Boosting the 3v with Positive Displacement Superchargers

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Almost Everything You Need to Know

Updated 1/31/23

Be Sure To Check Out The Sister Article To this One

3v Positive Displacement Supercharger Buyers Guide

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 for 17 years 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. And that experience/data is vast. At this point we pretty much own the 3v PD blower market and a majority of the nasty nasty 3v builds out there are running our stuff.

-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 675rwhp. 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 efficiency. 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).

 GPM – Gallon per minute. This is the measurement used for how fast the water moves through the intercooler system.

 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

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/work. 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/450rwtq 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. Actually, we’ve never seen the stock crank break. 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. It’s not out of the realm of possibility that the block can handle 2000rwhp. 4.6L Cobra blocks have handled a lot more and they’re not that much different.

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. Sorta. You will wear stuff out faster. And if you smack the rev limiter (never a great idea) you may spit rocker arms out. 7,800rpm 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. Most “big build” 3v’s spin to 7,250-7,500rpm.

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 have seen no evidence that ported heads will net you one single horsepower until you’re making 750rwhp+. And even then, the data is pretty thin. Almost all 3v build will not need ported heads. Save your money for something you do need.

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 600-650rwhp. 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 (because 18psi will blow stock rods/pistons right out of the motor). 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 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 “22psi worth of power”. Those engine mods you did didn’t “make” more power. They allowed you to run the blower at a “22psi blower speed” and stay under the octane limit. You may pick up a few HP because you’re decreasing how hard the blower has 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. These numbers represent how much air that particular blower can pump into the motor. 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 - 400-420rwhp.

 -Magnuson Magnacharger 1.9L - 570-580rwhp.

 -Department Of Boost GT450 w/ a M122 Supercharger 575-585rwhp

 -Edlebrock EForce 2.3L TVS - 580-590rwhp.

 -Kenne Bell 2.6L Stage I - 585-595rwhp.

 -Kenne Bell 2.6L Stage II -  590-600rwhp.

 -Department Of Boost GT450 w/ a M122 Supercharger 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

 -Department Of Boost GT450 w/ a 2.3L Roush/VMP Gen1 - 625-645rwhp

 -Department Of Boost GT450 w/ 2.3L 13’ GT500 “Trinity”- 625-645rwhp

 -Department Of Boost GT450 w/ a 2.3L VMP Gen2 – 650-675rwhp

 -Department Of Boost GT450 w/ a 2.3L VMP Gen2R – 660-685rwhp

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

 -Department Of Boost GT450 w/ a 2.65L VMP Gen3/3R – 710-725rwhp

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

 -Department Of Boost GT450 w/ a Whipple Gen5 3.0L – 715-735rwhp

 -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:

 -Department Of Boost GT450 w/ 2.3L 13’ GT500 “Trinity”- 775rwhp

 -Department Of Boost GT450 w/ a 2.3L VMP Gen2 – 810rwhp

 -Department Of Boost GT450 w/ a 2.3L VMP Gen2R – 835rwhp

 -Kenne Bell 2.8L and 2.8LC - 850rwhp

 -Kenne Bell 3.2LC - 1100rwhp

 -Department Of Boost GT450 w/ a 2.65L VMP Gen3/3R – 1150rwhp

 -Department Of Boost GT450 w/ a Whipple Gen5 3.0L – 1200rwhp

 -Department Of Boost Gen4 3.4L 3v R-Spec – 1200rwhp

 -Department Of Boost Gen4 4.0L 3v R-Spec – 1300rwhp

 -Department Of Boost Gen4 4.5L 3v R-Spec – 1400rwhp

 -Department Of Boost Gen5 3.8L 3v R-Spec – 1500rwhp

 

 “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. If you think XYZ blower from the list above makes 50rwhp more, cool, it does. Just take the rest of the numbers for the rest of the blowers and increase them the same percentage. It’s all relative.

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:

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 Wiring 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

Subtract 25% from the horsepower number if you want to know what power these support on e85

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

-255lph pump. 450-475rwhp capable.

-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.

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

-570lph pump 700rwhp capable. Wire upgrade required at this point.

 

Fuel Pump Combinations Using the GT500 Dual Fuel Pump System

-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 below.

