I don't have any referance material on aero for cars aside the airfoil book but, I know that a great deal of attention goes into engine compartment openings and undercarriage aero on the land speed cars. For qualifying runs NASCAR crews tape closed all openings save a tiny one for the rad.
I have done a couple of simple pressure tests to see what areas were high or low . The obvious of course and some not so obvious. Low press areas were at the differential rear end hump, at the top of the rear bumper, just aft of the front airdam (but high there sans airdam) just rear of the leading edge of the hood to about 3/4 way back to windscreen on the Lotus but I suspect this would not be typical to some of the newer designs. Simple to do. Just some plastic tubing, duct tape, a simple manometer and a friend to ride along to read it. Tape the open end of the tubing where you wish to test. Not up to aircraft standards but very similar to what goes on in the wind tunnel, I suspect. One test involved running down the front straight at the old Ontario Motor Speedway. At about 125mph the pressure would rise a bit (on the side of the car closest to the wall) as I neared the wall up to about 6 inches where it suddenly took a drop. Perhaps that is the real reason Richard Petty always stayed so close to the wall(he said it was so he didn't have so far to slide when he screwd up). For me the best was mid course, away from the wall.
I was allways doing screwball deals just to find out "why" or "why not".
If Greg or someone else has some figures on engine compartment or underside drag I would be interested.
I keep reminding myself that aerodynamics in relation to race cars is NOT an intuitive science. Often what one would think works well, in fact does not.
Rod
PS---Isaac, in racing the mini, all this is just academic. It has the aero of a large brick!
