Modified 07 Stock Mufflers
I'm new here, just thought I'd share with you guys my muffler mod on my 06 ZX-10. I liked the way the stock mufflers sound, especially at high RPM, I justed wanted it to be a little louder. So I bought a pair of 07 mufflers on ebay for $12 bucks (what a deal). I drilled the rivets, removed the entire insides. There is a thin layer of fiberglass mesh and wool around the perimeter of the case. I cut that off with a knife, and reassembled. Really made no difference in sound. I removed again and re-evaluated. Inside there is a baffle with two 3/8" holes to the next chamber. I got a long drill bit and opened them up to 5\8". I also drilled another 5/8" hole in the center of the baffle so I could see right through to the muffler exit. It is definitley louder, with more of a raspy, racey sound. My brother in law told me it sounds like a goddam rocket ship taking off when I do a fly by. Really no difference in performance, just sound, but for $12 and my time, what the hell.
P.S. I love this bike, it is my first ZX10. They really are marvels of modern engineering.