-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 255lph 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.

 

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

 

Subtract 25% from the horsepower number if you want to know what power these support on e85

 

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. These can’t be used on boosted motors.

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. $$$$$$$$

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

Cams

The first thing to get out of the way is that we’re not big fans of running aftermarket cams with PD blowers until you’re playing with about 750rwhp. It’s not because we don’t like cams, we love them. Who doesn’t like the rumpidy, rump, rump of cams? It’s just that non stock cams on PD blown 3v’s don’t seem to do anything for you aside from moving the power band around until you’re making big power. This means that you’re spending money/time on something that doesn’t show up in actual performance. And in a lot of cases they will hurt performance. We’re fans of HP/$$$, and cams are a pretty bad value for most 3v PD combinations. Don’t get us wrong or misunderstand. Cams will “make” a little power up top on the rev range (assuming you have a built bottom end that can rev that high). But it comes at the cost of power down low and through the midrange. “Gaining” 20hp up top is not a gain if you lost 40ft lb through the midrange. The only time that makes sense is for a drag car with really short gearing (because it will never be in the mid range).

 Every cam for the 3v will cause you to lose torque. We’ve had a car lose 40ft/lb at under 4,500rpm on a 550rwhp combo with fairly mild cams (Comp 127350’s). And this was with the VVT still functional. It gets worse when the cams are locked. 40ft/lb is absolutely something. You will absolutely feel the difference. And we got no more HP higher in the rev range to make up for it.

 “When is it time to go with cams, why and which ones?”

 As discussed above it’s time to go with cams at about 750rwhp. But it’s probably not for the reasons you think.

 First and foremost, we feel the biggest reason to go with cams is to kill some of the low end torque. “Wait a minute! You said that was bad!”. There is a big difference in torque between a 450rwhp, 600rwhp and 750rwhp car. At 750rwhp that torque starts to be come a liability. You can only generate so much traction. And if you do have a lot of traction that much torque starts to “twist” the chassis/suspension in knots and make the car harder to drive. So, you either get more tire smoke (sometimes fun!) and a car that is getting to be a handful to drive. We like knocking a little torque out at this point. Don’t worry, you will still have a ton of it.

 Second, the cams will also push the power up further in the rev range which extends your “power window”. This makes gearing less critical. It also allows you more time to get a shift in. When you’re playing with 750rwhp stuff starts to happen fast. Another second to get a shift in doesn’t seem like much, but it’s an eternity when things start to go pear shaped. Which at 750rwhp they sometimes do.

 And third. You guessed it. You will make more top end HP at this point. Not as much as you would think though. If you have a BIG blower (2.65L+) you may see 50rwhp after 6500rpm with a combo making 650+rwhp, which is nothing to sneeze at. But it’s not earth shattering. If you have a REALLY BIG blower (3.0L+) you will see a bigger gain. Maybe 75-85rwhp. You’re playing with an incredibly expensive combo that runs on e85 at this point though. The cost of cams is a drop in the bucket.

 What cams should you go with? Well, there are a lot of cams out there and this could get deep in the weeds so we’ll keep it simple. For a real street car that acts like a street car that you want to drive, put gas in it, change the oil and wash it, we like the Comp 127450’s. If you want a “race car” we like the Comp 127550’s. We don’t feel that the Comp 127350’s are worth the time, effort and money. And the Comp 127650’s are a fantastic way to beat your valvetrain to death.

 “But what about “Rumpidy Rump” cams for the sound?!?!?!”

 Yep, we get it. Who doesn’t want to hear a lumpy idle? They’re awesome. And there are a few companies that make “rumpity rump” cams that don’t require valve springs or any changes to the VVT. Ford Racing Hot Rod cams, Comp Thumper cams and Todd Warren also has a set. They just drop in and make cool noises. They’re very popular. If you want to spend the $900+ for “rumpity rump” cams because you like the noise that much, go for it. We understand. We like them too. Just be aware they you will lose torque and they will not make much power at all. You’re buying them because you like the sound.

Variable Valve Timing – Lockouts- Limiters

We see a lot of discussion/questions pertaining 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:

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, some don’t. The VVT works great, and it really improves low and midrange torque. And if you have a street car, 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 on a 450rwhp-550rwhp car. 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 may want to go with lockouts. Most of the cams for this sort of combination will require locking them out anyway.

