So where can I find the rules about what equipment is needed

You could put in an adjustable rev limiter. Set it lower at the track so you can't go faster than allowed even if you wanted to.

This would be the safest way. Better to not piss off the track guys by playing games, they have seen them all over the years.

And what pettybludart said. Some safety equipment you should have anyway. A helmet for example.

I am making my car slower and stock looking under the hood but I am keeping the scatter shield and drive line loop.