Well been lookin all over the NET and am actually seeing alot of systems without a muffler, 4" systems and 5"systems... is this goin to be ungodly loud... . well couldn't stand it anymore, so yesterday i broke out the sawzall and cut both mufflers off my 99... took it to the local exhaust shop and the placed a 3" (sorry mine is still stock) straight pipe, and to tell ya the truth it is NOT to big a difference... but I did notice the turbo spins up a little faster... just wondering if you went one of these other systems if you would lose to much backpressure on the turbo?? Any one running one of these systems i'd like to hear from... thanks Russ