Displacement

The 4.6L 3v is you guessed it, 4.6L in displacement. When it’s time to rebuild the motor or put a forged rotating assembly you have displacement options by way of a longer stroke or a bigger bore. In most cases it’s going to be because of more stroke. The three most common choices are 4.75L, 5.0L and 5.3L.

 What does more displacement get you?

 Well, more displacement gets you more power…….sorta. The best way to think about it is that it allows you to make more power. PD blowers are the “gatekeeper” of airflow into the motor. If the motor is 2.5L or 7.5L the amount of air going through the motor will be the same (as determined by how much air the blower pumps). Airflow (or air volume) plus fuel and spark equals horsepower. You need more air to make more power (and the appropriate amount of fuel of course). If you increase your displacement your boost will drop. Your power won’t drop, the boost will. Boost is just a measure of restriction. If you put the same amount of air through a bigger motor it is restricted less. Hence the boost drop. So, what does this boost drop do for you?

 Boost drop does a couple of things

 If you are limited to running 91 or 93 octane boost drop can do quite a bit for you. At a certain point you will have more boost than the fuel can handle without detonating (detonation is VERY BAD). Let’s just play with some round numbers. You have a 4.6L 3v at the stock 9.8:1 compression ratio with a VMP Gen3R blower on top and you’re making 700rwhp on 93 octane. You’re at the limit of the fuel. The blower will make a lot more power. But that means that it will make more boost. And your fuel can’t handle that boost. So, what do you do? One option is a more octane resistant fuel like e85 or race gas. These are not practical options for a lot of people though. So, what else can you do? You guessed it, increase the displacement, which will drop the boost. That boost drop will allow you to spin the blower faster (more air) and get that boost level back up to where it was before. Now you’re putting more air through the motor and can still run 93 octane. Check these numbers out (these are all assuming the blower is big enough to take advantage of the boost drop):

 -Going from 4.6L to 4.75L will drop the boost about 1psi.

 -Going from 4.6L to 5.0L will drop the boost about 2.25psi.

 -Going from 4.6L to 5.3L will drop the boost about 4psi.

 -Going from 4.6L to 5.4L will drop the boost about 5psi.

 -Going from 4.6L to 5.8L will drop the boost about 7psi.

 -You get about 25rwhp per pound of boost.

 -If you go 4.75L you will be able to make about 25rwhp more

 -If you go 5.0L you will be able to make about 55rwhp more

 -If you go 5.3L you will be able to make about 100rwhp more

 -If you go 5.4L you will be able to make about 112rwhp more

 -If you go 5.8L you will be able to make about 165rwhp more

 How do you get more displacement?

 There are “stroker” kits that will get you 4.75L or 5.0L. These can be put in a stock block and run as is. Easy peasy.

 If you want to go 5.3L you have to get a hold of a Ford Racing BOSS block. It is a completely different design than the stock 4.6L block that allows you to run a bigger bore as well as a longer stroke all while maintaining the stock deck height (the motor doesn’t get taller). These blocks do have their drawbacks though. They’re hard to get now, they’re expensive, and they only come in iron (the 4.6L block is aluminum). The iron block weighs about 90lb more than the stock aluminum one. They also ironically aren’t as strong as the stock block and you can’t make huge power with them.

 If you want to go 5.4L you only have one choice of blower kit. Well, technically you have two, but one of them is completely unsuited for this sort of application and would be a massive mistake (the EForce). We make a intake manifold/intercooler specifically for the 5.4L 3v combo. It also happens to be the best performing highest technology intake/intercooler in the business. It’s perfectly suited to a build of this magnitude. Now that the blower bit is out of the way, how do you go 5.4L? Well, it’s easy and hard-ish. The easy part is you can use any of the 5.4L Modular blocks (F-150, GT500, etc). The F-150 block you can of course get for not much money at all. They only come in iron as far as we know though. Aluminum GT500 blocks on the other hand are not inexpensive. But they’re a lot lighter. The motor gains about 20mm in height so that has to be accounted for. This is not a “direct swap”.

