, at some point, the fuel octane won’t be able to prevent detonation. You’ll punch holes in pistons, break connecting rods, and sometimes break blocks. So clearly detonation is bad. For this “exercise,” we’re going to assume that the IC system is working correctly and the IATs aren’t too high. We’ll simply be talking about boost pressure and the fuel’s ability to prevent detonation.

The boost limit on 93 octane gas for the 4.6L 3v is about 18psi. This is assuming that the motor has at least forged rods and pistons. But not all forged motors have the 3v’s stock compression ratio (9.8:1). So the 18psi figure can go up or down depending on what the compression ratio of the actual motor in question has. We’ve run 20psi safely on 93 octane at a compression ratio of 9.25:1. There’s no hard and fast rule for how much boost you can run with X.XX:X compression ratio. That’s something you’ll need to discuss with your tuner.

Why bring up the octane limit? There are a couple of reasons. It’s obviously not bad knowledge to have. And if you’re planning on going for big HP and you’re limited to running 93 octane pump gas, you’ll be riding the edge of the fuel’s limit. You need to understand what’s going on so you can safely achieve your goals.

The “good news” is that most of the blowers available for the 3v don’t move enough air to make 18psi. That’s not really “good news” if you’re trying to make big power. But it does make the whole octane limit thing a moot point for a lot of blowers/most people. There’s information later in this write-up about what blowers will make for boost and their maxed out HP capabilities.

For those that have a blower that can make over 18psi and want to run 93 octane gas, there are things you can do to make that possible.

Boost is simply a measurement of restriction. We’re not going to go into the entire concept of boost in detail here, it’s very complex. But in short it works like this: the more restrictive the motor (the ability to push air through it), the more boost you’ll make for a given blower speed. If you reduce that restriction by using ported heads, big cams, a stroker kit, big exhaust, etc., you’ll reduce the restriction and boost will drop. You’ll still be moving the same amount of air through the motor so you’ll make the same power, but it will be at a lower boost level.

If you have a blower that will make 22psi on a 4.6L 3v (which is about 775rwhp) and you want to use everything that blower has to offer but still run 93 octane gas, you need to reduce the motor’s restriction. You could, for example, run a BOSS block stoked to 5.3L, big ported heads, big cams, big headers, and big exhaust. That reduction of restriction will drop the boost to about 18psi (lots of factors here, these numbers aren’t set in stone) and allow you to run 93 octane and still have your 775rwhp. Those engine mods you did didn’t “make” more power. They allowed you to run the blower at a “775rwhp blower speed” and stay under the octane limit. You may pick up a few HP because you’re decreasing how hard the blower as to push, which means it’s more efficient, but that’s very small and a subject for another time.

Most people won’t need to worry about octane limits with the 3v. Most of the blowers won’t make enough boost/move enough air to make it an issue. And very few people are shooting for over 600rwhp. Well, not many people make it. But if you’re one of the people planning on “going big” but running 93 octane gas you need to plan your combination right from the start to achieve that goal.

 

What Will the Blowers Make?

This is a tricky question and quoting power numbers these days is very difficult because the industry and the public as a whole use “fuzzy math” when making claims. What does “How much power will it make?” really mean? Are we talking about a stone stock motor with stone stock exhaust? Are we talking about a built motor with ported heads, big cams, high compression pistons, monster exhaust, a huge throttle body, and cold air intake? Or somewhere in between? Are we talking about 91 octane gas or 93? Are we talking about E85? And then just to make things really fun you can take the same car to 5 different dynos on the same day and get five different power readings that can be as much as 75hp apart! Don’t believe us? Check out this article from Hot Rod Magazine. As we’re sure you can tell, there’s going to be a huge difference in “what it makes” between stock and wild. And if you’re adding E85 to the mix, it blows the whole estimate right out of the water.

That said, here are some reasonable numbers that are based on the blowers running on stock 4.6L 3v motors (aside from forged rods/pistons so parts don’t fly out) running 93 octane gas, on the same dyno, on the same day. These numbers are based on the blowers spinning at 18,000rpm, which is their effective safe limit. These numbers can move up or down depending on other variables.

Keep in mind none of these blowers will make this power out of the box. At an absolute minimum, they would all need fuel injectors and fuel pump upgrades to see these numbers. Some will need more supporting mods than that. None of the kits are capable of running the maximum power the actual supercharger can make when you get one.

On 93 octane gas, listed least to most:

-Roush M90 1.6L will make about 400-420rwhp.

-Magnuson Magnacharger 1.9L will make about 570-580rwhp.

-Edlebrock EForce 2.3L TVS will make about 580-590rwhp.

-Kenne Bell 2.6L Stage I will make about 585-595rwhp.

-Kenne Bell 2.6L Stage II will make about 590-600rwhp.

-2007-2012 GT500 2.0L M122 (ported) will make about 605-615rwhp.

-Saleen Series VI 2.3L will make about 620-640rwhp.

-Whipple 2.3L will make about 625-645rwhp.

-Roush R2300 2.3L TVS will make about 625-645rwhp.

-Kenne Bell 2.8L and 2.8LC will make about 680-695rwhp.

-2013-2014 GT500 2.3L TVS will make about 685-700rwhp.

-Kenne Bell 3.2LC will make about 715-725rwhp.

-Department Of Boost 3.4L 3v R-Spec will make about 750-775rwhp.

On e85 these blowers will make:

The following blowers (which are also in the list above) are capable of making more boost than can be safely run on 93 octane gas. That means to run them all out on E85 or race fuel is needed. E85 is by far the best choice because E85 has amazing cooling properties and is incredibly inexpensive compared to race fuel. Here is a list of those blowers and what they can make on E85. Keep in mind getting these numbers will require very, very high dollar fuel systems and a truckload of supporting mods. Listed least to most:

-2013-2014 GT500 2.3L TVS will make about 810rwhp.

-Kenne Bell 2.8L and 2.8LC will make about 850rwhp.

-Kenne Bell 3.2LC will make about 1100rwhp.

-Department Of Boost 3.4L 3v R-Spec will make about 1200rwhp.

-Department Of Boost 4.0L 3v R-Spec will make about 1300rwhp.

-Department Of Boost 4.5L 3v R-Spec will make about 1400rwhp.

“But, but, my uncles plumber’s brothers Walmart greeter girlfriends dog groomer knows a guy that saw a post on a forum where XYZ blower made 1000hp more than that on a 3v!!!! Those numbers aren’t right!!!!! You’re full of crap!!!!”

The numbers listed above can go up or down based on conditions, fuel used, how safe they’re tuned, how happy the dyno they were on is, other supporting modifications, etc. They’re simply a representation of what you can expect out of the above blowers when they’re compared to each other under the same conditions.

Fueling/Fuel Systems

Fuel systems can get extremely confusing because there are an incredible number of choices and different combinations for different power levels and fuels used.

We’re going to leave this section to our friends at S&H Performance (sandhperformance.com). They specialize in fuel systems, and they’re who we go to for our fuel system needs, suggestions, requirements, help, etc. This is their specialty, not ours.

Here is something that Jeremy from S&H wrote up for us:

S&H Performance – Pump Gas (93 Octane) Systems

So first off. Don’t come at me with the “I made 520rwhp with just 39lb injectors and a BAP” crap. So what? So the stars aligned and you had a generous dyno, 18.5 volts at the pump, and perfect weather. That was on the ragged edge. Running stuff on the ragged edge is asking for trouble nor smart for anyone else to follow because you got lucky and swear by it on YOUR car. This goes for any example and not just the one above. Setups can vary as much as 25-50% from one another on the extreme end. In reality, on healthy systems, 10-20% difference is not uncommon.

Disclaimer. Throw manufacturers’ claims out the window! XXX product will never perform on the car as well as it did in a controlled lab test, period. Nuff said? Yes, on a healthy system, XXX product should support YYY power on ZZZ setup. That doesn’t mean it will when you get it on YOUR car.

These stats will be averages for most power I’ve seen with some safety put it because I’m not in the business of helping people blow their cars up. These are my numbers that I’ve seen personally on my car or on cars I’ve worked on or built systems for and received feedback from customers.

HP numbers are at the wheels (rwhp) with 93 octane gasoline.

Pump Wire Upgrades

-10awg wire upgrade to FPDM plug will get you an 8-12% drop in duty cycle.

-8 wire a few percent more.

-If you run two pumps on one FPDM, -10awg is fine, -8awg is optimal.

Always run the fuse closer to the power source, and always run a larger amperage relay than what you need. My wire setups use a 30amp fuse and a 40amp relay.

16-18Volt Pump Boosters (BAPs)

I personally would never run a BAP on a stock fuel pump past 475rwhp. It’s a temporary solution that’s easy to install until you can afford a better solution. Don’t install a BAP without running a wire upgrade feed for it, period.

Fuel Pump Combinations Using the OEM Fuel Hat

-OEM pump. 180-200lph, 375-400rwhp capable on boost. Don’t do this!

-Walbro 255lph pump. 450-475rwhp capable like the BAP.

-340lph pump. 525-550rwhp capable. Don’t mess with any brand besides DeatschWerks (DW) or AEM; they’re the proven most reliable with quality components. Any other brand is a crapshoot. Wire upgrade required at this point.

-Walbro 400lph pump. 575-600rwhp capable. Wire upgrade required at this point.

Fuel Pump Combinations Using the GT500 Dual Fuel Pump System

-OEM pumps. 650rwhp capable. Comes with harness second fpdm and wire/relay upgrade already. A lot claim it can handle more, but I’ve seen them max at 600-625rwhp, so I can’t justify a higher rating.

-Two 255 pumps. 700rwhp capable.

-Two 340lph pumps. 800rwhp capable. Again AEM or DW. DW is direct fit. Any other pumps are a pain to fit but can be done.

-You can add a fuel pump booster (BAP) to these higher flowing pump combos and make an additional 100hp on top of what’s listed.

800rwhp, the Return-Less/Return Threshold

What’s the difference between a return-less and return fuel system?

Return-Less Fuel System – The OEM system is return-less. And it’s exactly what it sounds like. The fuel goes from the tank to the motor and never comes back. The amount of fuel sent to the motor is controlled by the computer which pulses the fuel pump(s) to get just the right amount.

Return Fuel System – This style system is also exactly what it sounds like. Fuel is sent from the tank to the motor. The fuel that’s not used is returned via another fuel line back to the tank. The amount of fuel returned is metered by a fuel pressure regulator that maintains a pre-set fuel pressure in the system.

The discussion/reasoning on why one system is better than the other under what situations and why is very complex and very long. Way too long for the purpose of this article.

At 800rwhp, I like to see the OEM fuel system converted to a return system. At 800rwhp, your stock lines, rails, and filter become a restriction. And the pulse modulated return design is bumping into its maximum capabilities.

Return Fuel Systems

You do make a little more power per pump than the same pump(s) in a return-less system due to the design and regulator returning fuel to the tank…so I didn’t relist any of the pumps I already spoke about above. Keep in mind, as you run higher power numbers, your system can start to vary more wildly from the average. Over-building your fuel system at this point is not a bad idea.

-2 400lph pumps. 1000rwhp capable.

-2 450lph pumps. 1200rwhp capable.

-3 255 pumps. 1000rwhp capable.

-3 340lph pumps. 1200rwhp capable.

-3 400lph pumps. 1600rwhp capable.

-3 450lph pumps. 1800rwhp capable.

Fuel Line Size

8AN or 10AN? Planning on more than 1000rwhp? Then go 10AN. 1000rwhp and below, go 8AN.

Wire Size

10awg minimum wire for return pumps Consider 8awg for more than 2 pumps.

Fuel Injectors

Gasoline rating on boosted setups. I highly recommend reading this link if you want to learn more about selecting injectors.

http://performanceparts.ford.com/download/charts/Fuel_Injectors_and_Adaptors.pdf

Ford/Bosch 24lb. Newer design, available in ev6 body/internal design with uscar connector. Excellent spray pattern for 2v/3v/4v heads. Great control/mileage. Original equipment on the 3v.

Ford/Bosch 39lb. 20+ year old ev1 body/internal design injector that can be found with either jetronic or uscar connector. Subpar pulse angle and control by today’s standards. Cheap entry level injectors with fair control/mileage. 450-475rwp rated. Don’t recommend using them on a 3v personally or at all for that matter. A lot of imitation versions of these out there as well.

Ford/Bosch 47lb. Newer design, available in ev6 or ev14 body/internal design with uscar connector. Excellent spray pattern for 2v/3v/4v heads. Great control/mileage. 550-600rwhp rated. Excellent injector choice for a stock block boosted setup.

Ford/Bosch 55lb (580cc). New design, available in ev14 uscar connector. OE on the 2013 GT500. Requires height spacers for GT use. Excellent spray pattern for 2v/3v/4v heads. Great control/mileage. 675rwhp rated.

Ford/Siemens Deka 60lb (630cc). 15+ year old design available in ev6 body with uscar connector. Fair spray pattern/mileage and good control. 650-700rwhp rated. Common/good choice still used widely today.

Bosch 65lb (650cc). Newer design, available in ev6 or ev14 body/internal design with uscar connector. Excellent spray pattern for 2v/3v/4v heads. Great control/mileage. 700rwhp rated. Less commonly used injector due to higher price over the SD 60lb.

Bosch/ID/DW 750cc. Newer design, carry over from ls/gm world. Available in ev14 compact (39mm ls) or ev6/ev14 body/internal design with uscar connector. Excellent spray pattern for 2v/3v/4v heads. Great control/mileage. 800rwhp rated. Less commonly used injector due to higher price point.

Ford/Siemens Deka 80lb (875cc). 15+ year old design available in ev6 body with uscar connector. Fair spray pattern/mileage and poor control at low pulse widths requires more fines to tune. 900rwhp rated. Common choice still used today due to cheaper price point compared to other injectors in this size range. I don’t personally recommend them.

Bosch/ID/DW 95lb (1000cc). Newer design, available in ev6 or ev14 body/internal design with uscar connector. DW1000s are for the 2016 Cobrajet. Excellent spray pattern for 2v/3v/4v heads. Available in 4 hole or single ball orifice tip. Excellent control/mileage (single ball orifice tip being optimal). 1000rwhp rated (850rwhp E85). Excellent injector choice for any built motor application up to this power rating.

Bosch 127lb/ID1300 (1330cc). Newer design, carry over from BMW world design. Available in ev6/ev14 body/internal design with uscar connector. Excellent spray pattern for 2v/3v/4v heads. Great control/mileage. 1200rwhp rated (1000rwhp E85). Less commonly used injector due to much higher price point over the 1000cc. Common choice for E85 use due to all stainless steel internals.

Bosch 160lb/ID1700 (1700cc). Modern design, available in ev1, ev6, or ev14 body/internal design with uscar or jetronic connector. Excellent spray pattern for 2v/3v/4v heads. Excellent control/mileage in E85 (fair with gasoline) 1800rwhp rated (1200rwhp E85). Not too commonly used due to similar pricing as the 2000cc.

Bosch 210lb/ID2000 (2225cc). The biggest on the block. Carryover from the import world. Available only in ev14 compact and denso connector so spacers and plug adaptors required for Ford application. Good control/mileage in E85, fair to poor in gas. 2000rwhp+ rated (1600rwhp+ in E85). Controllable up to 100psi base pressure (3350cc). 3700cc max flow rating at 130psi base pressure. $$$$$$$$

E85 Fuel Systems

E85 fuel systems are pretty easy to figure out. They take roughly 25% more fuel than when you’re running on gas. For example, if you have a fuel system that will make 700rwhp on gas, it will be able to support 525rwhp on E85. 700 minus 25% (x .75) equals 525.

If you want to know what injectors/pumps will support E85 at your target power level, simply go to the section above and multiply the horsepower numbers by .75.

End of S&H Fuel section……..Thanks Jeremy!!!

Variable Valve Timing – Lockouts- Limiters

We see a lot of discussion/questions pertaining to cams, variable valve timing (VVT), limiters, and lockouts. This is a bit of a grey area because some of these choices come down to personal preference. Here’s what we think:

The first thing to get out of the way (and you’ll see below) is that we’re not big fans of running aftermarket cams with PD blowers until you’re playing with big power. It’s not because we don’t like cams, we love them. Who doesn’t like the rumpidy, rump, rump of a cam? It’s just that non stock cams on PD blown cars don’t do anything for you until you’re making big power (more on this below). This means that you’re spending money/time on something that doesn’t show up in actual performance. We’re fans of HP/$$$, and cams are a pretty bad value for most PD combinations.

But if you’re going to run cams, here are some things we’ve learned over the years:

Keep the VVT As Long As You Can

If you don’t have to lock out or limit the VVT…………..don’t. Some cams require it (you have to with these), some don’t. The VVT works great, and it really improves midrange torque. And if you have a street car, that’s where you’ll spend most of your time…in the midrange.

Limiters Can Be Scary

We’ve seen TONS of situations where limiters have failed. There are two “styles,” and we’ve seen both of them fail multiple occasions. Yes, some people run them with no problem. But there is a potential problem out there. And it’s not uncommon. If you have cams that require limiters, we suggest simply locking them out.

Lockouts Hurt Torque

There’s no two ways about it. If you can’t affect the valve timing through the VVT, you give up one thing, HP or TQ. Obviously most people choose to give up TQ. Expect to see a 30-40 ft lb loss at about 3000-3500rpm when running lockouts. With PD blowers, this isn’t a huge deal because they already have so much torque. And, in some of the big HP situations, it’s actually an advantage to kill some of that low end. But most people in most situations want that TQ.

High RPMs and Heavy Valve Springs Kill VVT

If you chose a big lumpy cam or you’re even revving the guts out of the stock cams, the VVT starts to show its weaknesses. And sometimes fails. If you’re running heavy valve springs or consistently spinning the motor past 7,000rpms, you want to lock out the cams.

Compression Ratio

This could turn into an article all by itself. There are a lot of factors at play here. We’ll keep this as brief as possible.

In the past couple of years, it has become “fashionable” to run higher and higher compression ratios on boosted motors. There are some reasons for this. But frequently it’s done because it’s the cool new thing to do (not that there’s anything wrong with that).

If you’re going to build a forged motor so you can safely make over 450rwhp, the biggest question you’ll have to answer is “what compression ratio should I make it???”

A quick tutorial on compression ratio and boost

A motor’s compression ratio is how much the air/fuel in the cylinder is squeezed before the spark plug fires. A compression ratio of 10 to 1, commonly written as 10:1, means that, when the piston travels upward in the cylinder, it compresses 10 “units” into 1 “unit” before the combustion cycle (spark plug firing). This compression of air/fuel created pressure (duh!). If this pressure gets too high, the air/fuel will detonate before the spark plug goes off and before the positon gets to the top of its travel. This is called pre ignition or detonation and is BAD. Imagine putting your piston(s) on the workbench and slamming a ball peen hammer into the top of them. That’s what’s happening.

There are a lot of factors that determine when you get detonation. Heat in the block/heads, fuel quality/type/octane rating, cam timing, etc., etc., etc. But assuming everything is working correctly, detonation basically comes down to having too much cylinder pressure. The higher the compression ratio is, the more pressure is created. You want your cylinder pressure to be as high as it can be without detonation. More pressure equals more power.

When you put a blower/turbo on a motor, you’re adding more pressure to the motor “artificially.” So you’re raising your “effective” compression ratio. This puts you closer to the point where you’ll get detonation.

Years ago when fuels weren’t as good/consistent and fuel injection systems weren’t nearly as precise as they are now, you were pretty much forced into running “low” compression ratios with boost to keep from melting motors down due to pre ignition/detonation. Back in 2007, the 5.4L GT500 had an 8.4:1 compression ratio. In 2013, the new 5.8L GT500 motor got a 9.0:1 compression ratio. This is all due to Ford being able to safely fuel/time the 5.8L with the new ECU that was put in that year. It’s much “smarter” than the previous ECU. But 9.0:1 is still “low” by today’s NA standards. The 2005 Mustang GT had a 9.8:1 compression ratio, and the 2011 Mustang Coyote got 11:1 stock.

But people put blowers on the 3v and Coyote and they have “high” compression ratios without detonating them into scrap, don’t they? That’s correct. But the 9.8:1 in the 3v isn’t “that” high. The 11.0:1 in the Coyote, on the other hand, IS high. The Coyote has an advantage with its twin variable cam timing though. Tuners can set them up to bleed boost off through the midrange, where you see most detonation, to control cylinder pressures/detonation. If you couldn’t bleed off the pressure in the Coyote, you wouldn’t be able to run very much boost. 11.0:1 is high for boost and pump gas. Additionally, we (manufacturers and consumers) will do things in the aftermarket that the car manufacturers won’t because they have to warranty it under the assumption that the dumbest person in the world is driving the car, could put crap gas in it, etc.

So Why Do You Want a Higher Compression Ratio for a Boosted Motor?

More Power – More pressure equals more power. But with everything related to motors, there are trade-offs, and limits. There’s a point where you’ll simply have too much compression to run on pump gas (93 octane). Yes, you can run E85 or race fuel and run more compression/boost. But that means you won’t ever be able to run it on gas again unless you drop the boost. Not ideal for most people.

You Can Make a Small Blower Act Like a Big Blower – Depending on what your goals are and how much power you ultimately want to make, the blower you have/choose won’t be big enough. For example, if you have a Roush 2.3L TVS and you want to make 750rwhp, you need high compression. Higher compression will take whatever volume of air the blower can put out and squeeze it even more. Which will make more power. We’re in E85 or race gas territory here though. You can’t get 750rwhp out of almost all of the 3v blowers on pump gas, period. So, if you already own a blower that won’t make the power you want it to and you don’t want to/can’t replace it, bump the compression ratio and run it on E85 or race fuel. “How high can I go?” you ask? Right now it looks like the most people are pushing it to is 12.5:1.

Torque – For turbo or centri setups, a higher compression ratio is nice because the motor will make more torque when not in boost so it will be nicer to drive in real life. A centri or a turbo takes some RPMs before they start to build boost. Punch it at 3,000rpm and you’ll be waiting around a bit for it to start rolling hard/building boost. If you add compression, the power will come in sooner. No amount of compression will get a centri or turbo to act like a PD blower, though. If you punch it with a PD blower, you get full power RIGHT NOW. Yeah, a high compression PD setup will hit sooner/harder than a low compression combo. But realistically that extra torque would probably end up as tire smoke.

