At the track here in Montgomery they could care less. I could run 8's and they wouldn't mess with me. But, there's a track about an hour away that will check this kind of stuff. They require the use of helmets in any car even if you run 22's. If you plan to put your car on their track you will wear a helmet. It goes downhill from there...

It also wouldn't hurt me to have one. It actually could be of some use if my flywheel blew up.