Intercooler System Requirements Specifications

What do you have now?

Obviously, it’s a good idea to benchmark where you’re at. There isn’t one single blower kit or car that comes with a blower on it that has enough intercooler (IC) system as standard. It goes from “it’s a little short” to “negligent”. The range skews hard toward negligent. These specs will mean something to you later down the page.

You have:

– 5-7gpm (gallons per minute) of water flow
– A heat exchanger with a core volume between 250 and 500cu in

What do you need you ask? That’s a complex answer with lots of qualifications/variables

– The first qualification is that you want your IC system to perform as well as your stock engine cooling system. For example, if your engine cooling system only allowed you to make a 6-8sec wide open throttle run before it started to overheat and kill power you wouldn’t be happy would you? That’s how 99% of IC systems behave. We can’t see setting the bar any lower than that.

– The second is that there are a zillion variables when it comes to cooling systems. In every single situation someone can say “Yeah, but…..(enter arguing on the internet here)”. We’re going to have to be ok with there not being any laser focused answers for everything in this tutorial because there will always be a variable someone can toss into the ring to “break” the solution. That said, what we have for requirements are really really tight. We have been collecting data/results for 15 years now.

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

– We test all of the pumps, line sizes, etc on a test rig we built just for that job. It replicates the engine compartment, the placement of each component, the hose lengths used, etc. We use the same heat exchanger and intercooler for every test (fitting size is adjustable). It’s as close as you can get to replicating real life without spending OEM level money testing. It is very easy to get different results by testing a different way. Remove the heat exchanger from the loop, you will get a higher water speed. Shorten the hoses and you will get a higher water speed. Feed the pump more voltage, you will get a higher water speed. Even changing where the intercooler is located vertically will change the water speed. Something as small as changing a few fittings from straight to 90deg will change the water speed. We test all of our stuff with the same variables every time.

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


You will see two different specifications in the chart below. Bare Minimum and Bulletproof:

-Bare Minimum. This is what we would define as the absolute bare minimum for most situations. This is a street car in a reasonable climate (“not reasonable” being Arizona) that is not getting hammered on all of the time and is not making repeated pulls. “A Sunday Driver” if you will. You’re going to see by the chart below that your standard system is going to be a long way from even bare minimum.

-Bulletproof. This one is pretty easy to define. Go pound your car ruthlessly. The IAT’s will stay down and will recover almost instantaneously.

What you may find

You may find that your manifold/intercooler is so restrictive that you can’t reach your goals no matter how many components and money you throw at it. That doesn’t mean that you can’t get much, much better results than you already have. For example, if you need 18gpm of water flow to meet your needs but you can only achieve 12gpm of water flow that doesn’t mean you’re doomed. You started at 5-7gpm, so making it to “only” 12gpm is a massive improvement. A 170-240% increase in flow/performance to be exact. That is a massive improvement you will notice and it will provide you with a significant performance advantage.

The Chart

Using the modifiers at the bottom of the chart calculate what your water flow and heat exchanger core volume needs are.

this is a chart describing the ways to calculate requirements - we are working to replace the image with a table,thank you for your patience while we make these updates to our website

Now what do you do?

Now that you have your water speed and heat exchanger specifications you go to the link below and figure out what combination of pump, line size and heat exchanger will get you to where you want to go.

-Start by clicking on the link that corresponds to the car/blower you have. Take a look at the chart and note what pump and line size you need to achieve your desired water flow.

-Then click on the heat exchanger specifications link that corresponds to your car/chassis (S197 or S550). This will give you a list of available heat exchangers, their core volumes and maximum line size they can take. It is very important that if you need to be running 1” or 1.25” lines to get your desired water speed that you choose a heat exchanger with fittings large enough. If not, it will not flow what you want it to.

Link to Water Pump/Line Size/Heat Exchanger Information

-Once you have the pump, heat exchanger, line size and maybe intercooler modification/replacement picked out to reach your goals you set on down the road of acquiring them. Of course, you would want to do it all at one, but that is not in most people’s budgets. So, they go component by component. Generally, it’s the heat exchanger first, then the pump/line kit and if needed the intercooler modification or replacement. Almost all of these items for your car can be found on this site.

If you are still a little lost after getting all of this data dumped on your head feel free to ask us for advice. Please email us with the model of your car, what blower you have, how much boost you are making and what sort of driving you do at



Intercooler System Requirements Specifications