what's your x-pipe setup? Did Akra make a DB claim on their product?
I've seen at tracks if the car was too loud, people put that bent pipe adapter on their pipe to clear the restriction where they measure the noise, it basically directs the noise away from the measurement area. it's a custom piece, and these guys are making it on there:
http://www.nsxprime.com/forum/showth...dB-noise-limit
don't laugh, but it looks like this:
I've seen it at Road and Track Live! driver event where they stuck it on a F430's tail pipes.
Alternatively, it's probably just easier to let up the throttle in the measurement areas. lol