IATs – If you have your blower maxed out, this is probably a moot point. And most people are going for high compression because their blower is maxed out. But, if your blower isn’t maxed out and you’re not going to be putting yourself in a position of only being able to run E85 or race fuel, high compression will allow you to reach your power goals at a lower boost level than low compression. And lower boost levels mean lower IATs. How much of an IAT improvement can you expect? We weren’t able to find any concrete data on this anywhere. There are way too many factors that ultimately determine IATs for it to be a simple math problem. One car’s combo could result in wildly different results than another. We can’t imagine the IAT reduction is very much though. And if you’re going high compression/E85, it’s almost irrelevant. E85 has incredible cooling properties. A couple more deg of IAT will get “lost” in the cooling effect of E85.

So Why Don’t You Want a Higher Compression Ratio for a Boosted Motor?

Flexibility – If you go high compression and force yourself into E85 or race fuel, you just turned the car into a “race car.” Most people don’t want to be in this position.

Power/Efficiency – Raising the compression ratio one point (9.0:1 vs 10.0:1 for example) gets you about a 3% increase in power. This extra power is from the air/fuel being squeezed more. More squeeze equals more bang. If you add 1psi of boost, you’ll see a 3.4% increase in power. This is because you’re getting more squeeze (you’re compressing more air). But, more importantly, it’s because you’re getting more air into the cylinder. And more air means once fuel is added you get more bang. In this example, the motor with more boost vs more compression will make .4% more power. That doesn’t sound like much. But it’s more than if you simply bumped the compression. It will almost always be more efficient to add boost opposed to adding compression.

Safety – Your safe tuning window gets narrower the higher the compression ratio goes.

Compression Wrap Up

This section wasn’t put together to answer the question of “what compression ratio should I run?” There are way too many factors, pros/cons, etc. for that to be something that can be answered by someone other than yourself. But we’ll tell you what we’d do in a few situations.

Blower Is Not Big Enough and It Will Always Run on E85 or Race Fuel – In this case, we’d run the compression ratio at 12.5:1.

Blower Is Big Enough for My 600-650rwhp Goal, and I Want to Be Able to Run On Gas (93) and E85 – In this case, we’d run the compression ratio at 9.5-10.0:1.

Blower Is Huge and I Want to Be Able to Run on Gas (93) and E85 – In this case, we’d run the compression ratio at 9.25:1.

One Last “Food for Thought”

These days “What will the blower make?” is becoming more and more irrelevant. As time goes on and blowers get bigger, what the blower can move for air is becoming less and less of an issue. Currently, in some cases, the blowers can move more air than the motors can handle on pump gas (93) without detonation. So the question isn’t what will the blower make, the question is how much power can you make and still remain on 93 octane? In the real world, most people aren’t doing E85 or race fuel setups. So what you have is a fuel limit not a blower limit. Here’s an example that sheds light on that as well as how compression affects power.

If you have a 3v with the stock 9.8:1 compression ratio, you can safely put about 18psi to it (assuming the blower is big enough) and still run on pump gas. It will make 625-650rwhp. These numbers are based on a stock motor with forged rods/pistons, headers and big off road exhaust.

If you have a Coyote with the stock 11.0:1 compression ratio, you can safely put about 10.5-11psi to it and still run on pump gas. It will make 625-650rwhp. These numbers are based on a stock motor with headers and big off road exhaust.

Interesting that both motors make almost identical power when constrained by 93 octane gas, huh? This is because, in both cases, you’re running out of octane, not how much air the blower can move. So, if you’re going to be running on 93 (most people), it really doesn’t matter that much what your compression ratio is. You’re going to ultimately make the same power.

Belt Tensioners

We’re not going to go into a ton of detail here because we already have an entire tech article on belt systems and they’re very, very, complex. To read that article click here: Belt Tensioner Tech

Here is the short version. We have never seen (and we think we have seen them all) a tensioner aside from ours that works correctly. End of story. Nothing out there that we have seen has enough spring pressure, enough travel, or both. And without those two things your belt system will never work right. Oh, you may not chuck belts, but you will be slowly hurting parts (the tech article linked above has that information).

We came up with a very inexpensive solution, the Frankentensioner. It’s $90 and works far better than anything else out there. It’s not pretty though. We could produce pretty ones, but they would be $400+. And frankly a $400+ tensioner is silly for most people.

There are details in the Combinations sections below about stepping up to 8 rib best systems as the power goes up.

Combinations

The Basic 450rwhp Combo

-Cost from stock to 450rwhp – $4,000-6,500

-Cost per horsepower from stock to 450rwhp – $22-37 per HP

The 3v’s stock rods and pistons are good for about 450rwhp and 6,000rpm. After that you’re in the danger zone. They’ll eventually throw a rod out of the motor if you push it much past that. Just ignore people that say they’re good for “XX boost.” Boost isn’t horsepower and RPMs. It may or may not correlate to what power is being made, and it certainly doesn’t correlate to how fast the motor is being spun. To make more than 450rwhp, you need forged rods and pistons, so most people, we estimate 90%, stop there. 450 real deal HP on a street car is a lot of HP despite the internet telling you otherwise. There aren’t many cars in the real world that are faster. That’s 600cc sportbike fast, which is FAST! If you’re not looking for bragging rights on the internet or a specific 1/4mi time, save yourself piles of money, work, and aggravation and stick with 450rwhp.

What do you need to make 450rwhp? Nothing really but a blower kit. You can stick any of the out of the box blower kits (aside from the Roush M90) on your car with no other changes and make an easy 450rwhp. Of course, not many people go straight to the blower (it’s the most cost effective route though) and have some bolt ons. Let’s see how those bolt ons affect a blown combination and the HP they’ll make you at the 450rwhp point.

Exhaust/Off Road X/H Pipe

A cat back system or X/H pipe will make the car sound different (better), but it won’t “make” more power. You’re limited to 450rwhp anyway, which the blower will make all by itself. So exhaust gives you no measureable power advantage.

Headers

Headers will make the car sound different (better), but they won’t “make” more power. You’re limited to 450rwhp anyway, which the blower will make all by itself. So exhaust gives you no measureable performance advantage. Headers can cause some problems though. Depending on where you live, they may not be emission/inspection legal. That’s a huge pain to deal with. If they don’t make power and they’re a pain to deal with, do you want them? A secondary problem and a real one is that headers add a lot of heat to the engine compartment, even the ceramic coated ones. Heat is a very real enemy…you’ll hear us mention heat a LOT. That’s for a reason. In our opinion, all headers should be wrapped with header wrap or ceramic coated then wrapped. Wrapping headers is tedious and, if not done correctly, doesn’t last long. Best bet is to skip headers and save yourself all the problems and the money.

Cold Air Intake

As long as you don’t get a blower kit with a sealed box style airbox (there are a few out there, usually “50 State Legal” kits”), cold air intakes, or “bigger” ones than the one that comes with your blower won’t make one more HP. Skip it.

Throttle Body

A bigger throttle body, you guessed it, won’t make one more HP. Skip it.

Ported Heads

Ported heads, you guessed it, won’t make one more HP. Skip them.

Cams

Cams won’t allow you to make more than 450rwhp either. And, depending on what cams you choose, you’ll hurt torque production down low. We agree good lumpy sounding cams are fantastic to the ears. But considering they’ll make no power or you’ll lose torque, they’re a tough pill to swallow.

Other Supporting Mods at 450rwhp

Well, that’s the big stuff. And it’s all pretty much useless at the 450rwhp level. An argument could be made that, if you were to run a huge cold air intake, huge throttle body, ported heads, cams, headers, and exhaust, you could make 450hp at less boost (this is a whole different subject, just roll with it), which would net you lower intake air temps (another whole different subject, just roll with it). But the drop in boost/intake air temps would never be anywhere close to worth it considering the money involved. You would be much better off spending 25-30% of that money on intercooler system upgrades that will give you much better results for your money.

Summary: 450rwhp

So what do you need to do to make 450hp with your 3v? Put a blower on, that’s it. And it’s that easy. You can spend more money on go-fast widgets, but they won’t do you any good. Take that money and spend it on something that will give you real performance gains. Like cooling mods, suspension mods, wheels/tire mods, brake mods, etc.

All the systems out there (except the Roush M90) will make 450rwhp easily and reliably. The only performance difference that you’ll actually notice is how they control intake air temperatures, which can KILL power if too high. This mainly boils down to intercooler design. In our opinion, choosing a supercharger for the 450rwhp level/application should come down to two things. How well it handles intake air temperatures and cost. Aside from how they look, that’s the only thing that will separate them when in use.

 

The Next Step – 450-575rwhp

Going Straight from Stock to 575rwhp?

-Cost from stock to 575rwhp – $7,225-17,930

-Cost per horsepower from stock to 575rwhp $36-89 per HP

Going from 450 to 575rwhp?

-Cost from 450rwhp to 575rwhp is another $3,225-11,430

-Cost per horsepower from 450 to 575rwhp is another $25-91 per HP

Must Have Mods:

Forged Motor – $2,225-5,000

Above 450rwhp you need to run forged rods and forged pistons. It’s nice to have a forged crankshaft but not actually necessary. A lot of people have made 800+rwhp on stock cranks. Going forged isn’t inexpensive, especially if you’re unable to do your own work. Here’s what forging the bottom end looks like from a cost perspective. For the most part, this is the LEAST expensive way to do it. You could easily spend a lot more money going with better components:

H-Beam rods – $400
Forged pistons/rings – $530
Bearings – $40
Block machining/balancing – $500
Head gaskets – $185
Exhaust gaskets – $26
Main bolts – $50
Head bolts – $90
Billet oil pump gears (a real good idea) – $400

Total – $2,221

This represents the absolute least expensive way this is going to happen. This is if you do all of your own work, you have all the equipment, you have all the tools, etc. And, unless you’re a seasoned mechanic, that probably isn’t going to happen.

-If you can’t build the shortblock yourself, add about $750 for your shop to do it for you.

-If you can’t build your whole motor, add about $1,000 for your shop to do it.

-If you can’t remove/replace your motor yourself, add another $1,000.

You’re looking at $2,225-4,225 for a forged shortblock, depending on your abilities. And this can easily grow by $1,000 going with better components, etc. If you were to walk in a shop and ask for a forged shortblock and have them do all the work, you’re probably looking at a $5,000 bill.

Fuel System – $1,000-1,400

Most blower kits don’t have big enough fuel pumps and fuel injectors to get you up over 500hp. And, if they do, they’ll be on the razors’ edge. So you’re looking at fuel system upgrades (pump and injectors). There are a lot of options here but it’s a pretty safe $1,000. And another $300-400 for installation if you’re not doing it yourself.

Supporting Mods You Really Want:

These aren’t 100% necessary, but they’re pretty close.

8 Rib Belt System – $400-800

The 2005-2010 Mustang GTs come with a 6 rib belt system stock. This system was never meant to run a supercharger, just the accessories. A stock GT500 comes with a 10 rib system…that should tell you something. All of the supercharger kits available (but one) jump the supercharger in to the existing 6 rib system. And if the blower isn’t being spun too hard and your belt tensioner is good, a 6 rib system will work at 450rwhp. But, when you start to spin things up and go for more power, the 6 rib system simply doesn’t cut it, it’s way out of its league. At the 500+hp level, it’s a good time to start thinking about an 8 rib system for the car. An 8 rib system offers 33% more belt, which is significant. Because you don’t need to spin the supercharger real fast at this HP level, you can get away with using a low cost harmonic balancer/lower pulley. It’s actually a stock unit off of an Explorer. An 8 rib conversion will run you about $400. And another $300-400 for installation if you’re not doing it yourself.

Urethane Engine Mounts – $130-230

The stock engine mounts are liquid filled pillowy messes. They were designed for your average Mustang buyer, which you’re not. The problem with the stock mounts is that they flex like crazy. On the dyno you can actually see the motor twisting in the engine compartment quite a bit. This presents two problems. The stock mounts weren’t designed to handle the torque that a blown motor puts out, and eventually they’ll break/pop. Obviously not great. They also allow the motor to move enough while under load for things in the engine compartment to start contacting the engine. The engine can contact the hood, headers can contact all sorts of stuff, etc. And to add insult to injury, when the motor is twisting around like that, it makes the trans hard to shift because it puts a twisting load on the shift linkage. So you really want some urethane mounts. Good thing they’re only about $130. And another $100 for installation if you’re not doing it yourself.

Clutch – $300-1,500

Your stock clutch won’t hold up to this power level. And if it does, it won’t be for long. Budget yourself $300-1,000 for one. And another $400-500 for installation if you’re not doing it yourself.

Intercooler System Upgrades – $300-2,500

More power is made with more boost. More boost means more heat. The intercooler system components that come with supercharger kits out of the box are barely adequate at best. This is standard across the industry. At 450rwhp, it sure doesn’t hurt to run better components. When you start to play with 500rwhp+ you really want a better working system. Well, at least you want to if you want all of your power. There’s a wide range of ways to upgrade these components. You can put a bigger heat exchanger on for $300-1,000 and get better results. You can put a higher flowing water pump on for $300-500 and get better results. Or you can go full bonkers and upgrade the system size from the standard .75″ to 1.25” with a 1.25” heat exchanger, degas tank, lines, and pump for about $2,000. There are lots of ways to go. The good news is that you can get much better performance than what you have (supplied with your kit) for as little as $600. And another $200-500 for installation if you’re not doing it yourself.

As far As Other Supporting Mods, This Is How It Looks:

Cat Back Exhaust

When playing with 450rwhp+ a cat back will give you a couple of HP. Nothing dramatic though. You’ll make your power at slightly less boost though, so that’s not a bad thing.

Off Road X/H Pipe

When playing with 450rwhp+ an off road X/H pipe will give you a couple of HP. Nothing dramatic though. You’ll make your power at slightly less boost though, so that’s not a bad thing.

Headers

When playing with 450rwhp+ headers will give you a couple of HP. Nothing dramatic though. You’ll make your power at slightly less boost though, so that’s not a bad thing.

Cold Air Intake

A bigger CAI certainly won’t hurt. Do you “need” one? No, not really. But a big CAI used in conjunction with a big throttle body will net you a few HP and/or allow you to run the supercharger slower for better intake air temps. You don’t need to go out of your way to use one at this point. But if one drops in your lap, run it.

If your supercharger kit has a sealed box style “airbox” CAI (usually “50 State Legal” kits”) you do want to switch out to one of the “open element” style CAIs. There aren’t very many of the sealed airbox style CAIs out there though, so your chances of running into one are slim.

Throttle Body

Like the big CAI, going with bigger TB than the one that comes with your blower will allow more air into the blower (when combined with a big CAI), which makes the blower’s job easier. Which will net you a few HP. Big CAIs and TBs up at this HP level are not a bad thing to have. Not worth selling a kidney for, but you don’t want to kick one out of bed for eating chips either.

Ported Heads

Ported heads won’t make measurable HP. They’ll drop your boost a little though. But that’s not enough reason to spend $2,000+ on ported heads. We’ve seen 650+hp combos with stock heads, lots of them. Skip them at this point.

Cams

Cams will make more power at this point, sorta-maybe. Cams are tricky and work/don’t work in a lot of different ways. And even if we understood everything about cams, which we don’t, we wouldn’t be able to go over it here.

With some cams you will see a shift in the power curve more than an actual power gain/loss. For example, you may pick up 30hp after 6,000rpm but at the same time you lose 30tq at 3,000rpm. With another cam you may actually see that 30hp gain with no loss of TQ. Then you start throwing the whole limiter/lockout thing at it and your results can be all over the place. We have seen cams that didn’t make power, cams that shifted power and cams that made some power up top with no loss down low. This is something that you need to “gamble” with yourself. We don’t have enough experience in this segment to be the last word.

We’ve been a part of many, many combinations that have made 600+rwhp with stock cams. And they retain mountains of torque. Our “go to” stance on cams at this level is leave them stock. But if you do the research and get good information and you gotta have cams go for it. We love the sound of cams. And we love more HP. We get it. We wouldn’t skimp on other necessary items to stay within a budget though, that’s for sure. You can always put cams in later.

Summary: Other Supporting Mods at 450-575rwhp

Well, that’s the big stuff. And it’s all pretty much useless at the 450-575rwhp level. An argument could be made that if you were to run a huge cold air, huge throttle body, ported heads, cams, headers, and exhaust you could make 450-575hp at less boost (this is a whole different subject, just roll with it), which would net you lower intake air temps (another whole different subject, just roll with it). But the drop in boost/intake air temps would never be anywhere close to worth it considering the money involved. You would be much better off spending 25-30% of that money on intercooler system upgrades that will give you much better results for your money.

Dollar Per Horsepower

You’ll spend $22.85-37.14 per HP to get from the stock 275rwhp to 450rwhp.

You’ll spend ANOTHER $25.80-91.44 per HP to get from 450rwhp to 575rwhp.

If you can do all of your own work and you go entry level on everything, the $$/HP isn’t very bad at all. Just a touch more per dollar than it costs to get from stock to 450rwhp. But at the other end of the spectrum, it’s pricey at $91.44/hp. You’ll probably land somewhere in the middle of that range because you’ll be able to do some things yourself but have to farm other stuff out. Is that HP between 450 and 575 really worth it to you? When it’s broken down like this we’re sure you can see why a lot of people stick with 450rwhp.

What Is Our Suggested 575rwhp Combo?

This is what we would do for a 575hp combo:

-Department Of Boost GT450 Phase I
-Eaton M122 supercharger (stock 07-12’ GT500)
-Stock GT500 throttle body
-Stock 2010+ GT500 CAI

-Forged H beam rods
-Forged pistons (9.5-10.5:1)
-Stock crank (balanced)
-Bearings 
-Block machining/balancing 
-Head gaskets 
-Exhaust gaskets
-Main bolts
-Head bolts 
-Billet oil pump gears

-Stock heads

-FRPP 52lb/hr fuel injectors (stock 13’ GT500)
-FRPP dual “GT500” fuel pump kit

-8 rib belt system
-Urethane engine mounts
-Clutch
-13’ GT500 heat exchanger
-13’ GT500 intercooler water pump

Why This Combo?

This is the least expensive way to make 575rwhp. If you start with a complete blower kit you will at a minimum be upgrading the fuel injectors, fuel pump(s), heat exchanger and water pump. That means you bought them twice. If you build a kit around the GT450 manifold you buy that stuff once. And the GT450 is simply less money to begin with. Most of the blowers will make the 575rwhp. You will just spend more doing it that way.

This is the “coolest” way to do it. The GT450 IC is better than the rest. No matter what you use for a water pump and HE the GT450 will always perform better than the others. And that means more of your power, more of the time.

 

 Things Just Got Real
575-700rwhp

 

Going Straight from Stock to 700rwhp?

-Cost from stock to 700rwhp – $11,355-36,060

-Cost per horsepower from stock to 700rwhp $26-84 per HP

Going from 575 to 700rwhp?

-Cost from 575rwhp to 700rwhp is another – $4,130-18,130

-Cost per horsepower from 575 to 700rwhp is another – $33-145 per HP

 

When you’re looking at over 600rwhp things just got “real”. Despite what the internet tells you there are not very many 3v’s out there making this sort of power. Lots of claims yes, lots of hero runs on the dyno, yes. And lies? Yes, lots of lies. 2013 GT500’s make about 585-600rwhp stock and about 700rwhp with pulleys, big TB, big CAI, injectors, BAP and headers/exhaust. Stock the GT500’s were $65,000ish and to get to 700rwhp those guys are spending another $5,000-8,000. This is “not screwing around” power and it costs real money no matter how you go at it.

Actual 3v’s making this sort of power in real life are few and far between. The main reason is money and effort. But a secondary reason is you’re getting into “race car” territory. And “race cars” are just plain harder to deal with. You’ll not be jumping in, hitting the key, and driving it like a daily driver. It needs more attention, maintenance, etc., etc., etc. If you want this sort of power great!!! Who doesn’t right? But be aware that this sort of power is not “keeping up with the Jones’s,” it’s more than what the Jones’s have. And be aware that you are firmly in the zone of diminishing returns. You’ll spend a lot of money, time, anguish, etc. playing on this particular playing field. And lastly, be aware that some of the superchargers for the 3v can’t make this sort of power. Depending on what supercharger you have you may not be able to make these numbers no matter how much money you throw at it.

Must Have Mods:

Forged Motor – $2,225-5,000

Above 450rwhp you need to run forged rods and forged pistons. It’s nice to have a forged crankshaft, but not actually necessary. A lot of people have made 700+hp on stock cranks. Going forged is not inexpensive, especially if you are unable to do your own work. Here is what forging the bottom end looks like from a cost perspective. For the most part this is the LEAST expensive way to do it. You could easily spend more money going with better components, ARP fasteners, etc.:

H-Beam rods – $400
Forged pistons/rings – $530
Bearings – $40
Block machining/balancing – $500
Head gaskets – $185
Exhaust gaskets – $26
Main bolts – $50
Head bolts – $90
Billet oil pump gears (a real good idea) – $400

Total – $2,221

This represents that absolute least expensive way this is going to happen. This is if you do all of your own work, you have all the equipment, you have all the tools, etc. And unless you’re a seasoned mechanic, that probably isn’t going to happen.

-If you can’t build the shortblock yourself add about $750 for your shop to do it for you.

-If you can’t build your whole motor add about $1,000 for your shop to do it.

-If you can’t remove/replace your motor yourself, add another $1,000.

You’re looking at $2,225-4,225 for a forged shortblock depending on your abilities. And this can easily grow by $1,000 going with better components, etc. If you were to walk in a shop and ask for a forged shortblock and have them do all the work, you’re probably looking at a $5,000 bill.

Fuel System – $1,300-1,700

Not one blower kit has big enough fuel pumps and fuel injectors to get you up to 575rwhp. And nowhere near 700rwhp. So you’re looking at fuel system upgrades. There are a lot of options here, but it’s a pretty safe $1,300. And another $300-400 for installation if you’re not doing it yourself.

8 Rib belt system – $850-1,250

The 2005-2010 Mustang GTs come with a 6 rib belt system stock. This system was never meant to run a supercharger, just the accessories. A stock GT500 comes with a 10 rib system that should tell you something. All of the supercharger kits available jump the supercharger in to the existing 6 rib system. And if the blower isn’t being spun too hard and your belt tensioner is good, a 6 rib system will work at 450rwhp. But, when you start to spin things up and go for more power, the 6 rib system simply doesn’t cut it, it’s way out of its league. At the 500+hp level, it’s a good time to start thinking about an 8 rib system for the car. An 8 rib system offers 33% more belt, which is significant. Another thing is that, at this HP level, you need to spin the blower really fast, and that tales an overdrive (larger) harmonic balancer/lower pulley. Getting an overdrive balancer is a two-fer though. You can spin your blower faster, and you get the engine safety of running a good quality balancer (your motor will thank you). An 8 rib conversion will run you about $850. And another $300-400 for installation if you’re not doing it yourself.

