I have an '02 Z28 and would like to get a new hood that has some performance benefit. Ram air hoods are relatively expensive for functional versions. Does cowl induction benifit our cars at all? If so, how would it compare to the benifit of the availible ram air hoods for our cars. PLEASE answer only if you know what you are talking about. I don't understand a whole lot about cowl induction, except for the fact that it allows hot air to be sucked out from the engine compartment by the low preassure created at the base of the windshield. Thanks in advance for your comments.

 

Cowl wont do much to add any horsepower to your car, but it will slightly help to keep your engine bay cool. It only work well on older cars that have the intake on the top of the engine rather at the very front which is in our cars. If you want a hood to help get you some extra ponies get a ramair directly into the intake, cowl will just help you keep the bay cool.

Mark

 

Here ya go!

Cowl induction takes air from the high pressure area in front of the cowl, but the pressure isn't enough to make any real difference, the gain is from cold air. The pressure is high enough to blow air through your heater intake...
What you were thinking of was hoods with heat extractor ducts like this . Again questionable whether there is any areodynamic basis for these reverse scoops to work, but the pressure under the hood would be enough to vent hot air out.