 If you want to go 5.8L you have the same blower choice as the 5.4L (no choice at all really). In this case you would use a aluminum 13-14’ GT500 5.8L block. They are of course not cheap (as of this writing they’re $3500). You can also sleeve a aluminum 5.4L GT500 block to 5.8L. But sleeves cost about $2000 that would have to be added to the cost of the 5.4L block. Obviously, we’re in max effort rareafied territory here.

 What are the downsides to more stroke?

 There are a lot of little ones that we could get really in the weeds about, but in practice there really aren’t any. Yeah, sure. If you were doing some sort of zillion RPM race motor making stoooopid power you may want to not stroke the motor. But we’ve literally never seen this situation arise. Not once.

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 popular to build high compression motors. We see this happening for three reasons.

 -It’s “fashionable” to run higher and higher compression ratios on boosted motors. We think its more trend than substance….to a point.

 -e85 is available. Which you will absolutely need for as high compression boosted motor. You 93 octane pump gas days will be behind you.

 -If your supercharger doesn’t move enough air (it’s not big enough) to reach your power goals another way of getting there is with more compression ratio. A lot of people feel “locked in” to the blower they have and don’t consider that it may be easier to reach their goals starting over with a different (bigger) blower.

 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 position 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 cars combo could result in wildly different results than another. We can’t imagine the IAT reduction is very much though.

 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 11.5:1+.

 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 9.25-9.8:1.

 Blower Is Huge and I Can Only Run 93 Octane – In this case, we’d run the compression ratio at 8.0-8.5:1. This will allow you to run quite a bit more boost (more air) and still remain on 93 octane.

 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.

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 and the ARS Race tensioner that works correctly. End of story. Nothing else 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).

 

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 about 700rwhp. 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 about 700rwhp. 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 about the same power.

Combinations

The Entry Level 450rwhp Combo

-Cost from stock to 450rwhp – $4,500-7,500

-Cost per horsepower from stock to 450rwhp – $25-43 per HP

The low-end cost above represents what it costs for the absolute bare minimum, which will only make 450rwhp on the dyno. In the real world it will have IAT issues and be down quite a bit of power. At the high end you get a fully sorted combination that will give you no trouble and make full power all of the time.

 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 measurable 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 measurable 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.

What Is Our Suggested 450rwhp Combo?

This is what we would do for a 450rwhp combo (absolute bare minimum).

 Department Of Boost GT450-450HP

 -Department Of Boost GT450 GenII

-Manifold composite heat barrier option

-Frankentensioner Belt tensioner

-Urethane engine mounts

-Department Of Boost Super Single 14gpm Intercooler System Option

 This will get you a system that will make 450rwhp all of the time and be stone reliable. We have lots and lots of customers who daily drive this combination as if the car came from Ford that way. This system can grow all the way up to 1000+rwhp.

 Why we chose this combo (no really, it’s not because it’s ours!)

 We chose this combo because to attain the same level of performance out of the other options it will cost you more money. And with a majority of those other options you can’t achieve the same level of performance no matter how much more money you throw at them. At the end of the day it comes down to performance/ dollar and if you put pen to paper our stuff unquestionably comes out on top.

 What are your other options?

 There are only two systems other than the Department Of Boost stuff still available for the 3v new. There are of course used systems, but that can be a can of worms. What is available and what do you get? For a very detailed description check out the sister article to this one 3v Positive Displacement Supercharger Buyers Guide. It has all of the facts, figures, etc of every 3v PD blower out there. After you read through the article you will come to the same conclusion we did. Our GT450 kit is the best option. It costs less and it has much better performance. In most cases the other options can’t match the GT450’s performance no mater how much money you throw at them.

Summary: 450rwhp

 The low end of the cost estimate ($4500) involves you starting with our intake manifold/intercooler and collecting the rest of the parts to complete the kit yourself. And you were really good at shopping for good deals. The high end of the estimate ($7500) is based on getting a kit and what we consider the bare minimum of supporting modifications (it doesn’t matter what kit your talking about). This also involves you installing the kit yourself. Add $1000-1500 if you’re having someone else do it.

