LOL, Tyrel; a guy like me who has dumped on ad claims (myths)! Careful, the myth promoters will get ya!
Assymetric aircraft wings generate lift because of Bernoulli's Principle, the first part stated from our Turkish associate. The upper-wing air moves faster, therefore has less pressure (think of a perfume atomizer 'sucking' the smelly juice up). {That, there, is REAL technical talk.} Actually, the 'juice' is pushed up by the atmosphere's higher pressure, relative to the blowing air's lower pressure. The same pressure differential lifts aircraft at speed. (Sucking, BTW, is related to negative pressure,which has never been demonstrated; therefore must be another myth. LOL)
Sufficient airspeed to lift the craft is dependant upon the lifting characteristics of the wing and the aircraft weight. High lift devices, whether leading edge and/or trailing edge (devices) flaps, allow for slower flight speeds.
The lift produced is a mathematical product of a (test engineering derived) coefficient of lift, the size of the wing, air density, angle of attack, and the airspeed. Near-ground operations involve changing the shape and the size of the wings. High lift devices increase wing area and change the camber of the wing, which increases angle of attack, plus change the coefficient of lift with the 'new' wing shape. All of these increase lift, allowing for slower speeds for any given weight; safer, for many reasons.
How this applies to cars: the dirt guys use HUGE wings, which are effective at the lower speeds. NASCAR is very competitive, and teams must look for every tiny edge, whether the airflow characteristics improve downforce (cornering) or reduce drag, allowing more speed from the same power. Ricers and some others use wings as some kind of statement. I do recall my '63 split and many C-3's getting light 'up front' above 100mph. The balance point is sufficient downforce or the design speed while minimizing drag. ALL lift, whether positive, in the aircraft case, or negative in 'ours', produces drag; it is a byproduct, using the same equation, with a different coefficient (of drag).
The speed where any aero device is effective, relates to its size and shape. Car (and aftermarket product) sellers approach these items with differing levels of scientific support, PLUS looks that sell.
Some race cars looked somewhat like inverted wings. One even used fans to extract air (reduced pressure=more down-lift) from under the car. It was quickly banned. Most manufacturers are smoothing the undersides of cars to reduce drag (better CAFE) at highway speeds.
I can attest to the low pressure behind the windscreen of my BMW R1100RS trying to suck my helmut off, at speeds above 130. I doubt that most of us will feel much difference in lowering (or not) the rear of our Corvette by the amounts discussed unless and until we chase Moon across Nevada on his next race.
). He lost all control of the dragster and crashed big time.
