compared to my NA w/o mufflers :) and hearing detonation was clear as day. I believe we have it on camera. You can definetely hear the ping, marble in a tin can or whatever you want to call the sound over the exhaust. Even Ash when he was in the car could hear it.
Kai 14.765 @ 92.22m.p.h. #4 in 2002 on Z32racing.com in NA drags (206.4 RWHP)