See those two washers I put in between the exhaust piping flange? It lets some of the sound escape through there. Most of it still goes thru the muffler so it still sounds the same...this just adds some depth to it. I did a lot of expermineting with different gaps and this was the perfect balance. Do this to only one of the bolts on the flange. If done to both, it will be too big of a gap, too loud and will change the exhaust tone. I used 2 washers...1/16" thickness each. So total 1/8" gap.