Steve Millen put it best: Heat is the enemy. The compressed air coming from a turbo- or supercharger is too hot to pack into the combustion chamber, and as a result this spoils the efficiency of the combustion burn. A hot combustion chamber is also prone to detonation, which messes with the air/fuel burn and can punch holes in your pistons, and holy pistons are never a good thing. Elsewhere in your engine, oil that's too hot can shear and foam, losing much of itslubricating ability. When that happens parts rub together, and the resulting friction not onlydamages those parts but creates--you guessed it--more heat. And we haven't even gotten to the cooling system yet. When that gets stressed, the bad news starts with the radiator boiling over and can end at catastrophic engine seizure.
You can't avoid underhood heat; it's a major byproduct of internal combustion. What's worse, as you modify your car's engine to go faster, it's naturally going to generate--all together now--more heat.
Millen's racing experience has taught him a lot about keeping cool while making power, which is why Stillen offers a variety of heat exchangers--radiators, intercoolers, oil- and transmission-fluid coolers--in its product line. His was just one of a number of companies we spoke with to bring you the low down on keeping underhood temps on the down-low.
For tons of photos and all the specs of each product featured in our Engine Cooling Buyer's Guide, pick up the August 2006 issue of Super Street Magazine, on newsstands now!.