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Is there anyone that can answer this question with a high degree of confidence? - not hear-say or myth.
Why do we face a hood air intake to the rear and not the front?
Placement and aero engineering design in either case are the two primary considerations. A low-rise (like say the popular shaker designs used by Ford, Chrysler, and the rear-facing Pontiac) in the middle of the hood does nothing other than allow the engine to take in air outside the engine bay. Scoops at the leading edge of the hood or the base of the windshield are more exposed to the high-pressure air. Where you can place the scoop where ever you wanted, a high-rise forward facing scoop (like pro mod or pro stock) works best over the tall cowl hoods, anyway.
But you will always be design/law limited in a street application. In any case, it won't make much difference where the scoop is or what direction it's facing if you are thinking ram air. Just not going to happen in a practical sense. You have to change high-velocity, turbulent air into the stagnant, pressurized air a ram air system needs. There's just no effective way to do that from a packaging perspective on a street car. The plenum required has to be pretty big.
Im thinking your talking about 73 and up hoods, (if not disregard this post), theres a pocket of air that circulated in front of the windshield and thats what gets pulled in through the air intake, its "cowel induction"
Thanks guys, that's pretty much what I hoped to hear. Really appreciate your prompt response to my question. Searched the forum but unable to find a diffinative answer.
Cowl Induction - it works and it is used on every car
Although relatively few production cars use cowl induction to feed the engine, virtually every car on the road uses it... to feed the heater and air conditioner.
When a car is in motion, there is a high pressure zone of air that forms at the base of the windshield. This area is tapped to feed the car's interior ventilation system. And sometimes the engine, too.
Perhaps the most common (current) application for an engine's cowl induction is on a stock car (think NASCAR). The rules for most circle track (full bodied) cars do not allow a "hood scoop" or exposed air cleaner, so the air cleaner is fed thru a plenum / intake which is located at the base of the windshield.