Rear wings on cars
 

Hi Guys

Looking for some info on a rear wing on a 1/2 chassis car, as far as angle and depth of the wing.

Car details are as follws,

SBC chev, weight 2600pounds, rear tires 32/14/15 car runs 160mph for the 1/4 with a powerglide.

Any help would be appreciated.

Thanks

Kev

That is kind of a trick question. Wings are used for purposes. Down force and or smoothing air as it passes the body. The down force you get from a wing depends on area, angle and shape. You don't want more down force than what you need. It would be like picking springs/ shocks the wrong rate. Generally the down side of down force is drag. A wing can knock off a lot of MPH, but if your getting tire shake or instability you need just enough to stop it.
Frontal area is drag. The more angle the more frontal area. A wicker bill even an inch high can add 3 or 4 inches of unseen frontal area.

How the air that exits the rear can be very disruptive to handling. Every one has heard why turds are tapered, so your butt don't slam shut. That is why air should leave the rear of you car smooth. The slamming of air, buffeting, will give you bad handling. Everyone has been behind a semi on a windy day knows this feeling. It's the tail wagging the dog.

Every car needs different that is why funny cars have big scoops for down force and pro stocks have about straight just to aid buffeting and a little down force. The lower powered dragsters don't need the wing a AA/FD does.

Most bodied cars use their body and a spoiler as a wing, by limiting air going under car it creates low pressure. The curve of the roof promotes high pressure and the spoiler transitions air at exit.

A AA/FD is scratching for traction all the way down the strip. While 160 is a commendable speed for a stock bodied car, I doubt if you're breaking traction as you go through the traps. And, it is only at the top end that the wing will help at all. Also, the aero forces are proportional to the SQUARE of the speed. In other words, the force at 160 will only be a quarter of that at 320.

Sorry to be so pessimistic, but I think you can spend your time and money more profitably.

As an aside, I think it's time for the AA/FD crowd to start considering a full bodied car with a second engine to suck the air out from the underside. Or, has the NHRA foreseen this and banned it? That would be typical of their stand against improvisation.

Billy, I think that would be a good idea to create a downforce under the car. Isn't Can Am Cars already doing something like this with air channels underneath etc?

Trust me, doorslammers at times can benefit from rear spoilers or wings. I have busted loose many times at the other end and that was years ago. just two little wedge shaped spoilers made a huge difference for me.

I think that mostly what we are now seeing in drag race door slammer spoilers is creating more of a Kam Effect than it is a rear downforce.

Ed

That's right, Ed. CanAm, F1, Indy; you name it! Only in CanAm, however, was a "sucker" car built. Since it was so much faster than the rest, it was quickly banned.