i currently run an FI system with 18" resonated exhaust and Z1 resonated test pipes
I ran at NCM Motorsports, that had sound at 103db and did not have any problems.
I also picked up some CC Inserts for street or track at the store there, they are Designed to meet race track sound requirements, I have not tired them yet. Got them because at some point I am going to get in trouble....
Since sound is becoming an increasing problem.
The web site is
www.carchemistry.com