Are there any gains to be had if I cut the plugs ( round metal disk in the center of muffler pipes to direct air into baffles ) on a set of stock pipes, other than the sound? In the past I've always either gone with a totally different head pipe and mufflers or used slip on's. I've got a new jet and intake waiting for me to put them on an flht and was thinking I could install them and punch out the plugs in the mufflers until I get the dough for some slip ons.
I punched out the backs of the baffles in my lowrider (when I had it). Just took the slip-on's off, slammed a steel pipe down in (1 1/2" I believe) until it punched them out. Sound improved a TON actually, although the performance didn't really change that I could tell.