Urethane Engine Mounts – $130-230

You’ll destroy the factory liquid filled engine mounts in short order with this sort of power.

Clutch – $450-1,650

Your stock clutch won’t hold up to this power level. Budget yourself $450-1,000 for one. And another $400-500 for installation if you’re not doing it yourself.

Intercooler System Upgrades – $600-2,500

More power is made with more boost. More boost means more heat. And, at these power levels, you’re looking at quite a bit of boost. The intercooler system components that come with supercharger kits out of the box are barely adequate at 450rwhp/9-10psi. This is standard across the industry. At these power levels you need to make some upgrades if you want all of your power. Even if the car is stone cold when you launch it at the drag strip, you won’t make it through the lights before the intake air temperatures are too high and the ECU starts to pull timing. And that kills power. And that’s perfect conditions. You’ll be pulling timing almost all the time in real life.

There’s a wide range of ways to upgrade these components. You can put a bigger heat exchanger on for $300-1,000 and get better results. You can put a higher flowing water pump on for $300-500 and get better results. Or you can put a bigger heat exchanger and high flow water pump on together and get even better results. You can also go full bonkers and upgrade the system size from the standard .75″ to 1.25” with a 1.25” heat exchanger, 1.25” degas tank, 1.25” lines, and pump for about $2,000. There are lots of ways to go here. The good news is that you can get much better performance than what you have (supplied with your kit) for as little as $600. And another $200-500 for installation if you’re not doing it yourself.

Cat Back Exhaust – $550-1,100

When playing with 575rwhp+ a cat back will give you some power. Somewhere in the neighborhood of 10-20 HP. The stock cat back simply can’t move all the gases that are generated making this sort of power. Additionally, the stock mufflers have been known to “explode” when making big power. This is why you “have” to have one. It will also drop your boost a little bit, which is a good thing, because at these power/boost levels, you’re getting to the point where 93 octane pump gas won’t be enough. Cat back systems run $450-1,000. And another $100 for installation if you’re not doing it yourself.

Off Road X/H Pipe – $250-450

When playing with 575hp+ a, off road X/H pipe will give you a couple of HP. Nothing dramatic though. But, at these HP levels, catalytic converters have been known to come apart, block up the exhaust, and destroy the motor. It’s standard operating procedure to run an off road mid-pipe at these HP levels. It will also drop your boost a little bit, which is a good thing, because at these power/boost levels, you’re getting to the point where 93 octane pump gas won’t be enough. Off road X/H pipes run $150-350. And another $100 for installation if you’re not doing it yourself.

Cold Air Intake – $0-400

None of the CAIs that come with supercharger kits are real happy about making more than 600rwhp. Well, two kits have enough CAI, more on that in the kit review section. Some of them won’t make 600rwhp at all. Inlet restriction to the supercharger is a big deal at these HP levels. You really want a big CAI to reduce inlet restriction. This will allow you to make more boost at the same blower speed and reduces intake air temperatures. With some blower kits you really want one, with other kits you have to have one, and with other kits you can’t actually get bigger ones. Taking into account that you can’t get big CAIs for some supercharger kits, the price range is $0-400.

Throttle Body – $0-800

Like the CAIs, none of the throttle bodies that come with supercharger kits are real happy about making more than 600rwhp. Well, two kits have enough throttle body, more on that in the kit review section. Some of them won’t make 600rwhp at all. Inlet restriction to the supercharger is a big deal at these HP levels. You really want a big throttle body to reduce inlet restriction. This will allow you to make more boost at the same blower speed and reduces intake air temperatures. With some blower kits you really want one, with other kits you have to have one, and with other kits you can’t actually get bigger ones. Taking into account that you can’t get big throttle bodies for some supercharger kits, the price range is $0-800.

Mods You Want, But Don’t Have to Have:

Headers – $0-1,500

When playing with these big power numbers, headers sure don’t hurt. They’ll be worth 10-30hp but, most importantly, they’ll reduce the boost level and make it easier (or possible) to run on 93 octane gas. Because you don’t have to have them, the cost scale starts at $0. Price range $0-1,000. And another $300-500 for installation if you’re not doing it yourself.

Ported Heads – $0-4,100

When playing with these big power numbers, ported heads sure don’t hurt. They’ll be worth 10-30hp but, most importantly, they’ll reduce the boost level and make it easier (or possible) to run on 93 octane gas. Because you don’t have to have them, the cost scale starts at $0. Price range $0-3,600. And another $300-500 for installation if you’re not doing it yourself.

Cams – $0-1,900

Cams will make you any more power at this point, sorta-maybe. Cams are tricky and work/don’t work in a lot of different ways. And even if we understood everything about cams, which we don’t, we wouldn’t be able to go over it here.

With some cams you will see a shift in the power curve more than an actual power gain/loss. For example, you may pick up 30hp after 6,000rpm but at the same time you lose 30tq at 3,000rpm. With another cam you may actually see that 30hp gain with no loss of TQ. Then you start throwing the whole limiter/lockout thing at it and your results can be all over the place. We have seen cams that didn’t make power, cams that shifted power and cams that made some power up top with no loss down low. This is something that you need to “gamble” with yourself. We don’t have enough experience in this segment to be the last word.

We’ve been a part of many, many combinations that have made 600+rwhp with stock cams. But we’re starting to get to the point where you really want to consider them. Certainly at 600+. At this point shifting the power up in the curve is not a bad thing. You will be making MOUNTAINS of torque. Shifting the power up will make the car a lot easier to drive. There aren’t many tires that won’t instantly turn to smoke at this level with stock cams. You will also see a slight decrease in boost, which is a good thing. If you pick the right cam you will see more of a top end charge (more power). There are a lot of good reasons to go for cams at this point. But you don’t NEED them. If your budget is constrained skip them for now and do them later.

Price range $650-1,400. And another $300-500 for installation if you’re not doing it yourself.

Valve Springs – $0-400

If you’re going with cams you will already be getting valve springs. But if you’re retaining the stock cams you still want to consider them. At these boost levels the intake valves can be slightly unseated (open) by the pressure if the valve springs aren’t stiff enough. Add to that you will be spinning more RPM’s (probably) than your average person which will “bounce” the valves if there isn’t enough spring pressure and you have a recipe for power loss. Springs aren’t very expensive and on a build like this not a big deal to add to the list of things to do.

ARP Fasteners (Motor) – $0-550

You don’t have to use ARP fasteners at this power level, the stock fasteners will hold up….barely. They run about $550.

 

Dollar Per Horsepower

You’ll spend $22.85-37.14 per HP to get from the stock 275rwhp to 450rwhp.

You’ll spend ANOTHER $25.80-91.44 per HP to get from 450rwhp to 575rwhp.

You’ll spend ANOTHER $33.04-145.04 per HP to get from 575rwhp to 700rwhp.

The small end of the scale ($33.04) is not entirely representative. That would be for a combination that you’re going to do all the work on and is based on a supercharger that can’t make 700rwhp, and therefore don’t need/can’t use some of the parts/options. That amount is more representative of roughly 600-620rwhp. Playing up at the big end of the scale gets a lot more expensive.

Even if you can do all of your own work and you go entry level on everything, the $$/HP at 650ish rwhp is getting real ugly. You’re looking at about $120/hp. But the top end of the spectrum is getting a little bonkers at $145.04/hp. Is that HP between 575 and 700 really worth it to you? When it’s broken down like this we’re sure you can see why a lot of people stock with 450rwhp. Or even 575rwhp.

And don’t forget, when playing with big power you need all sorts of other supporting car mods. Transmission, driveshaft, rear end, brakes, suspension, etc., etc., etc.

 

What Is Our Suggested 650-700rwhp Combo?

This is representative of what we would do as a minimum for this power level. This will work very well, but everything can be better right? If we were going to throw more money at it, we would spend it on the intercooler system components (heat exchanger, pump, etc.), a return style multi pump fuel system ,and cams.

This is what we would do for a 650-700hp combo:

-Department Of Boost GT450 Phase I
-Eaton 2.3TVS supercharger (stock 13-14’ GT500)
-Cobra Jet or VMP TB
-JLT Big Air CAI

-Forged H beam rods
-Forged pistons (9.25-10.5:1)
-Bearings 
-Block machining/balancing 
-Head gaskets 
-Exhaust gaskets
-ARP Main bolts
-ARP Head studs
-ARP rod bolts 
-Billet oil pump gears

-Stock heads

-1 3/4″ long tube headers
-3” off road X pipe
-3” cat back system

-iD1000 fuel injectors
-FRPP dual “GT500” fuel pump kit
-Boost A Pump

-8 rib belt system w/ OD balancer
-Urethane engine mounts
-Clutch
-13’ GT500 heat exchanger
-13’ GT500 intercooler water pump

Why This Combo?

This is the least expensive way to make 575-700rwhp. If you start with a complete blower kit (assuming it will make this much power, some won’t) you will at a minimum be upgrading the fuel injectors, fuel pump(s), heat exchanger and water pump. And maybe the TB, CAI, MAF, etc. That means you bought those parts twice. If you build a kit around the GT450 manifold you buy that stuff once. And the GT450 is simply less money to begin with.

The 13’ GT500 TVS blower makes the most power out of all of the 2.3L blowers. It was designed last, it makes sense. It’s also relatively inexpensive.

This is the “coolest” way to do it. The GT450 IC is better than the rest. No matter what you use for a water pump and HE the GT450 will always perform better than the others. And that means more of your power, more of the time.

 

Big Big Horsepower E85/Race Fuel Combinations
700rwhp+

This is the point where things go bonkers. You’re pretty much in full race car territory here. We won’t get into specific combinations. There are way too many variables at this point.

At this point, you’re in BIG DOLLAR territory. Especially if you want it to make big power for more than one hit when the car is stone cold. There aren’t many 3v’s on the planet that truly make more than 700rwhp consistently despite it seeming that way on the interwebs. We’d take a wild guess and say it’s maybe 25 cars. If you want to play on this playing field, keep in mind you’re playing with the “Pros.” It’s not easy, it’s not cheap, and there are sacrifices to be made.

Two Major Things Crop Up – Heat and Belts

Heat is always going to be an issue with forced induction. But, up at this level, it’s a major factor. If you want a car that will run a fast 1/4mi time or put down a big number on the dyno, it’s not a huge problem to solve. Especially because you can run an ice chest in these situations. It still needs to be solved though. And, depending on what system you’re running, even with an ice chest, it will still run hot and pull power in as little as 8-9sec. Street or street/strip cars on the other hand need everything and the kitchen sink thrown at them as far as cooling goes if you want to have full power even most of the time. If you want a road course car at this level, get your wallet all the way out. You’ll most likely be looking at custom parts.

Belt systems can be very problematic. There are a lot of factors in if the car will eat belts, have belt slip, etc. If you have relatively high gearing (3.55s for example) and a manual trans, things are going to be rough on the belt. The large RPM drop between gear changes is really tough on the belt. If you have an auto trans and shorter gearing, the belt has a much easier time. But, at the end of the day, it’s just plain tough on belts. All the blowers but one that will make this power jump the blower into the existing belt system. This makes for a very long belt, and long belts stretch a lot. You can go with an 8 rib conversion, which will help. But using the bigger blowers and running them hard on a system with an 8 rib 125”+ belt will never actually work 100% right. You can get them to sorta “live” depending on a lot of factors, but, in most cases, the only reason they’re staying together is that a tensioner is being used that bottoms out hard on its maximum travel stop. This may keep the belt on, but it’s no good for your oil pump gears, crank snout and every bearing in the belt system. You can read more about that situation in our Belt Tech article.

GT500s use a 10 rib belt that’s about 85” long (which stretches a whole lot less than an 8 rib 125”+ belt…..about 45% less), and those guys have belt problems. If you talk to the belt manufacturers, they’ll tell you at this point you need to be running a 12 or 14 rib belt. Do we get away with 10 ribs? Yes, but it’s because we run them a lot tighter than they were designed to. And if a short 10 rib can barely get the job done, a long 8 rib is in for a tough day of work. We’ve seen multiple people that make big power running at the track that go through a belt per run. Belts can be a huge deal.

Dyno Queens don’t see nearly the issues that a drag car does. The dyno is really easy on belts.

What Kind of Combo Do You Want?

People want different things from their cars. Especially at this point. Some people want a car they can drive to/from work every day, cruise on the weekend, etc. Something low maintenance and reliable. Other people may want a car they’re going to trailer to/from the drag strip and are looking for a good 1/4mi time. Another person may be tearing up the twisty back roads or doing track days at the road course. And some people want a big fat dyno number they can post up on Facebook. All of these needs will require a different combination.

Getting this combination right from the start is key to not spending a fortune and doing things 2-5x until you get the performance you want in the environment you want to be in. More people than not fall short of their goals because they don’t know what they’re getting into and eventually their budget kills them. This means there are a lot of cars out there with a pile of go-fast goodies on them that don’t work very well anywhere but the dyno. And sometimes not even there.

The first thing to do is set realistic goals. This is not just a HP goal. This is what you want from your car. You’ll not be very happy if your car makes 900rwhp on the dyno but falls flat on its face when you’re driving it. Or you’re working on it more than driving it. Or it’s just plain not fun to drive.

Once you have your goals set in your head, map out what it takes to get there with help from someone WHO HAS DONE IT BEFORE. Which is about 25 people.

Now figure out how much that costs. Unless you’re one of only a handful of people (we’re not in that handful), you’ll find you don’t have the budget to build an 800rwhp car that will drive around on the street with no problems and make power in situations other than the dyno. It’s going to be a boatload of money. Better to find out now you don’t have the budget before you’re half way in. Not having a budget is what dooms most projects.

If you want advice on reaching goals in this range, drop us an email. We’ll be happy to help you meet your goals on your budget. Or at least get you as close as you can to your goals with the budget you have.

Wrap Up

We hope this is helpful to those of you looking to add boost or add more boost. We, of course, aren’t able to cover absolutely every situation, but this is the broad strokes and will give you a good idea what the playing field really looks like.

In our experience, unreasonable/unattainable expectations are what kills most projects or prevents them from becoming what they were supposed to be.

Modding your car is supposed to be fun, right? Driving you modded car is supposed to be fun, right? Unfortunately a lot of people don’t end up having nearly the fun they thought they would. But they could have with a solid plan based on “realities.” If you stay realistic and have a solid plan, you can have fun, a LOT of fun.

If you have any questions, shoot us an email at departmentofboost@yahoo.com

Thanks!

3v Positive Displacement Supercharger Buyers Guide
WARNING!!!!!

If you don’t want to hear opinions other than your own or hard truths, you like to be recreationally outraged, you’re easily upset, you like your safe spaces, you’re a special snowflake, you’re an unapologetic fanboy of XXXX blower company or you’re simply looking for something to bitch and moan about……………..DON’T GO ANY FURTHER!!

The following article contains mostly facts, but it also contains opinions. Opinions you may not agree with. Enter at your own risk.

Overview—Big Picture

This article needs to be taken with a grain of salt. Let’s be 100% real here. Is there really a bad blower? No, not really. Any blower is better than no blower. It’s like having ANY car is better than having no car at all. What it really comes down to is what will be the best blower for you and your needs. Now, when framed like that, there will be some blowers that ARE NOT good FOR YOU.

If you need a truck to tow your boat to the lake every weekend and you buy a Focus RS………………………you just got a “bad truck.” A Focus RS makes for a crap tow vehicle. It would be like getting a Roush M90 Supercharger to make 1000rwhp. If you did that, you got a “bad” blower. It’s not even close to the right tool for the job.

We have it good these days. We’re truly living in the best time in history to go fast. Never has it been so easy. And we have tons of options. And options are great. But they can also be daunting if we don’t know what best fits our needs. This was written to help you get what best fits your needs. If it’s something we sell, fantastic!!! If it’s not, at least we know we didn’t sell you something that doesn’t work for you. We of course like to make money, but we have to sleep at night, too.

Why We Wrote This

Two reasons:

One – We want to sell more stuff…………duh! We feel that by putting out this hard numbers based buyers guide more people will come to the conclusion that our offerings for the 3v are very good. We had the advantage of designing our options after everyone else had theirs out in the market. This gave us the advantage because the bar had already been set and we could then raise the bar. Additionally, our options in most cases are far less money. Not enough people know how the hard numbers stack up and this gives us the opportunity to get that information out there.

Two – The short answer is someone needed to. We can’t tell you how many times we’ve seen:  “I’m about to buy XXXX blower, I did all my “research,” and this is what I’m getting.” Whoa, whoa, hold on a second there! Research? Where did this person do this “research”?  There’s very, very little real factual information out there to base “research” on. Almost none really. So what are people using for “research” material?

Magazines?

Magazines have zero hard data. And magazines don’t do comparisons or shoot outs anymore. All you’ll find in magazines are puff pieces written FOR manufacturers, vendors, and shops. Do you know why? It’s because they pay to get those articles in there. There are no tests anymore…there’s paid advertising masquerading as information. They do a pretty good job of throwing numbers at you so it seems like you’re learning something. But if you read closely, you’ll find that there’s no hard data or comparisons.

People?

People are a horrible source of information about performance parts. Especially blowers.

Of course they love their blower! As we went over above, any blower is better than no blower. Even the weakest blower that runs way too hot is going to be a whole lot more fun to drive than the car was naturally aspirated. How many people out there have had experience with multiple blowers? We’ll give you a hint…almost none. Who puts two or more different blowers on their car? How many people have a best friend with the same car but with a different blower that they’re allowed to drive hard? Can’t be many, can it? How are “civilians” going to know how well a blower performs if they have no idea where the bar is?

Most people don’t understand the three most important things that make a blower good/bad for a particular person’s needs: Intake air temperature (IAT), belt tensioners/belt systems, and supercharger “size” (displacement). We’re astounded by the percentage of people that don’t understand the importance of the intercooler (IC) design and its effect on IATs. High IATs absolutely murder power. Most people are out driving around up to 100hp down on power almost all the time because of high IATs. Most belt tensioners/belt systems “bottom out” every time they make a full throttle upshift, which eventually hurts parts and can destroy motors. And, lastly, most people don’t understand that a blower’s size doesn’t necessarily translate into the power level they think it does. Additionally, most people don’t understand that bigger is not necessarily better. If the people giving a review on a blower don’t understand the basics, which most don’t, how can their review be worth anything?

From what we’ve seen, the bar is set at “I’ve had my blower for XXXX yrs/miles, the car is fast, and I haven’t had any problems.” What kind of review is that? We know that all the blowers will make the cars considerably faster. And is “I haven’t had any problems” where the bar should be set? That’s like saying “My 1983 Escort with 500,000mi on it is a great car, the wheels haven’t fallen off yet”. A 1983 Escort with 500,000mi on it is crap, wheels or no wheels. The LEAST you can expect from a $6,000ish blower is that it wouldn’t break!!!! We should expect more than the “LEAST,” shouldn’t we?

As humans, we’re flawed and rarely objective when it comes to self-criticism. And a lot of people tie their purchases, especially large purchases, to their own “value.” Most people’s initial reaction to being told that their $6,000 purchase was a mistake is the same one you get if you tell them their new girlfriend used to “party” with the entire hockey team, i.e., not a positive response. That’s not a conscious response, it’s subconscious and human nature. Asking someone their opinion on their latest $6,000 go fast part(s) is going to get you the same response 99.9% of the time. I LOVE IT! Getting an objective opinion from someone is nearly impossible. Over the past ten years, we can count the number of times we’ve seen someone post/say that they WERE NOT happy with their purchase on one hand. Is that because everyone has the right blower for their needs? Nope, not even close.

And lastly, a lot of people, how can this be put delicately……………………drive like pussies. That wasn’t very delicate was it? The fact is that most people drive at their personal skill/experience level. And without training and a lot of seat time the average skill/experience level is way below what cars are capable these days. We get to spend a lot of time with a lot of people in a lot of fast cars. It’s rare that we see someone has the skills/guts/stupidity to run their car at 100%. Most people think they’re driving the guts out of their car. In our estimation most people don’t exceed 75%. And in a lot of cases that’s a good thing. Cars have gotten STUPID fast in the last 15yrs. They can get you into a lot of trouble, real trouble. A little self-preservation is in order. What is the point of all this you ask? It’s this. If the person you’re getting your advice from rarely goes wide open throttle, doesn’t bang hard gear changes, doesn’t use all the RPM’s and doesn’t do back to back runs (That describes a huge portion of the hot rod community) how are they going to have any advice that is worth something to you? We didn’t just say that in an attempt to single anyone out or to make them feel bad. Cars are FAST now. Cars are DANGEROUS now. Not being able to flat foot a 650rwhp car through 5 gears with it trying to loop out on you the entire time is nothing to be ashamed of. That takes a considerable level of skill, training and experience. And the consequences are huge.

Performance Numbers?

How about 1/4mi and dyno numbers, you ask? This could literally take 20 pages if it were covered in detail, and some day we may do that, but for now here’s the short version.

1/4mi times are about useless for a number of reasons. First and foremost is that there are a ton of factors in a 1/4mi time that have nothing to do with the power the car makes. We have a friend with a 2008 Mustang that makes 600rwhp and has run a best of 9.15 in the 1/4mi. It’s a full-tilt boogie drag only car. No street driving ever. Does that mean if you bolt the same blower to your car and make 600rwhp your street car is going to go low 9s? It certainly doesn’t. Without a ton of supporting mods, your street car will be lucky to get into the 11s with 600rwhp. So, unless someone takes a car, let’s say a 2009 GT with 305 drag radials, and makes a pass naturally aspirated and then puts a blower on (only the blower) in the pits and makes another pass that same day, you don’t have a true measure of performance increase. And who does that? Um, no one. You may see where someone ran a 2009 GT last year naturally aspirated and it ran a 12.5. Then this year with a blower it ran a 11.3. That’s a solid 1.2sec drop, right? Well, what was the difference in weather conditions? Does it have the same tires? Exact same suspension? Is it any lighter/heavier? Is the gearing the same? Somewhere in that 1.2 seconds are a ton of variables. Yeah, of course it will go faster with the blower. But how much of it is the blower? And how much of it is other supporting mods? You don’t know. Hell, you could have made that 1.2sec without a blower.

