[kyleb]

Originally Posted by guye

The VE cats make a big difference, so that's a start. On my undercar system I had VF cat, one muffler (straight through) two baffle plates and three steel wool balls on each side and the system is 2.5" stainless pipes. That kept it under 90db each side as required.

Sorry, I know that's not exactly helpful for your sidepipes, but the baffle plates and wool balls might help. Are you after temporary of permanent notice reduction?

And be careful not to overheat your 'wool balls'
That would be bad !!