I'm almost finished building my 81Z for autocross and one on the last problems I have is noise. My local autocross clubs are restricted to 92db measured from 50ft. I currently have a 2001 LQ4 with full 3" (tailpipes but no crossover pipe)dynomax ultraflows which is way too loud. Any way to get real quiet using cats or shorty mufflers in line or if I step down to 2 1/2" will it be quiet enough? Whos' measured their exhaust db's? I'd hate to dump a bunch of money into a new exhaust just to find out that I'm too loud and need to hack it up for another muffler inline, I'd rather do it to my current system.