The second problem with 1/4mi times is that most people don’t want to drive a drag car on the street. So what good is a drag car 1/4mi time to you? They have crap brakes. Skinny front tires suck in the real world. Big fat drag radials are wobbly at speed, wear out fast, and suck in the rain. Short gearing gets old on the freeway real fast. Lightweight seats are uncomfortable. Cars with the sound deadener removed are louder in the interior than you want to deal with long term. Good drag-type suspension pieces are loud, clunky, and harsh. The list goes on and on. So if someone says to you “I put XVZ blower on my car, and it runs 10s” but the car is set up toward the drag race end of the spectrum, are you hearing a number that can be run by a car you want to drive every day? Your car with brakes that stop, comfy seats, tolerable gearing, a suspension that will go around corners, tires that will go around corners, a car that won’t kill you in the rain, and a car that doesn’t make so much noise to cause you to lose your mind isn’t going to run 10s with the same power.

The last (at least for this article) issue with 1/4mi performance numbers is that they’re generally attained in perfect conditions. And that means the car is cooled down between runs. For a naturally aspirated car, a cooldown isn’t nearly the factor it is with a blown car. Well, most blown cars. There isn’t a blower kit out of the box that will make two passes back to back without slowing down during the second pass because of high IATs. You don’t get an opportunity to cool your car down when driving around on the street. Once it’s up to temp, it’s up to temp. It already won’t run what that drag car did. Add in some stop lights or a couple of back-to-back runs, and you’re down up to 100hp. So if a drag car running XXX blower that has a crap IC manages some good times at the drag strip, so what? What does that have to do with your street car that you can’t cool between runs? Let’s say that XXX blower with a crap IC runs 10.8 at the drag strip first pass. But if not cooled down, it runs an 11.8 the next pass. Compare that to YYY blower with a good IC that runs 11.0 its first pass at the strip, but runs 11.0 its second pass, and 11.0 its third pass, etc. Which blower is better for your street car?

How about Dyno Numbers?

Oh jeez, dyno numbers. Where to even start? We will be blunt, dyno numbers are bullshit. For starters, you run into the same heat issue that you do with drag passes. A dyno run won’t show IAT issues that you see in real life on the street. Dyno runs are 4-6sec long. And they started with the car cool. And the hood is open. How does that have anything to do with real life?

One dyno can’t be compared to another. It’s even really hard to compare one dyno to itself if you want to get real testing done. You can take the same car to five different dynos on the same day and get five different power readings that can be as much as 75hp apart! Don’t believe us? Check out this article from Hot Rod Magazine.

How about variables? There are literally hundreds of variables when dyno testing. And those variables can add up to a huge swing in power, especially on boosted motors. How are you supposed to compare one dyno “test” to another dyno “test” when they may not have been tested the same way?

And then there’s cheating. It’s incredibly easy to push every factor in your favor on the dyno to show a good number. Factors that you could never control in real life. And then there’s straight up cheating. A few mouse clicks, and you can change considerably the number the dyno shows.

Dynos were designed as a tool to measure changes that were made on one particular car. Preferably on the same day under the exact same conditions. A before and an after. They were never meant to be “raced” against each other. And they certainly weren’t designed to be used as sales tools.

Don’t base your decisions on dyno numbers alone. You’ll be selling yourself short. We’ve seen a ton of cars that ran great on the dyno but fell flat in real life.

The Person Is Selling It to You!

We fully understanding the irony of what we’re about to say, we’re saying it anyway. How can you trust the person selling you your blower? They obviously have an interest in selling what they sell. Or selling what they will make the most money on. Even shops have an interest in selling you the ones they want you to buy. They’ll make more money on some blowers than others. They may not be able to get all of them. They may be faster at installing XXX blower, which means they make more money. We’re not saying that self-interest is a bad thing. Or that it’s going to go away. Completely altruistic people are as rare as unicorns. We’re just saying that it’s a factor in your decision-making process.

Summing Up

We’re not suggesting you take everything we say at face value. Even though we try and be as unbiased as possible, we’re human, too. But, at a minimum, you owe it to yourself to step outside the “box” for a moment and take a look at what you really have to work with when you make your decision to spend money on a blower. For most of us, it’s a LOT of money. And you’re buying in a marketplace that doesn’t guarantee quality. In fact, behind closed doors you’ll hear most people inside the industry say things like “Most of the stuff out there is junk.” That means at best you have a 51% chance of not getting the most out of your blower dollar. Those are shitty odds. The least you can do is actually educate yourself which will make your purchase less a game of chance and more a calculated risk.

Terms and Abbreviations

We use the words supercharger and blower interchangeably. For this write up, they’re the same thing. We’ll be using a lot of abbreviations in this write up. Here’s what they are and what they mean.

CAI – Cold Air Inlet. This is what most people call the assembly that includes everything from the air filter all the way to the throttle body. Some of them aren’t actually “cold air” inlets, they’re hot air inlets. But this is what the community/industry has settled on as the name for it.

Duty Cycle – The Duty Cycle is an expression of how hard a fuel injector or fuel pump is running in comparison to its maximum ability. A 50% duty cycle means that a particular component is running “half way” maxed out.

ECU – Electronic Control Unit. This is your car’s computer. It’s sometimes also referred to as PCM, ECM, etc.

FPDM – Fuel Pump Driver Module. This/these are what “drives” the fuel pumps for the ECU. Think of them as the brains of the fuel pump(s).

HE – Heat Exchanger. The heat exchanger is part of the intercooler system. It’s the “radiator” that mounts up in the nose of the car, and it sheds the heat that’s picked up at the intercooler.

HP – Horsepower.

IAT – Intake Air Temperature. This is the air temperature measured after the intercooler right before it goes into the cylinders. This is very important.

IC – Intercooler. The intercooler is what cools the air coming out of the blower before it enters the cylinders. It’s in the intake manifold, and you can’t see it unless you have the blower off.

lph – Liter Per Hour. This unit of measurement is generally used when describing the abilities of a fuel pump(s).

MAF – Mass Airflow Meter/Sensor.

NA – Naturally Aspirated. A motor with no forced induction (blower or turbo) is naturally aspirated.

OEM – Original Equipment Manufacturer. This means stock. The parts, systems, etc. the car came with.

PD – Positive Displacement. This is the type of supercharger we’re talking about in the write up.

rwhp – Rear Wheel Horsepower. This is the horsepower measured at the wheels on a chassis dyno.

TB – Throttle Body.

TQ – Torque

VVT – Variable Valve Timing

The Guide

The Superchargers

In this article, we’re going to review the positive displacement blowers available for the 3v. These reviews are based on first-hand experience with almost all of them. Some of them we’ve owned, and the rest of them are on friends’ cars that we’ve worked on/driven/played with/tested, etc. One of them we were only able to get information from other people on.

We’re not reviewing the Centrifugal blowers because we don’t have nearly the amount of hands-on experience we’d like to have to feel confident about our opinions.

Some people aren’t going to want to hear what we have to say about “their” blower. Well, too bad. Some of these have really let us down, and you’re going to hear about it. If you’re the type of person that gets all fired up when you hear something negative about your favorite car parts, you might want to stop reading now. Seriously, stop reading. If you get offended from this point on, it’s because you choose to be.

We did our absolute best to remain unbiased. We, of course, sell a couple of these blowers, but not all. So it’s not 100% unbiased. The two kits we produce were designed to specifically outmatch the stuff offered by the other manufacturers in their segment/category. And we got to design them after everything else was already out. They’re going to come off very good in this review, because they were designed to be the best compared to their competition. It’s really that simple. If you think we’re biased and don’t take our review at face value, that’s fine. But you should at least factor in what we have said and not discount it completely. Most of what you’re about to hear are facts that can be measured, not opinions.

Here Are the Main Specifications in the Reviews and What They Mean to You

Price

This is pretty simple. The price of the kit as it’s shipped from the manufacturer. This price is for the base kit that you can make 450-500rwhp with. Not what it will cost you to make the blower’s maximum capable power. You’ll be spending quite a bit more money to stretch some of these superchargers out to their maximum HP levels.

Size/Displacement

The displacement is how much air the supercharger moves through it during each rotation of the screws….in theory. It’s the blower’s “size.” Bigger blowers move more air (most of the time).

Screw Type

There are a couple of different kinds of screws (some people call them rotors). Here’s the extremely condensed breakdown.

Roots Improved – The Roots Improved screws are “old school.” But don’t confuse them with a true Roots setup. Roots stuff is very, very inefficient compared to the newer Roots Improved. Roots Improved is only considered old school in regards to the last 15yrs and when compared to the stuff that has come out since then. Roots Improved are still very good screws. Almost all of the OEMs still use them. They’re by no means “outdated.” Roots Improved screws are a little less efficient than some of the newer stuff. That means that their discharge temps (post blower, pre IC) are going to be slightly higher. They also have slightly more parasitic loss than the newer stuff, which means they take just a little more power to drive at a given boost level. These are all very small points though. One advantage to Roots Improved screws is that they have slightly bigger tolerances, which means that they last a significantly longer time before needing rebuilds. Roots Improved screws are true 100,000mi capable. If you’re driving your car daily, this may be important to you. And this is one very big reason you see the OEMs use them as their stock blowers.

TVS – The TVS (Twin Vortices Supercharger) screws are technically still Roots Improved screws. They’re just a more updated and efficient version. They’re gaining popularity with the OEMs as the “go to” blower for their cars. And they have been pretty big in the aftermarket. They produce a little lower discharge temp per psi of boost and have slightly less parasitic loss than the Roots Improved. They’re also 100,000mi capable.

Twin Screw – The Twin Screw (TS)…..screws are “race” screws. They have much tighter internal clearances and are therefore more efficient than the other two types of screws. They have lower discharge temps per psi of boost and slightly less parasitic loss. But it’s not all upside with a TS blower. Because the clearances are so tight, they need servicing/rebuilds more often. How often? That depends on how fast you’re spinning it. We’ve seen them need rebuilds in as little as 10,000mi and as much as 30,000mi. Rebuilds cost on average $800 plus shipping both directions which can reach $200 easily. You’ll also be looking at 1.5-3 weeks turnaround time. If this is your daily use vehicle, this could be an issue.

Don’t fall into the trap/assumption that a Twin Screw will have lower IATs than a TVS and that they’ll have lower IATs than a Roots Improved. It’s true that the blower discharge temps work like that. But your IATs have a lot more to do with the IC they’re parked on top of. In the blower kits outlined below, there are Twin Screw blowers that have worse IATs than some Roots Improved blowers do.

Screw Manufacturer

This is a company that makes the screws. Some supercharger manufacturers source their screws from another company. They’re put in their own cases and sell them under their name.

Intercooler Water Inlet/Outlet Size

This right here is almost as important as the displacement of the supercharger. The inlet/outlet size of the IC can make or break the IC’s performance. And if you can’t keep things cool, you’ll be down a lot of power when at operating temperature. Intercooler inlet/outlet size directly affects IATs. High IATs are a problem, and they’ll cost you lots of power.

Intercooler Size

Contrary to popular belief, IC size isn’t quite as important as you’d think. The IC’s size is important, and you want as much as you can get. But if your water inlet/outlet is restricted, it doesn’t matter how big your IC is…it won’t perform. IC water port inlet/outlet size will make or break a system by directly impacting how much/fast you can move the water. The IC doesn’t remove the heat, the water running through the IC does. The IC is simply a transfer point for that heat. A big IC will transfer more heat, but if it doesn’t have more water to REMOVE that heat, it’s useless. You can get a “small” IC to work pretty well with enough water flow. But if you have a “big” IC and are flow restricted, there’s nothing you can do, you’re hosed.

Maximum Power

All horsepower levels are rear wheel (rwhp) numbers. The horsepower ratings in this section are real world horsepower on real cars running real 93 octane pump gas (unless noted otherwise) and at full operating temperature. That last one is the key. You will see all sorts of hero runs and claims from people about what power their car made. Well, what it makes stone cold on the dyno vs. up at operating temperature on the street are two completely different things. Some kits deal with real world conditions better than others. This mainly comes down to cooling. The numbers in this section are to be taken as what these kits will make on the same car, same day, same dyno, same conditions. You will, of course, have seen some sort of “flyer” claim about a specific blower that won’t fit in with what’s below. Under the same conditions that “flyer” run was made, the other blower’s power levels would go up or down the same percentage.

There are only four blowers on this list that can’t be run “all out” and remain on pump gas. Our 3v R-Spec, 2013 GT500 2.3L TVS, Kenne Bell 2.8L, and the Kenne Bell 3.2L. These four blowers, when spun up hard, will make more boost than pump gas can deal with. All of the others can be spun to their max RPM without needing race fuel or e85. The e85 maximum HP numbers for the 3v R-Spec, 2013 GT500 2.3L TVS, Kenne Bell 2.8L, and the Kenne Bell 3.2L are called out below as well as their max pump gas numbers.

The HP numbers represented below are the maximum amount that the supercharger head unit can make (how much air it can move). These numbers don’t represent what these kits can make right out of the box. NONE of them will make nearly their maximum power with the supplied fuel injectors, fuel pump(s)/boosters, belt tensioners and, in some cases, best systems, throttle bodies, cold air intakes, etc. The numbers at the high end of the scale can only be accomplished with lots of other supporting mods.

Cold Air Inlet – Blower Inlet/Elbow

The inlet tract before the blower screws (air filter, MAF, TB, blower elbow/inlet) is CRITICAL on PD blowers. The blowers don’t “suck” air through the inlet tract. The only thing moving that air through there is atmospheric pressure. If the inlet tract is too small, you won’t be getting enough air to the blower for it to compress, and, therefore, it will be down on power. The inlet tract can make or break a blower’s performance. We’ve seen a 2013 GT500 2.3L TVS blower make 710rwhp. We’ve also seen a 3.4L Whipple make 640rwhp all maxed out. Both were on very similar 4.6L 3vs. The problem with the 3.4L Whipple was that someone had done a custom install using a Kenne Bell intake manifold that necessitated a custom blower elbow…a really small blower elbow that simply couldn’t move enough air to feed that big 3.4L. If the 3.4L had a correctly sized elbow, it would have made about 1200rwhp at the same blower speed.

Another factor in the inlet tract is what bolt pattern TB it will accept. The GT has a smaller bolt pattern than the GT500. You can get larger than stock GT TBs, but not nearly as large as GT500 TBs come. There are a lot more GT500 TBs to choose from, too. Some of the blower kits use a GT bolt pattern TB and others use a GT500 bolt pattern. One has its own goofy arrangement. If you’re looking for 550rwhp+, someday the size of the TB you can use will become important. As will your options when it comes to MAFs, inlet tubes, etc.

Growth

The “Growth Factor” is how easily the blower kit grows. It’s ability to grow depends on a lot of factors. How restrictive is the inlet? Can it be upgraded/modified? How capable is the IC? Can it be upgraded/modified? How good is the belt system? Can it be upgraded/modified? How much air can the blower ultimately move? Are there a lot, little or no aftermarket upgrade parts available? All of these things are factors in a blower’s ability to grow. If you’re planning on making 450rwhp forever this is not as big of a consideration as if you want to make 450rwhp now and 700rwhp in the future.

Tuning-Tuners

We’re not going to go into what you get for tunes/tuners for each system because, as far as we’re concerned, what you get out of the box, no matter what system it is, is crap. The manufacturers have to send their stuff out with “soft” tunes because they have no idea what variables you have going on with your car. And soft tunes means they are pig rich, don’t have much ignition timing, and the throttle response sucks. Oh yeah, they’ll be down on power compared to a custom tune, too. We think EVERY blower install requires a custom dyno or remote tune.

The Blower Kits

These are in alphabetical order (worked out good for us!). Not order of preference. That’s up to you to decide for yourself. But, just in case you want to know, we rank them below.

 

The kits covered in this guide:

-Department Of Boost GT450 with M122 Supercharger 
-Department Of Boost GT450 with 2.3L TVS Supercharger 
-Department Of Boost 3v R-Spec 
-Edelbrock E-Force Stage 1
-Kenne Bell 2.6L Stage 1
-Kenne Bell 2.6L Stage 2
-Kenne Bell 2.8L and 2.8LC
-Kenne Bell 3.2L LC
-Magnuson MP1900
-Roush M90 
-Roush R2300 Phase 2
-Saleen Series VI 
-Whipple/Ford Racing 2.3L

Department Of Boost GT450 with M122 Supercharger

Price – $3,600 – $4,400
Size/displacement – 2.0L
Screw type – Roots Improved
Screw manufacturer – Eaton
Intercooler inlet/outlet size – .75”
Intercooler size – 202.5cu in
Maximum power on 93 octane – 575rwhp

The GT450 kit was originally designed and targeted to Do It Your Self-ers (DIY) who were looking to make their stock motor’s 450rwhp limit without breaking the bank. For the first year and a half, we didn’t offer anything more than the basic Phase I kit (the manifold). We didn’t start offering complete kits until later. The GT450 has now grown into everything from mild to wild.

The low end of the price range noted above is because a DIY customer can purchase a Phase I kit and then build the rest of their kit by sourcing the remaining parts themselves, which saves money. The high end of the range represents the customer purchasing a Phase III kit, which includes every part needed all in one go.

The 2.0L displacement is a good size for most 3v applications. Especially the 450rwhp range. The Roots Improved screws make a little more heat than the TVS and Twin Screw superchargers. But the IC in the GT450 flows more water than the other kits in the segment, so your net intake air temps with the GT450 are a little better/a push in comparison to the rest of the blowers. Another plus (to some people) is that the GT450 SCREAMS! You’ll think you’re Mad Max with one of these on your car.

The IC ports are above average at .75”. It doesn’t sound that much bigger than the “standard” .625”, but it makes a significant difference to water flow. The GT450 IC flows 40-60% more water depending on which kit you’re comparing to and which pump you’re running. If you decide to run a big heat exchanger and good water pump, you’ll gain significantly more cooling with the GT450 IC opposed to the others in the segment.

The inlet elbow on the supercharger is average. It isn’t a restriction at 450rwhp, but it will be when going for big power. The good news is that the inlet elbow can be ported quite a bit, which will reap rewards. There are also aftermarket/bigger ones available.

The 2.0L M122 blower uses a GT500 bolt pattern TB which makes 450rwhp real easy. If you want to go bigger in the future, there are tons of big GT500 TB options out there. The CAI is also a stock 2010+ GT500 unit. At 100mm, it’s sized very well for 450rwhp. Ford actually uses the same one on the 2013 GT500s that make 595rwhp, so it has plenty of headroom. You can get aftermarket CAIs as big as 156mm for the GT450, so there’s a TON of room to grow there.

The as-delivered 6 rib belt system is average. It works fine at 450rwhp with a good belt tensioner. If big power is the goal, the 6 rib belt system won’t cut it. It can be upgraded to an 8 rib belt system by changing all of the pulleys (in the entire system). This is a pretty good solution and will work for almost all people/situations. We’ve had customers running their GT450 kits with M122 Superchargers VERY HARD, and a good belt tensioner and 8 rib belt conversion get the job done.

There are a lot of advantages to the GT450 kit compared to the rest of the segment:

– It uses mostly Ford OEM parts, so it’s very reliable and easy/inexpensive to get parts for.

– This system grows very well because it uses GT500 parts. Things like big TBs, big cold air kits, big injectors, big heat exchangers, good water pumps, etc., etc., etc. are easy to find and, if found used, are inexpensive. It’s very popular for people to upgrade their Phase III kits right from the start with a big heat exchanger and good water pump.

-If the desire is big horsepower in the future, the GT450 can be upgraded with a 2013 GT500 2.3L TVS. It’s a direct swap (more on this below).

-The billet aluminum manifold is attractive to some. The only billet manifold in the segment.

The disadvantage that sticks out most compared to the other blower kits available is that it’s still a bit more DIY even when the complete Phase III is purchased. It doesn’t quite unpack itself and jump on the car to quite the degree that the other kits do. That said, we would rather install a GT450 than any of the Kenne Bell kits.

When all is said and done, the GT450 is a fantastic choice for the 450rwhp/stock motor buyer. It has all the performance of everything else in the segment but at a lower price.

Department Of Boost GT450 with 2.3L TVS Supercharger

Price – $4,700 – $5,500
Size/displacement – 2.3L
Screw type – TVS
Screw manufacturer – Eaton
Intercooler inlet/outlet size – .75”
Intercooler size – 202.5cu in
Maximum power on 93 octane – 675rwhp

The GT450 kit was originally designed and targeted at Do It Your Self-ers (DIY) who were looking to make their stock motor’s 450hp limit without breaking the bank. But the GT450 can also run the 2013-14 GT500 TVS 2.3L supercharger. We don’t stock/sell the TVS supercharger, so customers can either get a Phase I kit and source the rest of the parts themselves or get a Phase II or III kit minus the M122 that usually comes with them and then add their own TVS that they source themselves.

The low end of the price range noted above is because DIY customers can purchase a Phase I kit and then build the rest of their kit by sourcing the remaining parts themselves, which saves money. The high end of the range is for customers purchasing a Phase III kit, which includes every part needed minus the M122 supercharger, and purchasing a TVS themselves.

The 2.3L displacement is a good size for most 3v applications. The TVS screws are pretty nice. They don’t generate as much heat as a Roots Improved screw but a little more than a Twin Screw. The 2013-14 GT500 TVS has an improved inlet compared to the Roush TVS, so it has the ability to make a little more power. The TVS screws do have that supercharger “scream” that a lot of people like. They’re not necessarily loud, but you’ll know there’s a blower in there.

The IC ports are above average at .75”. It doesn’t sound that much bigger than the “standard” .625”, but it makes a significant difference to water flow. The GT450 IC flows 40-60% more water depending on which kit you’re comparing to and which pump you’re running. If you decide to run a big heat exchanger and good water pump, you’ll gain significantly more cooling with the GT450 IC compared to the others in the segment.

The inlet elbow on the supercharger is quite good. With no modification, it allows the 2013-14 GT500 TVS to make the most power of all the 2.3L superchargers. And the inlet elbow can be ported quite a bit, which will reap even more rewards.

The 2.3L TVS blower uses a GT500 bolt pattern TB which makes 450rwhp real easy. If you want to go bigger in the future, there are tons of big GT500 TB options out there. The CAI is also a stock 2010+ GT500 unit. At 100mm, it’s sized very well for 450rwhp. Ford actually uses the same one on the 2013 GT500s that make 595rwhp, so it has plenty of headroom. You can get aftermarket CAIs as big as 156mm for the GT450, so there’s a TON of room to grow there.

The as-delivered 6 rib belt system is average. It works fine at 450-550rwhp with a good belt tensioner. If more power than 550rwhp is the goal, the 6 rib belt system won’t cut it. It can be upgraded to an 8 rib belt system by changing all of the pulleys (in the entire system). This is a pretty good solution and will work for almost all people/situations. We’ve had customers running their GT450 kits with TVS superchargers VERY HARD, and a good belt tensioner and 8 rib belt conversion get the job done.

