My long cannon pipes are 04 Speedmaster pipes with the taper cut off and gutted. I left the outer lining of mesh and packing as well as the reducer cone for some back pressure. Has a nice low rumble, not too loud unless I am hard on the throttle but can still hear it.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!