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Originally Posted by Bisimoto
I did use a fan in 2 areas: the front for the heat exhanger/radiator, and the rear driver's side vent, but only to provide cool air. A single cylinder in our P-car engines demands air at 2000RPMs that none of my industrial grade fans can generate. As a matter of fact, a NACA duct (superior to our Porsche side vents) is only efficient as a ram at above 200mph.
2 weeks ago i performed a test using a fully radiused intake pipe on single cylinder induction tubes, and gained 12whp on a 320whp engine. Infusing such technology in our induction may prove benefitial, but the factory ram tube, incorporated with the "deflection cup" is a restriction, and hence, the power gains seen in the upper RPM range.
Thanks for the suggestion...great minds think alike!
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Hi,
As someone who did their thesis on NACA duct research, I can tell you that you are somewhat correct so far as Ram Effect is concerned. In fact, a Ram Effect is not achieved within a NACA Duct until transonic speeds are reached (about 0.8 mach, or approx. 609 MPH).
But, this isn't why NACA ducts came into widspread use in motorsports. It was because of a reduction in drag over previously used protruding intakes. This reduction in drag, not achieving a Ram effect, is what made them desireable...
Happy Motoring!... Jim'99