There are a lot of advantages to the GT450 kit compared to the rest of the segment:

– It uses mostly Ford OEM parts, so it’s very reliable and easy/inexpensive to get parts for.

– This system grows very well because it uses GT500 parts. Things like big TBs, big cold air kits, big injectors, big heat exchangers, good water pumps, etc., etc., etc. are easy to find and, if found used, are inexpensive.  It’s very popular for people to upgrade their Phase III kits right from the start with a big heat exchanger and good water pump.

-The billet aluminum manifold is attractive to some. It’s the only billet manifold in the segment.

The disadvantage that sticks out most compared to the other blower kits available is that, if you want to run the 2.3L TVS head unit with the GT450, you have to source the TVS yourself. We don’t stock/sell the TVS. We’ll sell you a Phase III (complete kit) minus the blower though if you want to do a TVS head unit but don’t want to build the entire kit. It’s still a DIY kit even when the complete Phase III is purchased though. It doesn’t quite unpack itself and jump on the car to quite the degree that the other kits do. That said, we would rather install a GT450 than any of the Kenne Bell kits.

When all is said and done, the GT450/2.3L TVS combination is a fantastic choice in the segment. It will perform better than its other 2.3L competition because of the improved blower inlet, and it will have lower intake air temperatures because it has the best IC.

Department Of Boost 3v R-Spec

Price – $11,500 – $13,000
Size/displacement – 3.4L – 4.5L
Screw type – Twin Screw
Screw manufacturer – Whipple
Intercooler inlet/outlet size – 1.25”
Intercooler size – 202.5cu in
Maximum power on 93 octane – 775rwhp
Maximum power on e85 – 1200-1400rwhp

The 3v R-Spec was designed to be the most powerful, most technologically advanced, coolest running and reliable kit available for the 3v. It wasn’t designed to be a little better, but to be so much better that second place wasn’t even playing the same game. Nothing was spared, it’s a “no holds barred” design/package. And it’s, of course, expensive.

The 3v R-Spec can be had with a 3.4L, 4.0L, or 4.5L Whipple supercharger depending on your HP goals. Most people go with the 3.4L. The Whipple superchargers are a Twin Screw design.

The 1.25” IC ports (an industry first) are massive compared to everything else out there. This gives the user a huge advantage over other ICs because of its ability to remove so much more heat. The 3v R-Spec IC can remove up to 325% more heat than “standard” ICs. No other blower can touch the R-Spec’s IATs.

The 3v R-Spec has another industry first. A composite heat barrier incorporated into the intake manifold. The heat barrier prevents heat from the cylinder heads that run at about 200deg from transferring to the intake manifold. This allows the IC system to do its primary job of reducing intake air temperatures much better.

The Crusher inlets/elbows on the 3.4-4.5L Whipple superchargers are massive. There’s virtually no restriction on the feed side of the supercharger, which results in not having to run the blower as fast, which translates into more power and lower intake air temperatures.

The R-Spec uses GT500 bolt pattern TBs so you can run the biggest stuff available. Same thing with the CAI. You can go as big as 156mm, which is MASSIVE!!!

The 3v R-Spec comes with a dedicated 10 rib supercharger belt drive system. Only the supercharger is run off of the 10 rib belt. The rest of the accessories remain on the stock 6 rib system. This means bulletproof belt reliability.

Due to the manifold’s design, engine cooling is improved with the 3v R-Spec. Unlike other 3v systems where one bank of cylinders runs hotter than the other, the 3v R-Spec balances water flow for even heat distribution. The internal passages are also larger, which allows for more cooling than any other system available.

Because of packaging reasons, the 3v R-spec comes with a custom alternator. The alternator is 220amps (stock is 135amps) and a much more robust design than the stock alternator that’s consistently problematic. When playing with big HP, you have to run bigger fuel pump(s), bigger IC water pumps, more/bigger fans, etc. All of these items take power to run. The stock alternator is barely able to keep up with the stock power loads. The 3v R-Spec solves this problem right from the start.

The R-Spec grows incredibly well. Because it used mostly GT500 parts, and GT500 stuff gets plain bonkers, there are TONS of big time options. Add that to the fact that you can put a 4.5L blower on and you can make some seriously stuuuupppiiiddd power.

The 3v R-Spec is a beast. It’s by far the most technologically advanced kit on the market for any application. Nothing is even close. If you want to make huge power reliably and have that power all the time, this is the kit for you.

Edelbrock E-Force Stage 1

Price – $6,465
Size/displacement – 2.3L
Screw type – TVS
Screw manufacturer – Eaton
Intercooler inlet/outlet size – .625”
Intercooler size – 120cu in
Maximum power – 590rwhp

The E Force is an interesting piece. Edelbrock went with a different packaging method than most other blower manufacturers. Instead of the norm, which is to have the supercharger “up top” and blowing down into the intake manifold, the E Force has the supercharger down in the valley of the motor, and it blows up into the manifold. In the case of the E Force, the blower and manifold aren’t really even two separate components. It’s all made as one big unit. There’s nothing “wrong” with this approach, but it does limit the size of the IC.

Edelbrock claims that, because they use the “blow up” design and were therefore able to design in longer intake runners, their blower makes more torque than other comparable units. That’s 100% bullpucky. The E Force doesn’t make one more torque than any other comparable blower. Runner length is irrelevant with PD blowers. The science says it doesn’t make more torque, and we’ve seen (first hand) back-to-back testing that shows it doesn’t make more torque.

Because the E Force has the supercharger down in the valley of the motor and the inlet coming straight out of it, the alternator has to be moved from its stock location. Edlebrock supplies the parts needed to do this, but it’s not ideal. Edelbrock has you spinning the alternator backward. This isn’t a problem as far as volt/amp production. But it does cause the alternator’s cooling to suffer because the fans are spinning backward and the alternator itself is backward so whatever air is moving through it is fighting the air coming through the radiator. The stock alternator is already problematic (they fail a lot). Adding more heat and reverse rotation to the alternator is not a fantastic idea. Additionally, the location it’s mounted in makes it much harder to screw with stuff on the front of the motor, change belts, etc.

The 2.3L displacement is a good size for most 3v applications. The TVS screws are pretty nice. They don’t generate as much heat as a Roots Improved screw but a little more than a Twin Screw. The TVS screws do have that supercharger “scream” that a lot of people like. They’re not necessarily loud, but you’ll know there’s a blower in there.

The IC ports are average. They can’t be modified without heavy duty fabrication. The IC size is way below average (about 40% low). It can’t be modified. The IC simply doesn’t have a lot of surface area to transfer heat. At 450hp, it will kinda sorta get the job done if you’re supporting it with a big heat exchanger and good water pump. If you’re going for big power even with a big heat exchanger and good water pump, your IATs will be doomed. We’ve only seen one person who has managed to keep IATs sort of in check when running the blower hard. But that was in a drag car running an ice chest and a big pump. And even with ice, the IATs still weren’t very good.

The inlet tract on the supercharger is small. It’s the main reason that it won’t produce the big HP numbers like some other 2.3L TVS blowers will. The inlet (it’s not really an elbow on this unit) can’t be modified for more flow. The blower comes with its own single bore 85mm TB. That doesn’t give you much headroom to grow. There may be other TBs that can be swapped in (it looks like it may be a GM unit) but, because the inlet directly behind/after it is restricted and can’t be modified, there isn’t any point in using a bigger TB. The CAI/MAF is of average size like the inlet and TB. But, once again, there’s no point in going with a bigger one (we’re not even sure you can) because all of the stuff downstream is restricted anyway.

The as-delivered 6 rib belt system is average. It works fine at 450hp with a good belt tensioner. If big power is the goal, the 6 rib belt system won’t cut it. It can be upgraded to an 8 rib belt system by changing all of the pulleys (in the entire system). This is a pretty good solution and will work for almost all people/situations.

The E Force is packaged very attractively and it comes from a big name company. That’s what drives most of its sales. The problem is that the packaging is the cause of its shortcomings. A classic example of “all show but not as much go.” At 450rwhp, it works fairly well, but it’s not a blower that “grows” well at all. If you’re going to run 450rwhp forever and never go for more, it’s not a horrible choice. But if you think you ever want to go for more power, it’s not what you want.

Kenne Bell 2.6L Stage 1

Price – $5,800
Size/displacement – 2.6L
Screw type – Twin Screw
Screw manufacturer – Kenne Bell
Intercooler inlet/outlet size – .416”
Intercooler size – 170cu in
Maximum power – 595rwhp

We have owned one of the Kenne Bell 2.6s. The Kenne Bell 2.6 was a major disappointment. It was a failure in just about every way imaginable short of locking up. We spent our hard earned money on a Kenne Bell 2.6L, so in this case we put our money where our mouth is.

The 2.6L displacement is above average for a 3v blower. It’s too bad that the extra displacement is useless (more on this below). The Twin Screw screws are nice because they’re the most efficient design. It’s too bad they don’t make a lick of difference as far as performance goes on this supercharger (more on this below). A lot of people really like how the Kenne Bell blowers sound, and they do sound good. More of a woosh than a scream.

The IC is a complete and utter disaster. We’ve never seen a blower kit that handled intake air temperatures as badly. The inlet/outlet ports are only .416”. And, to add insult to injury, you’re forced into using street elbow fittings (the hardest of hard 90deg fittings). And then, once in the manifold, the water has to make another hard 90deg turn (in and out). That’s four hard 90deg turns the water has to make through a .416” orifice. You could hook the IC up to a fire hydrant and it still wouldn’t move enough water. To add insult to injury, the IC is smaller than average, too. The IC ports and IC itself can’t be modified short of major fabrication. We looked at modifying ours and decided that it would be a better use of our time to make an entire manifold and IC from scratch. The intake air temps out of the Kenne Bell 2.6L are nightmarish. At operating temp, you’ll almost never get a run in under full power. And no matter how many big water pumps and heat exchangers you throw at it, you won’t solve the problem. They still run hot even with ice water running through them.

The inlet elbow is also a mess. It’s tiny. It’s the reason that, despite being 2.6L, it can’t flow enough air to make good power. Which means, for any given HP level, you have to spin the Kenne Bell 2.6L faster than superchargers with an efficient free flowing inlet. Aside from scratch building an entire elbow, there’s no modifying it to work better.

The 2.6L uses a GT bolt pattern TB so you’re limited in your choices. In this case it’s irrelevant though. The elbow is so restricted it doesn’t matter what you put on as far as a TB goes. It won’t move air. On the dyno at a blower speed of 18,000rpms (max), we tested the stock GT TB and then a huge twin 66mm unit. It made exactly zero more HP.

This blower kit doesn’t grow very well at all because of all of its restrictions.

The “cold air intake” tube that goes between the TB and the air filter located under the passenger headlight is also a massive inlet restriction. As is the mass airflow meter. The inlet tube and mass air meter are 93mm in diameter. At 450hp, this isn’t a huge deal, but if you want to make big power, it’s a huge problem. To make 600hp, you want the mass airflow meter and inlet tube to be at least 100mm. And that’s still going to be a restriction. You really want to be shooting for 110-127mm in diameter. The problem is that you can’t buy upgraded components for the Kenne Bell 2.6L so you would have to fabricate your own. Which is a huge deal. Additionally, the location where Kenne Bell put the air filter causes some issues. It’s nice that they put the air filter outside of the engine compartment where the air is cooler. The problem is that to get it there you have to cut up the core support and you end up with the inlet tube running right over the top of the engine oil filler/cap, so the tube needs to be removed to put oil in. Additionally, the washer fluid reservoir has to be moved and is replaced by a poopie little “can” supplied by KB that holds about 2 cups of fluid. Not a huge deal, just more items on the list of things that makes owning a Kenne Bell 2.6L tedious.

The as-delivered 6 rib belt system is average. It works fine at 450hp with a good belt tensioner. The problem is that KB has you relocate the ECU down to a spot in front of the tensioner, which prevents you from being able to run the only tensioner we’ve seen that actually works correctly. If big power is the goal, the 6 rib belt system won’t cut it. It can be upgraded to an 8 rib belt system by changing all of the pulleys (in the entire system). For some reason, the Kenne Bell blowers are hard on belt systems though. We suspect it has something to do with the weight of the screws. We’ve seen all sorts of belt issues with Kenne Bell blowers on the 3v. When they start to get spun up in an effort to make big power, issues arise…even with an 8 rib system. If someone is making big power with a Kenne Bell running an 8 rib belt system without apparent problems, the car either has really short gearing, an automatic transmission, it’s slamming the tensioner into its stops on every shift (which isn’t good), or they drive like a wuss. Or any combination of those situations. Because the belt system is so problematic and an 8 rib conversion doesn’t solve it, we designed, made, and sold stand-alone 10 rib systems for Kenne Bell blowers. The first one was designed to solve the belt problems with our car. The 10 rib system works fantastic. But they were $2,000 and we’re not producing them anymore.

Some people like the way the Kenne Bell blowers look. Unfortunately, we think that its good looks get lost in all of the packaging issues. The Kenne Bell blowers are simply the hardest to work with/on. Everything is moved all over the place, and stuff seems like it was put there as an afterthought.

The Kenne Bell 2.6L was a severe disappointment for us. If it wasn’t one thing, it was another. We battled that supercharger for a couple of years before we finally smartened up and sold it. At 450rwhp it’s not horrible, but there are better choices. When going for big power it’s nothing but one problem after another. And it won’t make the power.

Kenne Bell 2.6L Stage 2

Price – $6,300
Size/displacement – 2.6L
Screw type – Twin Screw
Screw manufacturer – Kenne Bell
Intercooler inlet/outlet size – .416”
Intercooler size – 170cu in
Maximum power – 595rwhp

The only difference between the Kenne Bell 2.6L Stage 1 and 2 is that the Stage 2 has a different inlet elbow and it comes with a TB.

We’ve owned one of the Kenne Bell 2.6 Stage 1s that we tested with the Stage 2 inlet elbow and a huge TB. So we’ve “had” the Stage 2 also. The Kenne Bell 2.6 was a major disappointment. It was a failure in just about every way imaginable short of locking up. We spent our hard earned money on a Kenne Bell 2.6L, so, in this case, we literally put our money where our mouth is.

The 2.6L displacement is above average for a 3v blower. It’s too bad that the extra displacement is useless (more on this below). The Twin Screw screws are nice because they’re the most efficient design. It’s too bad they don’t make a lick of difference as far as performance goes on this supercharger (more on this below). A lot of people really like how the Kenne Bell blowers sound, and they do sound good. More of a woosh than a scream.

The IC is a complete and utter disaster. We’ve never seen a blower that handled intake air temperatures as badly. The inlet/outlet ports are only .416”. And to add insult to injury, you’re forced into using street elbow fittings (the hardest of hard 90deg fittings). And then once in the manifold, the water has to make another hard 90deg turn (in and out). That’s four hard 90deg turns the water has to make through a .416” orifice. You could hook the IC up to a fire hydrant, and it still wouldn’t move enough water. To add insult to injury, the IC is smaller than average too. The IC ports and IC itself can’t be modified short of major fabrication. We looked at modifying ours and decided that it would be a better use of our time to make an entire manifold and IC from scratch. The intake air temps out of the Kenne Bell 2.6L are nightmarish. At operating temp, you’ll almost never get a run in under full power. And no matter how many big water pumps and heat exchangers you throw at it, you won’t solve the problem. They still run hot even with ice water running through them.

The Stage 2 inlet elbow is also a mess. It’s tiny. It’s the reason that, despite being 2.6L, it can’t flow enough air to make good power. Which means for any given HP level you have to spin the Kenne Bell 2.6L faster than superchargers with an efficient free flowing inlet. Even though the inlet elbow on the Stage 2 is bigger behind the TB than the Stage 1, it’s the same size right behind the blower, which is what really counts. We tested a Stage 2 inlet elbow on our Stage 1, and it didn’t make one more horsepower. A huge TB made absolutely zero horsepower gain, too. Unless the inlet elbow directly behind the blower case is enlarged, you won’t see any improvement no matter what you do up stream. Aside from scratch building an entire elbow, there’s no modifying it to work better.

The “cold air intake” tube that goes between the TB and the air filter located under the passenger headlight is also a massive inlet restriction. As is the mass airflow meter. The inlet tube and mass air meter are 93mm in diameter. At 450hp this isn’t a huge deal, but if you want to make big power, it’s a huge problem. To make 600hp, you want the mass airflow meter and inlet tube to be at least 100mm. And that’s still going to be a restriction. You really want to be shooting for 110-127mm in diameter. The problem is that you can’t buy upgraded components for the Kenne Bell 2.6L, so you would have to fabricate your own. Which is a huge deal. Additionally, the location where Kenne Bell put the air filter causes some issues. It’s nice that they put the air filter outside of the engine compartment where the air is cooler. The problem is that to get it there you have to cut up the core support, and you end up with the inlet tube running right over the top of the engine oil fill so the tube needs to be removed to put oil in. Additionally, the washer fluid reservoir has to be moved and is replaced by a poopie little “can” supplied by KB that holds about 2 cups of fluid. Not a huge deal, just more items on the list of things that makes owning a Kenne Bell 2.6L tedious.

It comes with a HUGE GT500 bolt pattern twin 75mm TB, which is a nice bonus.

This blower kit doesn’t grow very well at all because of all of its restrictions.

The as-delivered 6 rib belt system is average. It works fine at 450hp with a good belt tensioner. The problem is that Kenne Bell has you relocate the ECU down to a spot in front of the tensioner, which prevents you from being able to run the only tensioner we’ve seen that actually works correctly.  If big power is the goal, the 6 rib belt system won’t cut it. It can be upgraded to an 8 rib belt system by changing all the pulleys (in the entire system). For some reason, the Kenne Bell blowers are hard on belt systems. We suspect it has something to do with the weight of the screws. We’ve seen all sorts of belt issues with Kenne Bell blowers on the 3v. When they start to get spun up in an effort to make big power, issues arise, even with an 8 rib system. If someone is making big power with a Kenne Bell running an 8 rib belt system without apparent problems, the car either has really short gearing, an automatic transmission, it’s slamming the tensioner into its stops on every shift (which isn’t good), or they drive like a wuss. Or any combination of those situations. Because the belt system is so problematic and an 8 rib conversion doesn’t solve it, we designed, made, and sold stand-alone 10 rib systems for Kenne Bell blowers. The first one was designed to solve the belt problems with our car. The 10 rib system woks fantastic. But they’re $2,000, and we’re not producing them anymore.

Some people like the way the Kenne Bell blowers look. Unfortunately for us, we think that its good looks get lost in all of the packaging issues. The Kenne Bell blowers are simply the hardest to work with/on. Everything is moved all over the place, and stuff seems like it was put there as an afterthought.

The Kenne Bell 2.6L Stage 2 (Well, a Stage 1 with the Stage 2 elbow) was a severe disappointment for us. If it wasn’t one thing, it was another. We battled that supercharger for a couple of years before we finally smartened up and sold it. At 450rwhp, it’s not horrible, but there are better choices. When going for big power, it’s nothing but one problem after another.

Kenne Bell 2.8L and 2.8LC

Price – $6,300
Size/displacement – 2.8L
Screw type – Twin Screw
Screw manufacturer – Kenne Bell
Intercooler inlet/outlet size – .416”
Intercooler size – 170cu in
Maximum power on 93 octane – 685rwhp
Maximum power on e85 – 850rwhp

The only difference between the Kenne Bell 2.8L and the Kenne Bell 2.6L kits is the head unit (the supercharger), supercharger inlet elbow, the “cold air” inlet tube, and the mass airflow sensor/air filter.

We’ve owned one of the Kenne Bell 2.6 Stage 1s. And a really good friend whose car we used for a lot of testing owned the 2.8L. We’ve had a lot of hands-on experience with the Kenne Bell superchargers for the 3v.

The first thing to get out of the way is the “Liquid Cooled Supercharger,” (which is an option on the 2.8L). This “feature” is not what it appears to be. Kenne Bell has not lied about what it does. But they let the customer base think that it’s something it’s not. A majority of the customer base thinks that the supercharger is liquid cooled and that cooling somehow affects the intake air temperatures. That’s 100% false. The only liquid cooled part of the supercharger is the aluminum plate that the front rotor bearings sit in. Kenne Bell was having issues with the larger displacement superchargers crashing the rotors into each other because of heat expansion. Obviously crashing the rotors into each other is bad. Instead of redesigning the supercharger case to prevent the rotors from crashing into each other (a major expense), they added liquid cooling to the front bearing plate where heat/expansion is at its highest. The liquid cooling isn’t a performance “feature.” It’s a band aid for a core design problem.

The 2.8L displacement is above average for a 3v blower. The Twin Screw screws are nice because they’re the most efficient design. A lot of people really like how the Kenne Bell blowers sound, and they do sound good. More of a woosh than a scream.

The IC is a complete and utter disaster. It’s the same IC that isn’t good enough for the 2.6L unit. It performs even worse with the 2.8L. We’ve never seen a blower that handled intake air temperatures as badly. The inlet/outlet ports are only .416”. And, to add insult to injury, you’re forced into using street elbow fittings (the hardest of hard 90deg fittings). And then, once in the manifold, the water has to make another hard 90deg turn (in and out). That’s four hard 90deg turns the water has to make through a .416” orifice. You could hook the IC up to a fire hydrant, and it still wouldn’t move enough water. To add more insult to injury, the IC is smaller than average, too. The IC ports and IC itself can’t be modified short of major fabrication. We looked at modifying the one on our 2.6L and decided that it would be a better use of our time to make an entire manifold and IC from scratch. The intake air temps out of the Kenne Bell 2.8L are nightmarish. At operating temp, you’ll almost never get a run in under full power. And no matter how many big water pumps and heat exchangers you throw at it, you won’t solve the problem. They still run hot even with ice water running through them.

The inlet elbow is a huge improvement over the two Kenne Bell 2.6L superchargers. It’s MASSIVE in comparison and that really helps the 2.8L to ingest all the air it needs to behave like a 2.8L.

The “cold air intake” tube that goes between the TB and the air filter located under the passenger headlight is 114.3mm, which is pretty big. The mass airflow meter and air filter are also 114.3mm…a massive improvement over the Kenne Bell 2.6L superchargers. It’s nice that they put the air filter outside of the engine compartment where the air is cooler. The problem is that to get it there you have to cut up the core support.

It comes with a HUGE GT500 bolt pattern twin 75mm TB, which is a nice bonus.

