by Chris Hunsicker » Fri Mar 17, 2006 11:41 am
I have a Holeshot that's been shortened by about 3 inches. It still has the steel perforated core, but all the fiberglass has blown out. I'm in the process of repacking it...
I've run it plenty without the fiberglass, and can't say its much louder. I don't know to what degree the core adds to noise reduction either.
As for performance, I doubt very much that running without the guts in your muffler will do much, as ultimately you are constricted by the diameter of your header pipe. If you switch all that out too, of course then you will prolly need to rejet your carbs...
Chris