Intercooler Upgrade - A Cold Boost Of Power

When building a race car or a powerful street car, heat is almost always the enemy. After breaking into the 9s in the last installment of our AMSOIL GT, we decided to look at some of the underhood systems and see if we could reduce temperatures (namely inlet air temps and engine coolant temps), and find some extra power in the process.

In an effort to cool the compressed air from our Ford Racing Performance Parts 2.3L twin-screw supercharger, we decided to ditch the heat exchanger in the intercooling system in favor of an ice/water tank, which will pump chilled water directly into the intercooler. We know this isn't the most practical move for a street car, as once the ice melts the water in the intercooler will no longer cool the hot supercharged air. But we are looking to maximize track performance, plus everything we removed can easily be reinstalled in a short period of time.

Lastly, we removed the thermostat and replaced the factory water pump with a new electric unit from Meziere Enterprises, which will let us cool the engine consistently between runs at the track by allowing the coolant to circulate through the engine and radiator with the engine off.

The test is straightforward and simple--run the AMSOIL GT four consecutive times on the dyno, measuring intel air temperature (IAT), engine coolant temperature (ECT), supercharger case temperature, rwhp, and torque. With the stock FRPP heat exchanger setup, there was no service to do between runs. All we had to do was record all of the temperatures and let the ECT cool to our starting point of 190 degrees.

After all four runs were done, we disconnected the intercooler lines and attached them to the Stef's Fabrication Specialties ice/water tank and external electric water pump from Meziere Enterprises. With the ice/water tank installed, the test was performed again, but this time we refilled the ice between runs to see how colder intercooler water would affect IAT, ECT, supercharger temperatures, horsepower, and torque.

We were extremely impressed with the reduction in temperatures with the tank and pump underhood, as intercooler water temperature dropped an average of just under 49 degrees, which was recorded at the end of each of the four runs. All of the ice in the tank was melted, and the tank needed to be refilled each time.

Also impressive was how the other parameters changed. IAT dropped an average of 22.5 degrees at the end of the four runs, ECT dropped an average of 2.5 degrees, and the supercharger case even dropped over 5 degrees. These reductions in temperature netted us an average power and torque gain of just under 15 rwhp and 10 lb-ft of torque.

Next, we installed the Meziere electric water pump (PN WP342S), and removed the thermostat. This allows for less restrictive flow of coolant through the engine and radiator, with less parasitic loss. It also gives us the ability to cool the car consistently between runs, as well as lowering the engine temperature.

The installation was straightforward; we only ran into one issue. Our Ford Racing supercharger kit adds a couple of new brackets and idlers. With the Meziere pump in place, one of the idlers hits the body of the pump. The solution is a smaller (2.75-inch) idler pulley, which lears everything with no issues.

One the dyno, the results were impressive. With the ice/water tank packed, intercooler water temp stayed cold, which equated to very low IATs. Lower incoming air temps equal a denser air charger, which equals more power. For this set of tests, our IAT dropped to just under 97 degrees, which helped horsepower and torque climb to 638 rwhp and 524 lb-ft of torque.

With the ability to lower the coolant and intercooler temps more than ever, the car must be retuned to operate in the lower heat ranges. Once we make tuning changes, we're confident we will see significant horsepower and torque gains. We're excited to see how much power and e.t. is available by optimizing our current setup.

Looking at the data, the reductions in temperatures are fairly dramatic. However, all of our testing was done on the chassis dyno, and we know improvements will likely not be as significant on track, where you have burnout, staging, and run length, plus weather conditions and wind. The dyno is a controlled environment. Each run for this test was about a 4-second pull in Third gear. (Fourth gear would have yeilded higher rwhp numbers, but for the sake of the test, Third gear worked perfectly.)

Once we have the ice/water tank permanently mounted with the water lines run, we head back to the track to show you the real world gains.

Average Temperatures