This kit doesn’t grow very well because the inlet side is impossible to open up more short of major fabrication. The plus side is that the inlet side of things is quite good and the HP potential of the blower is pretty high as delivered. So it’s pretty much irrelevant.

The as-delivered 6 rib belt system is average. It works fine at 450hp with a good belt tensioner. The problem is that KB has you relocate the ECU down to a spot in front of the tensioner, which prevents you from being able to run the only tensioner we’ve seen that actually works correctly.  If big power is the goal, the 6 rib belt system won’t cut it. It can be upgraded to an 8 rib belt system by changing all of the pulleys (in the entire system). For some reason, the Kenne Bell blowers are hard on belt systems. We suspect it has something to do with the weight of the screws. We’ve seen all sorts of belt issues with Kenne Bell blowers on the 3v. When they start to get spun up in an effort to make big power, issues arise, even with an 8 rib system. If someone is making big power with a Kenne Bell running an 8 rib belt system without apparent problems, the car either has really short gearing, an automatic transmission, it’s slamming the tensioner into its stops on every shift (which isn’t good), or they drive like a wuss. Or any combination of those situations. Because the belt system is so problematic and an 8 rib conversion doesn’t solve it, we designed, made, and sold stand-alone 10 rib systems for Kenne Bell blowers. The first one was designed to solve the belt problems with our car. The 10 rib system woks fantastic. But they’re $2,000 and we’re not producing them anymore.

The Kenne Bell 2.8L is a huge improvement over the 2.6L unit. It will stomp out some big horsepower numbers if you can keep belts on it and it stays cool enough. It makes really good dyno runs where the belt system isn’t nearly as stressed, and the IC isn’t loaded hard. It runs fairly well at the drag strip, too, where the belt system isn’t as stressed as it is on the street because the drag cars usually have shorter gearing and automatic transmissions…which are much easier on belt systems. And, at the drag strip, the car can be cooled down considerably between runs, so the IC deficiencies are masked slightly. A lot of drag racers run ice chests for the IC, which is a big help, too. Additionally, e85 will mask intake air temperature problems to a degree.

Some people like the way the Kenne Bell blowers look. Unfortunately, for us, we think that its good looks get lost in all of the packaging issues. The Kenne Bell blowers are simply the hardest to work with/on. Everything is moved all over the place, and stuff seems like it was put there as an afterthought.

If what’s most important to you is a blower that will show you big numbers on the dyno and, if conditions are just right, put up a good number at the drag strip, the Kenne Bell 2.8L is a good choice. But if you want to be able to pound on it without having belt problems, make the same power on the street as you did on the dyno, and be able to make two passes back to back without the car slowing down, you want to look somewhere else.

Kenne Bell 3.2L LC

Price – $6,500
Size/displacement – 3.2L
Screw type – Twin Screw
Screw manufacturer – Kenne Bell
Intercooler inlet/outlet size – .416”
Intercooler size – 170cu in
Maximum power on 93 octane – 725rwhp
Maximum power on e85 – 1100rwhp

The only difference between the Kenne Bell 3.2L and the Kenne Bell 2.8L kit is the head unit (the supercharger).

We’ve owned one of the Kenne Bell 2.6 Stage 1s. And a really good friend whose car we used for a lot of testing owned the 2.8L. We’ve had a lot of hands-on experience with the Kenne Bell superchargers for the 3v.

The first thing to get out of the way is the “Liquid Cooled Supercharger.” This “feature” isn’t what it appears to be. Kenne Bell hasn’t lied about what it does. But they let the customer base think that it’s something it’s not. A majority of the customer base thinks that the supercharger is liquid cooled and that cooling somehow affects the intake air temperatures. That’s 100% false. The only liquid cooled part of the supercharger is the aluminum plate that the front rotor bearings sit in. Kenne Bell was having issues with the larger displacement superchargers crashing the rotors into each other because of expansion. Obviously crashing the rotors into each other is bad. Instead of redesigning the supercharger case to prevent the rotors from crashing into each other (a major expense) they added liquid cooling to the front bearing plate where heat/expansion is at its highest. The liquid cooling is not a performance “feature.” It’s a band aid for a design problem.

The second thing to get out of the way is that the 3.2L supercharger has had some problems with the rotors crashing into each other when spun real hard. Despite being liquid cooled. We know of one shop that had this happen to five cars. We don’t know what was done to rectify this problem because, when this was written, no permanent solution has been found that we know of.

The 3.2L displacement is way above average for a 3v blower. The Twin Screw screws are nice because they’re the most efficient design. A lot of people really like how the Kenne Bell blowers sound, and they do sound good. More of a woosh than a scream.

The IC is a complete and utter disaster. It’s the same IC that isn’t good enough for the 2.6L and the 2.8L units. It performs even worse with the 3.2L. We’ve never seen a blower kit that handled intake air temperatures as badly. The inlet/outlet ports are only .416”. And to add insult to injury, you’re forced into using street elbow fittings (the hardest of hard 90deg fittings). And then, once in the manifold, the water has to make another hard 90deg turn (in and out). That’s four hard 90deg turns the water has to make through a .416” orifice. You could hook the IC up to a fire hydrant, and it still wouldn’t move enough water. To add insult to injury, the IC is smaller than average, too. The IC ports and IC itself can’t be modified short of major fabrication. We looked at modifying the one on our 2.6L and decided that it would be a better use of our time to make an entire manifold and IC from scratch. The intake air temps out of the Kenne Bell 3.2L are nightmarish. At operating temp, you’ll almost never get a run in under full power. And no matter how many big water pumps and heat exchangers you throw at it, you won’t solve the problem. They still run hot even with ice water running through them.

The inlet elbow is a huge improvement over the two Kenne Bell 2.6L superchargers. It’s MASSIVE in comparison and that really helps the 3.2L to ingest all the air it needs to behave like a 3.2L.

The “cold air intake” tube that goes between the TB and the air filter located under the passenger headlight is 114.3mm, which is pretty big. The mass airflow meter and air filter are also 114.3mm. A massive improvement over the Kenne Bell 2.6L superchargers. It really does need to be bigger though to support the 3.2L. And, unless you custom make one, they’re unavailable. It’s nice that they put the air filter outside of the engine compartment where the air is cooler. The problem is that to get it there you have to cut up the core support.

It comes with a HUGE GT500 bolt pattern twin 75mm TB, which is a nice bonus.

This kit doesn’t grow very well because the inlet side is impossible to open up more short of major fabrication. The plus side is that the inlet side of things is quite good and the HP potential of the blower is pretty high as delivered. So it’s pretty much irrelevant.

The as-delivered 6 rib belt system is average. It works fine at 450hp with a good belt tensioner. The problem is that Kenne Bell has you relocate the ECU down to a spot in front of the tensioner, which prevents you from being able to run the only tensioner we’ve seen that actually works correctly. If big power is the goal, the 6 rib belt system won’t cut it. It can be upgraded to an 8 rib belt system by changing all of the pulleys (in the entire system). For some reason, the Kenne Bell blowers are hard on belt systems. We suspect it has something to do with the weight of the screws. We’ve seen all sorts of belt issues with Kenne Bell blowers on the 3v. When they start to get spun up in an effort to make big power, issues arise, even with an 8 rib system. If someone is making big power with a Kenne Bell running an 8 rib belt system without apparent problems, the car either has really short gearing, an automatic transmission, it’s slamming the tensioner into its stops on every shift (which isn’t good), or they drive like a wuss. Or any combination of those situations. Because the belt system is so problematic and an 8 rib conversion doesn’t solve it, we designed, made, and sold stand-alone 10 rib systems for Kenne Bell blowers. The first one was designed to solve the belt problems with our 2.6L car. The 10 rib system woks fantastic. But they’re $2,000, and we’re not producing them anymore.

The Kenne Bell 3.2L is a huge improvement over the 2.6L units. It will stomp out some big horsepower numbers if you can keep belts on it and it stays cool enough. They make really good dyno runs where the belt system isn’t nearly as stressed, and the IC isn’t loaded as hard. They also run fairly well at the drag strip because the belt system isn’t as stressed as it is on the street because the drag cars usually have shorter gearing and automatic transmissions. Which are much easier on belt systems. And, at the drag strip, the car can be cooled down considerably between runs, so the IC deficiencies are masked slightly. A lot of drag racers run ice chests for the IC, which is a big help, too. Additionally, e85 will mask intake air temperature problems to a degree.

Some people like the way the Kenne Bell blowers look. Unfortunately, for us, we think that its good looks get lost in all of the packaging issues. The Kenne Bell blowers are simply the hardest to work with/on. Everything is moved all over the place, and stuff seems like it was put there as an afterthought.

If what’s most important to you is a blower that will show you big numbers on the dyno and if conditions are just right put up a good number at the drag strip, the Kenne Bell 3.2L is a good choice. But if you want to be able to pound on it without having belt problems, make the same power on the street as you did on the dyno, and be able to make two passes back to back without the car slowing down, you want to look somewhere else.

Magnuson MP1900

Right off the start we should say that we have the least amount of experience with the Magnacharger. Not much is first hand. This is information we dug up from people we know that have them and checked against what we could find on the net. Some of these hard numbers can be a couple of percent off.

Price – $5,490
Size/displacement – 1.9L
Screw type – TVS
Screw manufacturer – Eaton
Intercooler inlet/outlet size – .625”
Intercooler size – 120 cu in (estimated). It’s small. They run hot. That’s a fact.
Maximum power – 590rwhp

The 1.9L displacement is a bit on the small side for 3v applications. But it acts like a bigger blower because of its very efficient inlet. The TVS screws are pretty nice. They don’t generate as much heat as a Roots Improved screw but a little more than a Twin Screw. The TVS screws do have that supercharger “scream” that a lot of people like. They’re not necessarily loud, but you’ll know there’s a blower in there.

The IC ports and size are average. They can’t be modified without heavy duty fabrication. The IC itself is quite small. We’ve never been able to put a tape measure on one but we’re guessing it’s 120 cu in.  At 450rwhp it will get the job done if you’re supporting it with a big heat exchanger and good water pump. If you’re going for big power even with a big heat exchanger and good water pump, you’ll have high IAT issues and won’t be able to get much full throttle time out of it before it pulls timing and kills power.

There is no “inlet elbow” on the blower. The TB bolts directly to the blower and the inlet side of the screws are right on the other side of that. It’s the most efficient inlet design you will see. This inlet arrangement allows it’s 1.9L to act bigger. The blower uses a GT bolt pattern TB so your choices of how big you can go are limited. The CAI/MAF is average size and will support up to 550rwhp without much trouble. After that it becomes a restriction. As far as we know there are no large aftermarket CAI’s available.

The as-delivered 6 rib belt system is average. It works fine at 450rwhp with a good belt tensioner. If big power is the goal, the 6 rib belt system won’t cut it. It can be upgraded to an 8 rib belt system by changing all of the pulleys (in the entire system). This is a pretty good solution and will work for almost all people/situations.

The one “goofy” thing about the MP1900 is that to run the inlet on the front the blower needs to be driven off the back. This means that there is a jack shaft that runs to the back of the blower and that in turn spins the blower. The problem is that Magnacharger went with a belt back there and it has been known to be problematic. We know people that are constantly messing with it because of belt slip issues.

The Magnacharger has pretty good packaging. Fit and finish is average. The front entry is great. But it’s let down by the underperforming intercooler, small-ish size and rear belt issues.

 

Roush M90

Price – $4,976
Size/displacement – 1.6L
Screw type – Roots Improved
Screw manufacturer – Eaton
Intercooler inlet/outlet size – .625”
Intercooler size – Hard data unavailable. They run hot. That’s a fact.
Maximum power – 410rwhp

The Roush M90 came on a lot of Roush cars that were sold through dealers. They sell the superchargers separately, too. The blower is way too small for a 4.6L V-8. The screws were originally designed for a 3.8L V-6 motor. It’s the wrong size for the job…it’s as simple as that. It won’t even make 450rwhp spinning at its maximum RPM without all sorts of high dollar supporting gear. And, because it’s spinning at its maximum RPM even in an entry level application, it makes a lot of heat. Add to that an average IC design and you have yourself a blower that runs like a dog almost all the time. Unless you’re getting one for next to “free,” avoid it at all costs. The one plus to some people is that the M90 blower noise is a SCREAM! You’ll think you’re Mad Max with one of these on your car.

 

Roush R2300 Phase 2

Price – $6,580
Size/displacement – 2.3L
Screw type – TVS
Screw manufacturer – Eaton
Intercooler inlet/outlet size – .625”
Intercooler size – 180cu in
Maximum power – 645rwhp

The Roush R2300 came on some of the higher end Roush cars that were sold through dealers. They sell the superchargers separately, too.

The 2.3L displacement is a good size for most 3v applications. The TVS screws are pretty nice. They don’t generate as much heat as a Roots Improved screw but a little more than a Twin Screw. The TVS screws do have that supercharger “scream” that a lot of people like. They’re not necessarily loud, but you’ll know there’s a blower in there.

The IC ports and size are average. They can’t be modified without heavy duty fabrication. At 450rwhp it will get the job done if you’re supporting it with a big heat exchanger and good water pump. If you’re going for big power even with a big heat exchanger and good water pump, you’ll have high IAT issues and won’t be able to get much full throttle time out of it before it pulls timing and kills power.

The inlet elbow on the supercharger is average. It isn’t a restriction at 450rwhp, but it will be when going for big power. The good news is that the inlet elbow can be ported quite a bit, which will reap rewards. The blower uses a GT500 bolt pattern TB so you can go really big and you have lots of choices. The CAI/MAF is average size and will support up to 550rwhp without much trouble. There are aftermarket solutions to go bigger though. This kit has decent growth potential.

The as-delivered 6 rib belt system is average. It works fine at 450rwhp with a good belt tensioner. If big power is the goal, the 6 rib belt system won’t cut it. It can be upgraded to an 8 rib belt system by changing all of the pulleys (in the entire system). This is a pretty good solution and will work for almost all people/situations. Roush also offers a FEAD system for the R2300, which separates the blower belt (so you end up running two belts) from the accessory system. This is also a good solution.

The Roush has fantastic fit and finish. It’s nearly “stock” in the sense that it looks like it was designed by Ford to be stock on the car. It’s of good quality and has no bugs in the system.

 

Saleen Series VI

Price – No longer available
Size/displacement – 2.3L
Screw type – Twin Screw
Screw manufacturer – Lyshom
Intercooler inlet/outlet size – .625”
Intercooler size – 160cu in
Maximum power on 93 octane – 640rwhp

The Saleen is an interesting piece. They went with a different packaging method than the other blower manufacturers. Instead of the norm, which is to have the supercharger “up top” and blowing down into the intake manifold, the Saleen has the supercharger down in the valley of the motor, and it blows up into the manifold. But, unlike the E Force, the inlet is still “up top.” They actually kept the TB in roughly the stock non-supercharged location. In the case of the Saleen, the blower and manifold aren’t really even two separate components. It’s all made as one big unit. There’s nothing “wrong” with this approach, but it does limit the size of the IC, and the inlet is a little goofy. It works, the HP numbers support that. It’s just different.

Unlike Edlebrock, Saleen never made the false claim that the “upside down” designs runner length made more torque.

Because the Saleen has the supercharger down in the valley of the motor, the alternator has to be moved from its stock location. Saleen supplies the parts needed to do this, but it’s not ideal. Saleen has you spinning the alternator backward. This isn’t a problem as far as volt/amp production. But it does cause the alternator’s cooling to suffer because the fans are spinning backward and the alternator itself is backward so whatever air is moving through it is fighting the air coming through the radiator. The stock alternator is already problematic (it fails a lot). Adding more heat and reverse rotation to the alternator isn’t a fantastic idea. Also, the location it’s mounted in makes it much harder to screw with stuff on the front of the motor, change belts, etc.

The 2.3L displacement is a good size for most 3v applications. The Twin Screw screws are pretty nice. They don’t generate as much heat as a Roots Improved or the TVS screws do. The Saleen is one of the quieter blowers out there. All spun up and making max power it makes noise, just not a ton of it.

The IC ports are average. They can’t be modified without heavy duty fabrication. The IC ports can be modified to be larger, but it’s pretty involved/takes real machining operations. The IC size is way below average (about 35% low). The IC simply doesn’t have a lot of surface area to transfer heat. At 450rwhp, it will kinda sorta get the job done if you’re supporting it with a big heat exchanger and good water pump. If you’re going for big power even with a big heat exchanger and good water pump, your IATs are doomed.

The inlet on the supercharger is kinda……different. But it gets the job done pretty well. It can be slightly modded to flow more, but not a lot.

The Saleen uses GT bolt pattern TBs, so you’re more limited in your choices.

The as-delivered 6 rib belt system is average. It works fine at 450rwhp with a good belt tensioner. If big power is the goal, the 6 rib belt system won’t cut it. It can be upgraded to an 8 rib belt system by changing all of the pulleys (in the entire system). This is a pretty good solution and will work for almost all people/situations.

The Saleen is packaged very attractively and the Saleen name is “famous.” That’s what drove most of its sales. At 450rwhp, it works pretty well, and it “grows” fairly well. If you’re going to run 450rwhp forever and never go for more, it’s a pretty good unit. But if you want to play up and above 550rwhp, there are better choices that will stay cooler.

 

Whipple/Ford Racing 2.3L

Price – $6,580
Size/displacement – 2.3L
Screw type – Twin Screw
Screw manufacturer – Whipple
Intercooler inlet/outlet size – .625”
Intercooler size – 180cu in
Maximum power – 645rwhp

Ford Racing sold the Whipple 2.3L kit under the Ford Racing name. They’re the same kit.

The 2.3L displacement is a good size for most 3v applications. The Twin Screw screws are pretty nice. They don’t generate as much heat as a Roots Improved or the TVS screws do. The Whipple does make some noise. Like most Twin Screw blowers, it’s a woosh more than a scream.

The IC ports and size are average. They can be modified, but it takes a milling machine to do it. That said, it’s a pretty easy mod. We’ve opened these up to accept .75” fittings, which is a big improvement over the as-delivered .625”. At 450rwhp, it will get the job done if you’re supporting it with a big heat exchanger and good water pump. If you’re going for big power, even with a big heat exchanger and good water pump you’ll have high IAT issues and won’t be able to get much full throttle time out of it before it pulls timing and kills power. But, with the ports opened up, it will get you much better results. The best non-Department Of Boost results you can get.

The inlet elbow on the supercharger is average. It isn’t a restriction at 450rwhp, but it will be when going for big power. The good news is that the inlet elbow can be ported quite a bit, which will reap rewards. It can also be modified to accept a GT500 bolt pattern TB which gives you a lot more choices, and you can go quite a bit bigger. It does take some work, but it could be done with a Dremel and a drill. A real die grinder and a drill press is the way to do it though.

The “Cold Air Kit” is specific to the kit and not sized very well. It works fine up to about 550rwhp but after that becomes a restriction. Unfortunately, there are no aftermarket alternatives. But, it’s not the end of the world to fabricate one. You won’t be doing it in your driveway with a hammer and a pair of pliers, but if you can get some TIG welding done, you can piece something together that works nicely. We’ve ported/enlarged the elbow, used a big twin 72mm TB, and put on a 127mm CAI (custom) on a friend’s Whipple kit, and it woke it up pretty good. Well worth the time. This kit has decent growth potential.

The as-delivered 6 rib belt system is average. It works fine at 450rwhp with a good belt tensioner. If big power is the goal, the 6 rib belt system won’t cut it. It can be upgraded to an 8 rib belt system by changing all of the pulleys (in the entire system). There are two 10 rib dedicated belt drive systems available for the Whipple, which is nice. One from Steeda and one from Whipple. We’ve played with the Steeda setup, and it’s pretty good.

The Whipple has fantastic fit and finish. It’s nearly “stock” in the sense that it looks like it was designed by Ford to be stock on the car. It’s of good quality and has no bugs in the system.

The Whipple/Ford Racing 2.3L is a great unit and should be on the short list of viable choices.

How We Rate Them/Our Picks

We put this together so you could rate them yourselves based on the facts we could gather. But, if you want to know our opinions, here they are….

We went over this a little earlier but it bears repeating. There’s no “best” blower. There’s only the best blower for your particular needs/circumstances/budget, etc. We broke this down into what blowers fit what needs best. And you’ll see that what tops the list in each category/need changes. These are the categories we used:

-Up to 450rwhp on a Stock Rotating Assembly (Motor)
-Up To 550rwhp on Pump Gas
-Up TO 650rwhp ON Pump Gas
-650-800rwhp ON e85/Race Fuel for Regular Street Driving
-650-800rwhp on e85/Race Fuel for the Dyno/Drag Strip
-Over 800rwhp on e85/Race Fuel

Up to 450rwhp on a Stock Rotating Assembly (Motor)

The stock 4.6L 3v rods and pistons can take 450rwhp before you’re in the danger zone. After 450rwhp, you run the very real risk of chucking rods out of the motor. So most people stop here. We estimate 80% so you probably fall into this category.

#1 Pick – Department Of Boost GT450 with the M122 Blower

#2 & #3 Pick (Tie) – Whipple/Ford Racing 2.3L and Roush R2300 Phase II

All the blowers but the M90 will make 450rwhp with ease, so there’s no power issue. For us it comes down to price, cooling, belt setup, packaging, and the ability to grow in the future.

The GT450 wins in almost all of the categories. It makes the same 450rwhp that all of the other kits (except the M90) but does it for far less money. It cools better than all of the others, the belt setup is good, it’s packaged very well, and down the line it will make power much easier than the other stuff available. The only real potential downside to the GT450 vs. the others is that most shops won’t want to put it on. They can’t make any money selling it, and most shops haven’t done enough of them to get it done as fast as the other kits they may specialize in. If you’re having you blower put on by a shop, the GT450 may get knocked down the list a little depending on that particular shop’s situation. If you’re doing the install yourself, it’s a non-issue.

The Whipple is a great unit. It cools OK but down the road can be modified to cool better. It’s effectively the only one that can. The belt setup is good if used with our Frankentensioner, and later down the road there are 10 rib kits available, if needed. It’s packaged very well. The Whipple can make more power in the future but it’s more difficult than the Roush and a lot more difficult than the GT450.

The Roush R2300 is also a great unit. It cools OK. Modification of the cooling is nearly impossible though. The best setup is good if used with our Frankentensioner, and, later down the road, Roush has a separate 8 rib blower drive belt system (FEAD), if needed. It’s packaged very, very well. You would think Ford made it. It’s damn near perfect. The R2300 will make more power pretty well… slightly easier than the Whipple but not nearly as easy as the GT450.

