I forget the name but I had slide in open baffles in my last bike, made no difference in sound in or out but added the backpressure. They looked like the guts of a cherry bomb muffler that were held in by a bolt. Not much help but it worked for me.
2012 Victory Cross Country Tour, Sunset Red.
Parts added to make her louder, faster and more mine.
Stage 1 filter and pipes, Lloydz VFIII & ATW.
Clearwater Darla, LED GLO, emergency lights and siren.
Bushtec hitch and harness, Kompact Kamp trailer.