Originally Posted by LACSTER
There's a big difference in sound between the two. I really like the M5 much better it feels more open and does not stop back pressure. The sound is a lot tighter and louder as well. I opened up the vacuum hookup to open position and locked it so all pipes are working. When the vacuum was closed the sound was very close to the M6 exhaust.
thanks! any drone with either setup? also did you remove secondary cats?