Up To 550rwhp on Pump Gas

If you “build” your motor with good rods and pistons, you can start going bonkers with boost. At 550rwhp, it still comes down to price, cooling, belt setup, packaging, and the ability to grow in the future for us. At 550rwhp, we have the same picks as the 450rwhp.

#1 Pick – Department Of Boost GT450 with the M122 Blower

#2 & #3 Pick (Tie) – Whipple/Ford Racing 2.3L and Roush R2300 Phase II

The GT450 wins in almost all of the categories. It makes the same 550rwhp as the other but does it for far less money. It cools better than all of the others, the belt setup is good, it’s packaged very well, and down the line it will make power much easier than the other stuff available. The only downside at 550rwhp with the GT450 using the M122 blower is that the M122 is getting more stretched out than the Whipple or Roush. The M122 is also a Roots Improved blower where the Whipple and Roush are Twin screw and TVS blowers, respectively. The M122 isn’t crippled at 550rwhp by any means. But it’s closer to its efficiency limit than the other two. Some inexpensive porting of the M122 does wonders though. And you could use a 2.3L TVS off of a 2013 GT500 on the GT450, which is more efficient than the Whipple and Roush. And will still come in at quite a bit less money. The only real potential downside to the GT450 vs. the others is that most shops won’t want to put it on. They can’t make any money selling it, and most shops haven’t done enough of them to get it done as fast as the other kits they may specialize in. If you’re having your blower put on by a shop, the GT450 may get knocked down the list a little depending on that particular shop’s situation. If you’re doing the install yourself, it’s a non-issue.

Nothing changes in regards to the pros and cons of the Whipple and Roush at 550rwhp.

Up TO 650rwhp ON Pump Gas

If you “build” your motor with good rods and pistons, you can start going bonkers with boost. At 650rwhp, it still comes down to price, cooling, belt setup, and packaging for us. The ability to make more power beyond this point is mostly irrelevant because very few reach this point, and most of these blowers won’t make more power anyway. At 650rwhp, we have almost the same picks as 450/550rwhp.

#1 Pick – Department Of Boost GT450 with the 2013 GT500 2.3L TVS Blower

#2 & #3 Pick (Tie) – Whipple/Ford Racing 2.3L and Roush R2300 Phase II

The GT450 with the TVS wins again in almost all of the categories. It makes the same 650rwhp as the others but does it for far less money. It cools better than all of the others; the belt setup is good as long as it’s upgraded to an 8 rib system. At this point, it’s packaged very well and down the line it will make more power if you switch over to e85. The GT500 2.3L TVS moves quite a bit more air than the Whipple and Roush. The Whipple and Roush are all done at 650rwhp…the GT500 2.3L TVS will keep going for quite a while. Depending on the combo, you can go over 700rwhp on pump gas. And it will make north of 800rwhp on e85. The only category where the GT450 loses out to the Whipple and Roush at this level is the belt system. There’s a 10 rib dedicated belt drive available for the Whipple and an 8 rib dedicated belt drive for the Roush. The only real potential downside to the GT450 vs. the others is that most shops won’t want to put it on. They can’t make any money selling it, and most shops haven’t done enough of them to get it done as fast as the other kits they may specialize in. If you’re having your blower put on by a shop, the GT450 may get knocked down the list a little depending on that particular shop’s situation. If you’re doing the install yourself, it’s a non-issue. Chances are, if you’re playing with this level of power though, you’re doing your own work.

Nothing changes in regards to the pros and cons of the Whipple and Roush at 650rwhp.

650-800rwhp ON e85/Race Fuel for Regular Street Driving

At this point, things are getting bonkers. This is well into the “very expensive” territory and only a very small percentage of cars get here despite internet “wisdom” saying otherwise. This is firmly in race car territory. Yes, you can build this sort of power to be a daily driver. But the supporting modifications to make that happen are a huge deal. The blower will be one of the smaller expenses.

The biggest hurdle with this sort of power is heat. It becomes a very big deal. E85 helps out a lot in keeping things in check though compared to regular pump gas or race gas. So, if you want to drive around on the street at these power levels, e85 really is the only way to go. And, because heat is such a huge issue, the IC design gets even more critical.

At this point, the belt system becomes a really big deal in manual transmission cars, especially cars with tall gearing (3.55s, for instance). Cars with an auto trans and short gears (4.10s, for example) are easier on the belt system. But it still has a rough life.

Most of the blowers in this guide can’t move enough air to make these sorts of numbers.

#1 Pick – Department Of Boost GT450 with the 2013’ GT500 2.3L TVS Blower

#2 Pick – Kenne Bell 2.8 or 3.2L

#3 Pick – Department Of Boost 3v R- Spec

The GT450/TVS wins out again. Up toward 800rwhp, the 2.3L blower is running out of breath, but on e85 it will get the job done. And with some porting, it will be pretty happy. The 2.8L Kenne Bell will move slightly more air than the TVS will, but it’s not a huge margin. The 3.2L Kenne Bell will move plenty of air for 800rwhp.

The GT450/TVS is going to be limited to an 8 rib conversion as are the two Kenne Bell systems. With the right tensioner and an 8 rib, you can make it work. But barely. The belt system will not be real happy. It is what it is though, there are no options to make them better.

The GT450/TVS is packaged very well and is easier to live with than the two Kenne Bell units.

The GT450/TVS really shines in its affordability. At this level, you’re not using the injectors, fuel pump solution, heat exchanger, IC water pump, and a few other small doodads that come with the Kenne Bell kits. And you pay for those. So you end up paying twice. Not only is the GT450/TVS combo less money to start with, you can spec it out however you want right from the start, so you don’t end up buying parts twice. Unless you’re working with an unlimited budget (who really is?), this is a huge deal. A couple of thousand dollars saved that you can spend somewhere else will make a huge difference.

The GT450/TVSs IC simply kicks the guts out of the two Kenne Bell blowers. There’s no other way to put it. The GT450 IC can remove 55-60% more heat than the Kenne Bell ICs. And, at this level, that counts more than ever. Just to put into perspective how much more we’re talking about, let’s look at it as HP. If you have a car that makes 400rwhp and add 55-60% you now have 630rwhp. Pretty damn significant, huh?

The only real potential downside to the GT450/TVS vs, the Kenne Bells is that most shops won’t want to put it on. They can’t make any money selling it, and most shops haven’t done enough of them to get it done as fast as the other kits they may specialize in. If you’re having your blower put on by a shop, the GT450 may get knocked down the list a little depending on that particular shop’s situation. If you’re doing the install yourself, it’s a non-issue. Chances are, if you’re playing with this level of power, you’re doing your own work though.

Where is the R-Spec in all of this you ask, and why is it in third place? The answer is price. The R-Spec is BIG BUCKS. It’s by far the best option for this segment. But you pay for it. The R-Spec has incredible cooling compared to anything else available. It can remove over 300% more heat than the two Kenne Bell kits, and that’s just the IC. It’s hard to quantify the advantages that the composite heat barrier offers because there’s nothing to compare it to. But it’s a big difference. It also has its own 10 rib dedicated blower drive, which is a massive advantage. If money were no object, it would be WAY out in first place. But, since money is a factor, it gets a third.

650-800rwhp on e85/Race Fuel for the Dyno/Drag Strip

If you’re looking for a good quarter mile time or a huge dyno number and don’t care that you’re not going to be able to make full power on the street due to high IATs, the recommendations change considerably. Cooling is not nearly the issue at the drag strip/dyno as it is in “real life.” You can also use an ice chest for the IC system for runs this short. Ice water does great things for underperforming IC systems.

The dyno is very, very easy on belt systems, so that’s not as much of a factor either. If your drag car has a manual transmission and you have short gearing, your belt system will have a tough life, but it can be made to work. Bring extra belts though. If you have an auto trans with short gearing, you can do pretty well with an 8 rib system.

#1 Pick – Kenne Bell 2.8 or 3.2L

#2 Pick –Department Of Boost GT450 with the 2013 GT500 2.3L TVS Blower

#3 Pick – Department Of Boost 3v R- Spec

In this segment, the Kenne Bell blowers do really well because their IC and belt problems are less of an issue. And they will be much happier moving 800rwhp worth of air than the 2.3L TVS. The only reason the R-Spec isn’t the winner again is money. It’s better at everything else.

Over 800rwhp on e85/Race Fuel

Things are getting so bonkers at this point that we’re not even going to break this down like the other ratings. There are only a handful of 3vs on the planet that make this sort of power anyway. In this segment, it comes down to the Kenne Bell 3.2L vs. the Department Of Boost 3v R-Spec. They’re the only blowers that will move enough air to get the job done.

If you want a quarter mile/dyno car, the Kenne Bell is a good option. Just run e85, use an ice chest, and bring extra belts.

If you want a street car/daily driver that will put down all the power all the time, the R-Spec is the way to go.

If you want to go for some seriously crazy HP numbers, the R-Spec is really the only choice. You can spec it out with up to a 4.5L Whipple blower. At the end of the day, there’s no replacement for displacement.

Wrap Up

We hope this was helpful to those of you looking to make a blower purchase for your 3v. Please don’t lose sight of the fact that there is no best blower, only the best blower for you. If you pick the right one for your needs, you’ll enjoy it immensely. If you pick the wrong one, well, you will still enjoy it, it’s a blower after all. But you could have enjoyed a different one more. Blowers are a lot of money. You don’t want to make the decision lightly and based on no facts. Gather as much information as you can.

If you haven’t done it yet, it’s now time to read our article
Boosting The 3v – Almost Everything You Need To Know

Coyote Tech

Coyote Boosting Basics - The Facts

Department Of Boost’s Commitment to Fact

The performance automotive aftermarket industry, especially the forced induction portion is littered with “fuzzy math”, half-truths and in some cases outright lies. We see it every day, all day. In some cases we think that this problem is through ignorance on the part of the industry. In others it is obviously an attempt to muddy the water or a blatant lie to drive sales. It makes us crazy. It should make you crazy too.

We commit to you to always tell you the full truth and relay the facts as we know them. Do we know everything? No, of course not. No one knows everything about an entire subject. And new theory’s and methods are continually being discovered. Additionally more and more “wives tales’ or “internet truths” are being debunked every day. But we will give you the unvarnished truth as we know it at the time. And with a healthy fear of coming off as arrogant, we know a lot.

We will always provide you with technical data to the best of our abilities. We will never give you half-truths. And we will never lie to you so we can sell more product. This is our commitment to you.

Is It Really Testing?

The first thing to get out of the way is the word “test” in the term “dyno test”. 99% of the time you’re not looking at a test, you’re looking at an advertisement. Dyno numbers are used to sell product. It’s as simple as that. Are dyno numbers worth something to you the consumer? Sure. Should they be looked at with a grain of salt? Absolutely. You’re being sold something, be aware of that.

Coyote boosting basics, the facts

Overview:
We think that the biggest misconception about forced induction (FI), specifically positive displacement and centrifugal blowers is that there is any mystery to how much power they can/will make. Here is the deal, as long as the supercharger is even close to being sized correctly (as far as we know all the Coyote superchargers are) the supercharger will not be what determines how much power the car can make (excluding full blown race builds and HP numbers up over 850). A supercharger is an air pump, that’s really it. Some superchargers are a little more efficient at “this” and others “that”. But the big picture is that 10lb of boost out of ABC blower will make the same power as 10lb of boost out of XYZ blower. So unless you are going for crazy numbers, and ready to spend crazy money to do it at the end of the day it really doesn’t matter what blower you use. Here is why…

Generally when someone asks “How much power can I safely make with a Coyote?” they are asking at what point does the motor break because of mechanical load (horsepower). Up until recently and with most motors that was the right question. For example, the first limit with the 2005-2010 Mustang GT 4.6L 3v was 450-500hp where it would break the connecting rods. The 2007-2012 GT500’s first limit was about 725hp where it would break its connecting rods. That was the engines limit without pulling it out and replacing the internals with forged components.

When the Coyote came out something interesting happened. The motor got stronger (stronger than the 3v) so it could make more power before breaking. But, the Coyote has a very high compression ratio (11:1) and a new limit cropped up. The detonation or “knock” limit. The short version is that as a motors compression ratio goes up you need more octane (better fuel) or you will get detonation and break parts. High compression ratio motors can’t take nearly the boost that low/lower compression motors do on pump fuel. Because of the Coyotes high compression ratio the safe boost limit on premium gas (93 octane) is about 10.5psi. Any more than that you are flirting with detonation and engine damage. It is not about what the motor can “make” with the coyote, it’s about what the fuel can “make”. The first limitation you run into with the Coyote is fuel, not breaking parts.

So how much power can a Coyote make safely?:
-On 93 octane and about 10.5lb of boost and spinning 7,000rpm a Coyote will make about 550hp.

“But I have seen people make 650-700hp on a stock Coyote motor on pump gas!!!” you say. And here is where the “rub” is. Where the fuzzy math comes from, and some of the lies.

Exhaust:
A Stock Coyote MOTOR can make more than 550hp on pump gas…….notice we said MOTOR, not combination. Boost is simply a representation of restriction. If you reduce the restriction you will make less boost, the same power, but less boost. So if you reduce the restriction you can spin the blower faster (which will make more power) and still keep the boost to/under 10.5psi. A very basic and widely used method of reducing the restriction is to use long tube headers, off road X/H pipe (no cats) and a high flow cat back system. Preferably something 3”. The reduction in exhaust restriction will drop the boost about 2psi. This means you can now spin the blower faster to make more power. 2psi is about 35-40hp. The exhaust is worth about 30-35hp. Now your stock Coyote MOTOR is making 615-625hp.

The “problem” with this little exhaust trick is that it introduces fuzzy math into the conversation. The blower isn’t really making more power. Well, it is, but all of the blowers are capable of upping the speed a little without running out of “breath”. What happened is someone introduced a $2000 variable (the exhaust) into the discussion but they are claiming “stock motor”. If you don’t know the exhaust is now part of the conversation you could easily make the mistake that XYZ blower makes more power than ABC blower does. But that wouldn’t be true. What made the difference was that one combo had another $2000 of exhaust into it. And that is nowhere near an apples to apples comparison. Unfortunately some supercharger manufacturers and vendors use this fuzzy math to give the impression that their product is better.

Dyno Numbers:
The exhaust trick is not the only way that fuzzy math happens. Dyno numbers are a HUGE factor when it comes to fuzzy math. Numbers from dyno to dyno are notoriously inconsistent. And that is when the dyno operators aren’t trying to tweak the results. Hot Rod Magazine did a great article on dyno’s and their results a few years ago. They took the same car (GT500) to 5 different dyno’s over the period of a couple days. Guess what happened? Lots of confusion. The car “made” between 577 and 656hp. Yeah, that’s right. A 79hp swing in results with NO changes to the car. Here is a link to the article if you want to read it (you should):

How much do you trust dyno numbers now? If you still put stock in them being some sort of “test” you’re delusional. Dyno’s were not designed to be compared to one another. Yeah, you can kinda sorta compare dyno to dyno a little. But they are not calibrated to a standard like let’s say a torque wrench. A dyno is designed to test the difference in changes when making modifications, tuning, etc on the same car at the same dyno facility. They were only ever meant to compare to themselves. For example. You take your stock Mustang to a shop. They dyno it stock. They then put a blower on it, some exhaust, etc. Then they dyno it again. The result that you get is the difference those parts, tuning, etc made on YOUR car, that DAY (or couple of days). The dyno is not magically calibrated to every other dyno on the planet so they can be compared to each other. There are dyno’s like that, but they are engine dynos (not wheels dyno’s) and mostly used by the car manufacturers because they do have a standard (consistent unit of measurement) that they need to adhere to. But having a calibrated dyno is not enough. The testing procedure also needs to be standardized and adhered too. If not, the numbers mean nothing. When you see dyno numbers for XYZ car with XYZ mod don’t forget that the tool used to measure the power (the dyno) and the procedures used to do the “test” are not standardized. If there is no standard, there is no consistency.

And that is only the tip of the iceberg when it comes to dyno’s.

Dyno numbers can be fudged. It’s very, very easy. Change a few parameters in the software and boom! More horsepower, just like magic!

The testing process can also be manipulated to show bigger gains or bigger numbers. That is child’s play. There is a massive difference between making a dyno run with the car stone cold, the hood open, huge fans blowing on it, a little more pressure in the tires, etc than driving the car in off the street, strapping it down, keeping the hood closed and running it with no cool down (you know, like every time you’re driving your car).

What you can away with on the dyno is different than what you can get away with in real life too. On the dyno everything is controlled and you have lots of sensors/data to monitor. On the street it’s far more “wild west”. You can get away with a couple more degrees of timing on the dyno. You can lean the mixture out a little more on the dyno. These are all things that will “make” more power. But you will not be driving around like that in real life. You don’t want to be that close to the edge.

Playing around with testing procedures can show 30-50hp with no problem.

Fuel:
We’ve seen one manufacturer make the statement that they test all of their stuff on 100 octane race fuel for “consistency”. Yeah, maybe they have more consistency when comparing their stuff to their other stuff. But running race fuel and a couple more degrees (or a lot of degrees) of timing doesn’t allow their numbers to be compared to everyone else’s now does it? They could be up 30-40hp.

RPM’s:
And yet another trend that we have been seeing is revving the crap out of blown Coyotes to “get” those big numbers. One very cool thing about the Coyote motor is the twin variable cam timing. In short what this does is allows the computer to adjust the cams so they can act like a “small” cam or a “big” cam when needed. Which allows them to make more power over a wider range of RPM’s. This means you can rev the crap out of it and it won’t “run out of cam” like it would if they were fixed or single variable. Rev the 3v 4.6L past about 6000rpm’s and the power just goes flat. Rev the Coyote past 6,000, 7,000 even 7,500rpm with a blower on it and it just keeps making more and more power. Pretty cool, yes. But do you want to do that? Not if you want your motor to last very long you don’t. The loads on the crankshaft, rods and pistons goes up exponentially as the RPM’s increase. In short the load difference between 6,000 and 7,000rpm is a lot more than the difference between 5,000 and 6,000rpm. And the loads get real big up past 7,000. More load means more broken parts.

A lot of manufacturers and vendors are all too happy to rev the guts out of their motors to show you those big HP numbers. If they blow the motor up they are prepared to replace it. It’s the cost of doing business. They also don’t plan on doing that over and over again for tens of thousands of miles. Are you prepared to shove a new motor in your car every time it blows up because you were revving the crap out of it? Are you prepared to reduce the life of the motor and associated components (alternators for example) to “get” those big numbers? Are you made of money? No, who really is.

We have seen manufacturers and vendors rev stock Coyote motors to 7900rpm to show you a big number. 7900rpm!!!!! Are you nuts?!?!? You better have deep pockets if you want to do that.

The Coyote will keep on making power the faster you rev it. There is a big jump in power between 7,000 and 7,900rpm’s, up to 50hp. Some manufacturers/vendors will be happy to claim those big numbers up there. But are you ready to take the same risks?

What Mods Does It Really Take To Make Those Numbers?:
Lastly, what does it really take to make those numbers? This is related to the exhaust situation. Are those numbers “real” if you have to buy more parts to get them? For example we just saw a “test” done where “they” got another 90hp out of a “stock” Coyote with a blower. The problem is that to get that extra power they had to go with bigger injectors and fuel pump booster in addition to revving the crap out off it. Oh yeah, and a “splash” of race gas. We talked about revving the crap out of it and what that entails. How about the money for those injectors and pump booster? Where does that come from? The injectors were $960 and the pump booster $260…. for a total of $1220. It’s all good if you’re willing to spend that money for the extra power. But that doesn’t make that particular blower better. It just means that the combination was pushed harder with more money and very importantly, race fuel. Suggesting that particular blower can do something the others can’t or is better based on that “test” is ridiculous.

Conclusion:
So you can make about 550hp at about 10.5psi spinning 7,000rpm with a stock Yote. If you want to make about 600hp you will be into about $2000 more in exhaust. If you want to make 700hp you will be into another $1200 in injectors/pump booster, have to run race fuel and rev the guts out of it. And that doesn’t even get near all of the other supporting mods you need to actually be able to DRIVE around with that extra power. How about a clutch? Maybe a transmission? Driveshaft? Rear suspension mods? Wheels and tires? There is a GIGANTIC difference between 550 and 700hp when it comes to the money spent. It’s not just a matter of turning the dial up all the way and letting it rip.

Take all “test” data with a grain of salt. As you saw from the examples above these “tests” can easily swing 100-150hp when you take things into account like more parts, testing procedures, dyno to dyno differences, etc.

Be careful when comparing/shopping for blowers. Unless you’re looking to spend a LOT of money and go for some stupid race car levels of power the actual blower (the compressor part of a blower kit) won’t effect how much power you can make on the Coyote much at all. What you should be looking at cooling, quality, packaging (how it fits) and don’t forget cost.

Thanks and enjoy your Coyote!!!

Questions:

We have been getting some questions about this article. Some quick and easy, others more complex. We have decided to post up the questions (and answers) that are more complex and may be helpful to other people. Here they are:

The Question:
So you are saying on 93 octane fuel, you can only make 550 hp safely on the coyote? The same limit on the outgoing 4.6? Feel free to elaborate as I’m familiar with the thermodynamic analysis of internal combustion engines, but have trouble believing this. There are just way too many people out there making much more than that on pump gas. I’m not calling you a liar; just really not understanding that low of a limit without lowering the motor’s compression. I know you know your stuff because I use to follow you religiously (you get the gist) on allfordmustangs before you even started department of boost.

Secondly, what do YOU suggest needs to be done to make 700rwhp (MAYBE like 675) with this motor and your manifold? That’s really my lower limit once I graduate this December. If I can’t make that, I’m not even going to go FI. My brother has a 500rwhp 4.6 with the on3 kit, and I’m just not satisfied with that.

Garret

The Answer:
Hey Garrett

I’ll try and break this down question by question.

Thanks
Jason

Hero Runs:
The first thing to get out of the way is that we don’t count dyno “hero runs” as real data. If it can’t be replicated on the street at full operating temp where most people are driving their cars it’s not a real HP number as far as we are concerned. When we say “it will make 550hp” we mean it will make 550hp in real life. Will our 550hp make more on a “hero run”? Absolutely. But we don’t race dyno’s and we aren’t comfortable about padding numbers for the sake of looking cool.

We believe in under-promising and over-delivering. That is not the case from what we see in most of the industry. Most of the time we see the opposite. Just yesterday I saw a post buy a guy who got a blower kit for his Coyote. He was told it would make 650 rear wheel hp. It was installed, the supplied tune was used and it made…515hp. Yeah, the dyno could have been a little soft. But that is a LONG way off 650hp. An extreme example yes, not terribly uncommon though.

