what is the rule

what is the rule for exhaust header theaters?

You have to silence them once the movie starts?

Seriously, I don't understand the question. I guess I'm slow today.

I think, he is talking about tethers, and in that case, should be asking in the race section...not here in Q&A...

The general regulations say all removable exhaust collectors and parts must be secured by using an approved tether system, by being bolted to the body or chassis or by being welded together. I see no exception for slower cars.

They can also be secured by a "hanger" which is written to be a bolt on bracket. No one ever looked at mine last year, 4 different NHRA tracks. My bracket uses the 02 plug (or sensor) and bolts to the trans shield.
Doug