 So, what do you need to do to make 450rwhp with your 3v? Put a blower on, that’s it. And it’s that easy. You can spend more money on go-fast widgets like headers, cams, etc, 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. 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 three things. How well it handles intake air temperatures, how well it grows (can be make more power in the future) and cost. Aside from how they look, that’s the only thing that will separate them when used in the real world.

The Next Step – 575rwhp

-Cost from stock to 575rwhp – $8,750-18,930

-Cost per horsepower from stock to 575rwhp $39-89 per HP

The costs above represents what it costs for the absolute bare minimum, which will not make 575rwhp in the real world, to a fully sorted combination that will give you no trouble and make full power all of the time.

Must Have Mods:

 

Forged Motor – $2,500-5,600

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

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 $2,500-4,500 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 $5,600 bill.

 Fuel System – $1,150-1,575

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 $1,150. 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 – $500-1000

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 $500. And another $400-500 for installation if you’re not doing it yourself.

Urethane Engine Mounts – $150-230

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. See the section on heads above

 Cams

No cams at this point. See the section on cams above.

What Is Our Suggested 575rwhp Combo?

This is what we would do for a 575hp combo (absolute bare minimum).

 Department Of Boost GT450-450HP

 -Department Of Boost GT450-450HP (with options)

-Manifold composite heat barrier option

-Urethane engine mounts

-Department Of Boost Super Single 22gpm Intercooler System Option

-FRPP 52lb/hr fuel injectors (stock 13’ GT500)

-S&H Performance DIY540 Fuel Pump Kit

-8 rib belt system

-Frankentensioner Belt tensioner

 -Clutch

 -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

 This will get you a system that will make 575rwhp all of the time and be stone reliable. We have lots and lots of customers who daily drive this combination as if the car came from Ford that way. This system can grow all the way up to 1000+rwhp.

 Why we chose this combo (no really, it’s not because it’s ours!)

 We chose this combo because to attain the same level of performance out of the other options it will cost you more money. And with a majority of those other options you can’t achieve the same level of performance no matter how much more money you throw at them. At the end of the day it comes down to performance/ dollar and if you put pen to paper our stuff unquestionably comes out on top.

 What are your other options?

 There are only two systems other than the Department Of Boost stuff still available for the 3v new. There are of course used systems, but that can be a can of worms. What is available and what do you get? For a very detailed description check out the sister article to this one 3v Positive Displacement Supercharger Buyers Guide. It has all of the facts, figures, etc of every 3v PD blower out there. After you read through the article you will come to the same conclusion we did. Our GT450 kit is the best option. It costs less and it has much better performance. In most cases the other options can’t match the GT450’s performance no mater how much money you throw at them.

Summary: 575rwhp

 The low end of the cost estimate ($8750) involves you starting with our intake manifold/intercooler and collecting the rest of the parts to complete the kit yourself. And you were really good at shopping for good deals. The high end of the estimate ($18,930) is based on getting a kit and what we consider the bare minimum of supporting modifications (it doesn’t matter what kit your talking about). This also involves you doing all of the work yourself.

 So, what do you need to do to make 575rwhp with your 3v? Build the motor, put a blower on, give it the right supporting mods, and that’s it. And it’s that easy. You can spend more money on go-fast widgets like headers, cams, etc, 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 575rwhp. The only big performance difference that you’ll actually notice is how they control intake air temperatures, which can KILL power if too high. A fair percentage of the blowers available can’t keep IAT’s under control at this HP level no matter how much money you throw at them (check out our 3v Positive Displacement Supercharger Buyers Guide for which ones). If you want to play at this power level anywhere but on a dyno you’re going to want to stay away from those blowers. If you don’t, you will never make the power you set out to. Other factors are how well the system grows (can be make more power in the future) and cost.

Things Just Got Real! – 650rwhp

-Cost from stock to 650rwhp – $15,500-40,000

-Cost per horsepower from stock to 700rwhp $37-106 per HP

The costs above represents what it costs for the absolute bare minimum, which will not make 650rwhp in the real world, to a fully sorted combination that will give you no trouble and make full power all of the time. There is obviously a huge swing between $37 and $106 per HP. There are a lot of ways to make 650rwhp work. Do all of the work yourself and shop for all used stuff on one end and drop the car off at a shop and have them do the entire thing with new parts on the other. You will probably land somewhere in the middle.