You Can Make Over 550hp With A Coyote On Pump Gas:
You can make over 550hp on pump gas with a Coyote. What you can’t do (unless it is a real happy dyno and a “hero run” for the ages) is make over 550hp on a 100% stock Coyote with most out of the box blowers. This limit is an octane/boost limit. In some cases it’s also a fuel injector or pump limit depending on the kit.

Safe Limit On The 3v:
The safe limit on the stock 4.6 3v is 450hp (some have pushed it to 500, some have paid for it). That was the rods breaking though, not an octane/fuel limit. If you forge the 4.6L 3v and leave the compression ratio stock (9.8:1) you reach its octane limit at about 17-18psi and 625-650hp. That is the simple version. If you drop the compression ratio when forging the motor (most do) you can push the boost to about 20psi on 93 octane. Most people stroke them to 5.0L when they forge them too which allows for the blower to spin faster (more power) while keeping the boost at 20psi. So there is more power to be had there. We’ve run our 4.6L 3v with 9.25:1 compression ratio to 776hp on 20lb of boost with 93 octane. That is a pretty special combo though. Combo being the key word here.

“But I have Seen People Make More With Pump Gas”:
“There are just way too many people out there making much more than that on pump gas.”

But are they 100% stock with a 100% stock out of the box blower kit? Was it done on a “happy” dyno? Was the tune safe? Was it a hero run? That’s where the “fudge factor” is at. You can absolutely make more than 550hp out of a Coyote on 93 octane. It costs more money in parts for the combination though. The focus of the article was to demonstrate that a lot of the time when comparing this blower to that blower the blowers aren’t what is actually being compared. What is being compared is the additional/supporting mods that it took to make that power. And in some cases the dynos and testing procedures are being compared too.

The Limit:
As far as the “limit” goes there is a little fuzzy math there too. What is the “limit” really? Is it when parts break? Is it when you get knock (pre-ignition)? Even one “knock”?

This is how we see the limit. The limit of the boost/fuel combo is when you have knock showing up in the logs (computer data). Even just a little. We don’t like knock. Knock is bad. There is another “rub” here too.

The ECU (computer) in the Coyote is really, really smart. Crazy smart actually. It’s amazing what is coming from the OEM’s stock and how much processing power they have. There is no way the stupid power numbers you see nowadays could be made without that sort of processing power. With some of that “smartness” comes the ability to find wiggle room when it comes to claimed power numbers though. Unlike in the old days when the motor knocks (to a point of course) it won’t immediately start damaging stuff. The ECU will detect that knock and pull back the ignition timing, richen up the fuel mixture or even close the throttle blades. Or a combination of all those. It all depends on what the computer sees for data. The ECU will “save” the motor from itself. This is obviously a good thing.

Here is where things get complicated and where you can see where a hero run can be worth so much power on the dyno.

The ECU also monitors things like cylinder heat temp (CHT) and intake air temp post intercooler (IAT2). This data will be combined with things like knock data and depending on the big picture it draws for the ECU it will pull no, a little or lots of ignition timing. Add fuel. Or just shut the party down by closing the throttle blades. When you’re on the dyno making a run with a 160deg CHT, a 75deg IAT2 and you get a bit of knock it may not pull timing, richen things, up, etc. But it probably won’t knock at all with temps that low anyway. It will NOT run at those temps on the street in real life though. The CHT’s will be more like 195-210deg and with most blower kits (not ours, ours are lower) you will see IAT2’s at 120-130deg. Real life is a lot different than on the dyno.

So what is the “limit”? The computer will obviously save the motor from itself, to a point. You could be driving around on the street down on power all the time from what it made on the dyno and it’s still “safe”. But is that really what you want to be doing? Leaning on the safeguards? Or do you want to set it up on the dyno, at street temperatures, and not lean on the safeguards? The former will show more power on the dyno. But it won’t make more power in the real world.

We feel that “the limit” is to be tested under real world conditions. Not fantasyland. The funny thing is that if you take a fantasyland/ hero run/ dyno queen that makes 600hp out on the street it will probably be SLOWER than the 550hp car that was set up for real world conditions on the dyno. When those safeguards kick in on the fantasyland setup they shut the fun down hard. The ECU is not correcting to “maximum safe street power at full temperature”, it’s correcting to SAFE.

We recently saw one of the manufacturers say (I can’t believe they said this in public) that their 650ish hp tune (I can’t remember the number exactly) was safe at 12.5psi because if it saw knock, high IAT2’s, high temps, etc it would simply shut the throttle a little bit. What I saw reading between the lines is “When conditions are perfectly favorable it will make 650hp at 12.5psi”. The problem is that unless it’s on the dyno or stone cold at the drag strip the conditions won’t be perfectly favorable and it runs around with the throttles closed a bit all of the time……making less power. So does it really make 650hp? I say no.

The Horsepower Thing:
This entire horsepower thing has gotten way out of hand over the past 15-20yrs. One ingredient is that there are a lot more dynos out there now. Another is the internet. And lastly it being leveraged as a sales tool. “Back in the day” we didn’t know how much power our cars made. We knew what we could beat in a race and maybe what it ran at the drag strip. There was no “dyno racing”.

We’re not huge fans of using 1/4mi times to measure a street cars performance (working on an article about this now). A good street car is not a good drag car. There are no two ways about it. And there are a ton of variables in a1/4mi elapsed time (ET) other than horsepower. Traction, gearing, suspension setup, etc. So ET is not a good measure of the cars performance. But MPH is. For the most part XXXhp will make XXXmph at the drag strip (in the same kind of car) regardless of traction, etc. Yes it will vary some, but not nearly as much as ET. If someone really wanted to know what sort of power they are making they can go to the dragstrip, run the car at full operating temp and see what they get for a MPH. I can’t tell you how many “600hp” cars I have seen run at the strip and only trap at 122-123mph. Guess what? That’s not a 600hp car, that’s a 500hp car. I don’t care what the dyno graph says.

What Would I Do To Make 700hp On 93 With A Coyote?:
The big variable in this answer is do you want to do this on a stock motor? The answer gets two completely different suggestions.

Stock Longblock Combo
Well, this will be on the edge. No two ways about it. You can push all of the factors in your favor and you will still be hard pressed to get a real deal 700hp out of a stock long block on pump. And then comes the question of how long will it stay together. It will be on the fuel and mechanical limit. This is the combo I would run.

-GT550-S197 Stage I
-2013 GT500 2.3L TVS blower (or 2.9L Whipple)
-A BIG TB. Something like the FPRR Cobra Jet
-A BIG CAI. Something like the 127mm JLT, if not bigger
-The biggest nastiest long tube headers I could find
-A full 3” off road exhaust with some sort of “straight through” mufflers
-Whatever it took for fuel system/pumps. I’m not real up on what will do exactly what and their limits. I would not rely and just a pump booster though personally. Some sort of big pump/pumps would make me feel better.
-ID1000 injectors
-The biggest nastiest heat exchanger I could get my hands on
-The biggest nastiest intercooler water pump I could get my hands on
-A quality harmonic balancer
-Billet oil pump gears
-170deg thermostat
-Urethane motor mounts

This will probably make a real 700hp. You will be spinning its guts out though. Probably past 7500rpm. And this combo will let go some day. It’s not bulletproof. It’s on the edge.

Forged Motor Combo:
This one is easier to hit 700hp with because of compression ratio and volumetric efficiency (which I’m not getting into here). It’s also not as scary because the chances of parts flying out of it are a lot lower!

-Forged bottom end with 9.0-9.25:1 pistons
-GT550-S197 Stage I
-2013 GT500 2.3L TVS blower (or 2.9L Whipple)
-A BIG TB. Something like the FPRR Cobra Jet
-A BIG CAI. Something like the 127mm JLT, if not bigger
-The biggest nastiest long tube headers I could find
-A full 3” off road exhaust with some sort of “straight through” mufflers
-Whatever it took for fuel system/pumps. I’m not real up on what will do exactly what and their limits. I would not rely and just a pump booster though personally. Some sort of big pump/pumps.
-ID1000 injectors
-The biggest nastiest heat exchanger I could get my hands on
-The biggest nastiest intercooler water pump I could get my hands on
-A quality harmonic balancer
-Billet oil pump gears
-170deg thermostat
-Urethane motor mounts

This will make 700hp on pump pretty easy. Even easier with the 2.9L Whipple. You won’t have to spin the motor as fast, but you can if you want. The forged bottom ends are a lot more tolerant of RPM.

Summary:
A stock Coyote makes about 365-370hp. Your standard blower kit will get you 550hp for $6500ish and $4700ish for our kit (less during the group buy, even less if you do a Stage I and build it up yourself). That is 185hp for $6500 with other kits for a $$$/hp ratio of $35/hp. Our kit is $25/hp.

Going from 550hp to 700hp is ANOTHER 150hp. Almost the same jump that the blower itself made. That’s a BIG jump. The stock longblock combo will cost about another $5900 for 150hp for a $$/hp ratio of $39/hp. So it’s not at the point of diminishing returns, but it’s getting there. The forged combo is about $10,000 for a $$/hp ratio of $66/hp. That is well into the point of diminishing returns. And remember, this doesn’t include any labor.

IMO going from 550-650hp makes sense. It can be done at a fairly safe level on a stock shortblock and doesn’t cost any more than the original blower kit. Going from 650-700 is where the big bucks come out if you want to do it “safely”. That last 50hp, which will just be extra tire smoke 99% of the time, is just not worth all the time and effort.

I hope this answers all of you questions

General Tech

Belt Tensioner Tech

Belt tensioners are very misunderstood or maybe a better word, if it’s a word is under-understood. A belt tensioner has a lot of jobs. And when you add a supercharger to the mix more yet.

Let’s start off by making it clear that the stock/OEM serpentine belt system was not designed to run a supercharger in any way shape or form. So right from the start we have that going against us. Don’t lose sight of the fact that the supercharger is not supposed to be there. If you look at most OEM supercharged cars they have a separate belt to run the supercharger with a wider belt and a beefy tensioner.

The Tensioners Job

The belt tensioner has a lot of jobs. The main and simplest one is to provide enough pressure to keep the belt tight so it doesn’t slip. It is also responsible for taking up the slack in the belt as it stretches under load. Lastly the tensioner is supposed to not allow the belt to go “solid” or tight (more on this below). That is a lot of jobs for something that is so simple, and it gets a whole lot more complicated when a supercharger is added to the mix.

Spring pressure

The tensioner has a spring in it, that is what provides the tension/pressure on the belt. The spring is a “progressive” rate spring. I could spend pages outlining the difference between progressive and liner rate springs, but I won’t. If you want to understand the difference in detail a quick search will get you all sorts of information. The short version is that with a progressive rate spring the further the spring is compressed the more the rate (stiffness) goes up. For a tensioner this is good, for something like a valve spring, not good. The OEM tensioner was designed to cope with the stock accessories, not a supercharger and the stock accessories. In simple terms think of the accessories and supercharger as “weight”. The more “weight” you have the stiffer the spring needs to be. Clearly when adding a supercharger you need a stiffer spring. But why?

There are two reasons why you need more spring pressure. The first one is simple. Because you are adding a supercharger, which “weighs” a lot more than the accessories the belt needs more traction/pressure or it will slip on the supercharger pulley. The second reason is more complex.

When the motor and supercharger change speeds dramatically in relation to each other, like during a gear change, hitting the rev limiter or spin/hooking the tires the belt wants to go “tight”. The rotors in the supercharger represent quite a bit of weight (much more than the spinning parts in the accessories) and a lot of kinetic energy. When you make let’s say a gear change from 2nd to 3rd at redline the engine drops about 2,000rpm. The motor is directly hooked to the transmission, rear end and ultimately tires which means that the RPM’s drop instantly. The tires contact with the road works like a brake for the motor. The supercharger on the other hand is spinning at 13,100-18,000 rpm and is being slowed down to 8,700-13,600rpm during that gear change. The “problem” is that the only thing slowing the blower down is the motor, which it is connected to it by the belt. Well, that belt isn’t terribly happy about slowing the blower down and what happens is that the belt goes tight, real tight, and tries to slam the tensioner off of its maximum travel stop. This is a problem, a couple of big problems.

The belt can/will slam the tensioner off of its maximum travel stop so hard that it will bend the tensioner arm. Take a look at your tensioner………how hard would you have to hit that arm with a hammer to bend it? Pretty hard huh? I have even seen tensioners ripped off the front engine cover! That’s hard! The first and most dramatic problem with the tensioner bending is that the pulley is now at an angle and the belt comes off. You can put it right back on. But it will come right back off again as soon as you start the car. You’re stranded. I’ve also heard of belts breaking but I have never seen it. Most people at this point put a tensioner with a stronger arm on, it doesn’t bend anymore and all is good, or is it? The answer is no, it is not “all good”, far from it. The only thing a stronger tensioner arm does is make it so you aren’t stranded on the side of the road from bending, which is a good start. But it doesn’t solve the problem. What is the problem?

The problem is that when you change over to a tensioner with a stronger arm and don’t increase the spring pressure or travel (more on this later) you have only put a band aid on things. You still have a big problem and that is the tensioner slamming into its maximum travel stop. All of the force that it took to bend that tensioner arm is still there, the arm is just strong enough not to bend. Now all of that force is transferred to the pulleys and crankshaft snout. Would you hit the end of your crankshaft with a hammer hard enough to bend a tensioner? Nope, that would be crazy. But that is exactly what happens when you bottom a tensioner. And it gets worse. The snout of the crank goes through the oil pump (it drives the oil pump). Whack the crankshaft hard enough and the oil pump gears shatter……and you just bought a motor. This is not uncommon, there are a lot of smoked motors out there because of shattered oil pump gears. So many that there are super high dollar aftermarket billet steel oil pump gears available.

No one knows for absolute 100% certainty what causes oil pump gears to shatter. Like most things mechanical there could be multiple causes. But, a large portion of motors with shattered oil pump gears have a supercharger and a tensioner that will bottom. We have never heard of shattered oil pump gears on a blown car running a tensioner that can’t bottom. It’s probably happened, but it’s rare.

So how is this solved? Partially it is solved with more spring pressure. A LOT more spring pressure. It took us getting a Gates belt tension gauge and doing a lot of checking before we got an idea how much spring pressure was really needed. When we built the first Frankentensioner we thought that we probably had too much spring pressure and would wear the pulley bearings out faster. But we didn’t care, worn out pulley bearings were much more preferable to bent tensioners and shattered oil pumps. Ends up that having double the spring tension (two tensioners) was just right according to the Gates and Dayco belt engineers. Yes, the tension is right at the top of the range, but just fine. We found every OEM and aftermarket tensioner that we tested (we did a lot of testing) didn’t have enough belt tension. About half of the aftermarket tensioners had more tension that stock, but still not nearly as much as you would want.

What is the problem?

The problem is that when you change over to a tensioner with a stronger arm and don’t increase the spring pressure or travel (more on this later) you have only put a band aid on things. You still have a big problem and that is the tensioner slamming into its maximum travel stop. All of the force that it took to bend that tensioner arm is still there, the arm is just strong enough not to bend. Now all of that force is transferred to the pulleys and crankshaft snout. Would you hit the end of your crankshaft with a hammer hard enough to bend a tensioner? Nope, that would be crazy. But that is exactly what happens when you bottom a tensioner. And it gets worse. The snout of the crank goes through the oil pump (it drives the oil pump). Whack the crankshaft hard enough and the oil pump gears shatter……and you just bought a motor. This is not uncommon, there are a lot of smoked motors out there because of shattered oil pump gears. So many that there are super high dollar aftermarket billet steel oil pump gears available.

No one knows for absolute 100% certainty what causes oil pump gears to shatter. Like most things mechanical there could be multiple causes. But, a large portion of motors with shattered oil pump gears have a supercharger and a tensioner that will bottom. We have never heard of shattered oil pump gears on a blown car running a tensioner that can’t bottom. It’s probably happened, but it’s rare.

So how is this solved? Partially it is solved with more spring pressure. A LOT more spring pressure. It took us getting a Gates belt tension gauge and doing a lot of checking before we got an idea how much spring pressure was really needed. When we built the first Frankentensioner we thought that we probably had too much spring pressure and would wear the pulley bearings out faster. But we didn’t care, worn out pulley bearings were much more preferable to bent tensioners and shattered oil pumps. Ends up that having double the spring tension (two tensioners) was just right according to the Gates and Dayco belt engineers. Yes, the tension is right at the top of the range, but just fine. We found every OEM and aftermarket tensioner that we tested (we did a lot of testing) didn’t have enough belt tension. About half of the aftermarket tensioners had more tension that stock, but still not nearly as much as you would want.

Tensioner travel

The most overlooked thing about belt tensioners is the travel. Travel is how far the tensioner arm will swing between zero tension (no belt on it) to bottomed out. The travel is critical to a correctly running belt system. The stock travel was never meant to cope with the much higher loads a supercharger puts on the belt.

Belts stretch a lot more than you would imagine. And the longer the belt, the more it will stretch. A 100” belt will stretch twice as much as a 50” belt. A stock belt is about 100” long. A supercharger belt is about 130” long. That’s 30% longer. Rough math says that right off the bat you need 30% more travel to deal with the extra belt stretch.

So how is travel connected to belt stretch?

Before you put a belt on your car the tensioner is sitting on its minimum travel stop (MTS). You put a pry bar/cheater bar on the tensioner, swing it down some and put your belt on. Note how the tensioner with the belt on is no longer on its MTS. It is somewhere in between the MTS and maximum travel stop. The reason you can’t have it on the MTS is twofold. Firstly because of the springs progressive nature there is very little pressure on the belt so it will slip. You need to have some preload (get into the spring more) for there to be enough pressure to keep the belt tight. The second reason is when the belt is loaded by the supercharger it stretches the belt and the belt gets loose. You need the tensioner to be far enough into its travel that when the belt stretches it doesn’t put the tensioner so close to the MTS that it loosens up and slips. Just set things up so the tensioner is further into the travel then, it will solve the problem. Right? Wrong. You also need to have enough travel in the other direction to deal with gear changes, etc that want to slam the tensioner off of its maximum travel stop. This is where travel becomes very important.

You need enough travel so that the belt won’t go loose under acceleration and enough travel where it won’t go tight (hit the maximum travel stop) during gear changes, banging the rev limiter and spin/hooking the tires. Tensioners with stock travel do not have enough to do both. You either get a tensioner that hits the maximum travel stop, loosens up under acceleration, or both. There is no way to cheat not having enough travel.

Conclusion

Just because you’re not chucking belts or bending tensioners doesn’t mean your tensioner is working correctly. You could still be slamming into the maximum travel stop (you probably are), experiencing a little belt slip during WOT/high RPM’s, or both.

We have never ever seen a tensioner that is strong enough, has enough spring pressure and enough travel aside from ours. Never.

Would we like to offer a big beefy awesome looking tensioner with enough spring pressure and travel? We sure would. Are we capable of designing and producing a tensioner like that? Absolutely. Is the market big enough for two super high dollar billet tensioners (there is already a high $$ billet tensioner out there)? Probably not. How many people can really afford to plop down $400 or so on a tensioner? Not as many as can’t. So we offer a solution that solves all of the problems other tensioners don’t, and for very little money. Yeah. It’s not pretty. But at the end of the day what do you want, a pretty tensioner? Or one that works? What is more important, how a tensioner that you can hardly see looks? Or having maximum boost and not beating up your crankshaft/oil pump gears?

Why You Want To Run Drop/Urethane Engine Mounts On Your S197

Here is what they will do for you:

Better Shifting

The stock mounts are liquid filled rubber jobbies that move all over the place. They were not meant for 400+ft lb of torque. If you look at one of these cars on a dyno you can see the motor twisting like mad. Because the shifter is mounted to the body and the transmission at the same time you get bind in the shifter when under power. The more power the more twist. The more twist the worse the shifting gets. Fix the twisting and you fix a lot of the shifting problem. I would say 50%. It won't turn the shifter into T56 Magnum which has no external shift linkage attached to the body, but it makes it a whole lot better. Coupled with a good shifter it's pretty damn good.

Driveline angle

The S197 has horrific driveline angles. This is one reason it has a 2pc driveshaft stock. And they get worse when the car is lowered.  A 1pc driveshaft will usually create vibration and/or harmonics issues. I stress usually, not always. It's a tricky business. Anyway, dropping the motor 1/2"-3/4" improves driveline angle considerably. These mounts allow you to do that. If you also shim the transmission mount up you can get the driveline angle almost perfect. 200mph rated!

Hood clearance

With a blower hood clearance is paramount. If your stock engine mounts are blown out the motor will move enough to contact the hood. Not ideal obviously. When you drop the motor, you open that clearance way up. And of course, it won't twist anymore so it can't get into the hood.

If you want to fit a strut tower brace between the blower and the hood 3/4" is about a mile. It's the difference between fitting and not fitting.

Broken engine mounts

The stock liquid filled mounts have and will break. Especially as these cars are getting older.

Easy to Install

I install these from the top. That's right, I don't even jack the car up. Just loosen up the stock mounts, put a jack under the motor, jack the motor up, and swap the mounts out. A few have given me a little trouble because for some reason the stud on the stock mounts is longer on some years. If you have the long stud, they won't pop right out. You either whack the stud in half (what I do). Or you loosen up the engine mounts/ears (the aluminum "mounts" on the block) until the rubber mounts will come out. You do have to get on your back for that. Still easy though. I can do a set of these in a half an hour to forty-five minutes. And I'm not fast at anything when it comes to wrenching.

Other notes:

Will I Be Able To Feel The Vibration?

If you go way out of your way you will be able to detect more vibration. But this is just me being 100% straight forward. If it's a problem for you.............................sell your Mustang, and get a minivan.

Will I have Header Clearance Problems?

This depends on what headers you have and how far of a drop you're going for. They clear the stock manifolds by a mile. I've dropped the motors 3/4" with the Kooks 1 5/8" headers (same as the Pypes). I don't know about the Kooks 1 3/4" units. You can go at least 1/2", maybe the full 3/4". If you want the whole 3/4" with the big Kooks a little grinding on the K member will clear them. They won't clear the 1 7/8" ARH loooooonnngggg tubes at a 3/4" drop. It looks like they will clear at 1/2". And if they don't, a little grinding on the K member will clear them. I've never tried the MAC, JLT's, etc. But it's a pretty safe bet that they will clear at 1/2".

So there you go. That is why you want a set of drop/urethane engine mounts.

SAVE FOR LATER
TECH