I recently had a vrx3 vengeance comp cam installed along with american racing headers (1 3/4) w/ catted y.i had a gmmg chambered exhaust installed also.the car at idle and slow acceleration has a unbelievable sound.my only complaint is under moderate acceleration at the 2500 and above rpm the exhaust gets raspy almost like the old cherry bombs sounded.the idle,slower acceleration & cruising exhaust sound is amazing.the best i've heard but the harder the acceleration the exhaust is loud and raspy.any way to eliminate the raspiness at the midrange rpm.i would greatly appreciate any input on this.i'll also post my dyno sheets for this setup which yielded 408rwhp at 6135 rpm & 367 rwt this was done on a mustang dyno at crt performance llc.there located in norwalk ,ohio.if i knew how to put my dyno videos on this forum i would put those on too.

 

I have heard it often has to do with the Y-Pipe -- you want one with a nice merge collector style... according to a local speed shop.