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. 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 most 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

 

 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 – $150-230

 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 – $600-3,100

 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 $2,2600. 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.

 Headers – $0-1,800

 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 $0-1,800. And another $500-800 for installation if you’re not doing it yourself.

  

High Flow Catted H or X Pipe (midpipe) - $1000-2000

 At these HP levels, catalytic converters have been known to come apart, block up the exhaust, and destroy the motor. You will need to run a midpipe (or you will most likely be going with headers and a midpipe) with cats that flow and hold up better than the stock ones. If you are only running the car at the race track you can save a pretty big chunk of money getting an off road midpipe (it has no cats).

 Cold Air Intake – $0-400

 None of the CAIs that come standard 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 standard 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.

 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.

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

Ported Heads

 Ported heads won’t make measurable HP. See the section on heads above

 Cams

 No cams at this point. See the section on cams above.

What Is Our Suggested 650-700rwhp Combo?

-Department Of Boost GT450 GenII

-VMP Ge3R Supercharger

-VMP 39mm Twin Jet throttle body

-PMAS 120mm 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” catted X or H 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

-Department Of Boost Titanic heat Exchanger

-Department Of Boost POWA intercooler water pump

-Department Of Boost 1.25” line/hose/fitting/plumbing kit for the intercooler system

 Why we chose this combo (no really, it’s not because it’s ours!)

 We chose this combo because to attain the same level of performance out of the other options it will cost you more money. And with a majority of those other options you can’t achieve the same level of performance no matter how much more money you throw at them. At the end of the day it comes down to performance/ dollar and if you put pen to paper our stuff unquestionably comes out on top.

 What are your other options?

 There are only two systems other than the Department Of Boost stuff still available for the 3v new. There are of course used systems, but that can be a can of worms. What is available and what do you get? For a very detailed description check out the sister article to this one 3v Positive Displacement Supercharger Buyers Guide. It has all of the facts, figures, etc of every 3v PD blower out there. After you read through the article you will come to the same conclusion we did. Our GT450 kit is the best option. It costs less and it has much better performance. In most cases the other options can’t match the GT450’s performance no mater how much money you throw at them.

Summary: 650rwhp

 The low end of the cost estimate ($15,500) involves you starting with our intake manifold/intercooler and collecting the rest of the parts to complete the kit yourself. And you were really good at shopping for good deals. The high end of the estimate ($40,000) is based on getting a kit and what we consider the bare minimum of supporting modifications (it doesn’t matter what kit your talking about). This also involves you doing all of the work yourself.

 So, what do you need to do to make 650rwhp with your 3v? Build the motor, put a blower on and give it a whole bunch of supporting mods. And get ready to break your wallet in half!

 Not very many of the systems out there can make 650rwhp. They simply don’t move enough air. All of the blowers except ours can’t keep IAT’s under control at this HP level no matter how much money you throw at them (check out our 3v Positive Displacement Supercharger Buyers Guide for which ones). If you want to play at this power level anywhere but on a dyno you’re going to want to stay away from those blowers. If you don’t, you will never make the power you set out to and end up doing what a lot of our customers do…….they buy their SECOND blower from us.

The Final Frontier - 700rwhp+

We actually have a complete 1000rwhp kit (Our 3v R Spec kit is even bigger than that!) on the site (call it 700-1000rwhp). And yes, a few people have bought it. It starts at $15,400. And you’re still going to need a motor, clutch, trans, driveshaft suspension, etc, etc, etc, etc, etc. And this will not be a bargain basement motor. Expect to spend at least $10,000-14,000. $5,000 for a transmission/clutch/driveshaft. At least $2500 in suspension. $3,000-4,000 in exhaust. And it keeps adding up. This is easily a $50,000 endeavor and that is if you do all of the work yourself. Can you do it in stages and work your way there? Of course you can. But have a plan and buy right. Or you will end up buying things 2-3 times.

There are probably 15 cars out there in this range. It’s not many. 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.

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 15 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 a 700rwhp+ 4.6L 3v 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!

Be Sure To Check Out The Sister Article To this One
3v Positive Displacement Supercharger Buyers Guide

And

You can see our other tech articles here

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

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?

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.