I raced non-winged Sprint Cars and entered some WoO events without a wing. The car was radically different, and had four-wheel independent suspension. I built a hood that gave quite a bit of downforce with minimal drag. It wasn't as fast as a winged car, but it wasn't as different as you may think. I am not saying a Sprint Car shouldn't have wings. I am trying to show you that what the wings are doing is probably not what you think they are doing. My opinion is the racing is better without them.

As with most aeronautical problems, with both race cars and airplanes, there is a whole lot more going on than initially meets the eye. The more you evaluate the problem, the more difficult the problem gets. In this case, a flat sheet of metal or a piece of plywood would work about the same as the wings on a Sprint Car. So, why go to the trouble of having a bottom surface of the wing other than for structural reasons?

Wind Tunnel Errors and Why
Wind tunnels will not accurately tell us how our wings are working. That is because the air in a wind tunnel is charged with energy from the simple fact that it is in motion and the walls and the ceiling are too close to the car. In most wind tunnels, the air is moving in excess of 60 mph. This means that the air possesses energy and air in motion will desire to stay in motion greatly affecting its physical movement as it flows around the car and wings.

In contrast, when we drive a Sprint Car into still air, that air has little or no energy. It is able to be pushed aside more easily and can move more quickly to fill the vacuum created behind objects such as the wings and the car itself.

It is this vast difference in the dynamics of still air verses moving air that causes errors in the evaluations in a wind tunnel. A more accurate way of evaluating your wings would be to do on-track testing utilizing the yarn tuft method I previously talked about and observe using a video recording.

Conclusion
Think about how your wing works and how you drive your Sprint Car. Top teams may have an edge here and have already re-evaluated their wing angles and driving attitudes. Watch the top teams as they race. If they crank angle out of the wings, they might just be looking for more, not less, downforce for tacky track conditions.

Higher wing angles might provide the needed bite on dry and slick tracks from more drag induced load transfer to the rear and that provides more acceleration that may be needed over top speed. With all of this new knowledge, you might need to re-evaluate your strategies concerning wing angles and placement. I hope so.