Quote Originally Posted by bada55mofo View Post
Really leaning towards the ISIS now, I want a RSR but don't want to spend that much on a used exhaust!
You are now looking at the wrong exhausts if you want quiet. Remember you want a 2.25" pipe for naturally aspirated or a supercharger. A supercharger is not going to significantly increase and will NOT decrease or muffle the exhaust sound if you go with a larger than 2.25" pipe. A 2.5" or larger exhaust will be louder and will decrease the performance of a supercharger. The m45 needs a bit of back-pressure to perform efficiently.