Just a quick note to tell everyone about my recent experience with the Q4. I was looking to replace the stock muffler as the previous owner had taken the baffle out of the stocker and I didn't care for the sound that it made. I had read to not expect too much performance-wise out of the Q4 but my experience says different. The bike runs simply awesome. I only have the baffle-less stocker to compare it to but the difference is night and day. The bike has more power....everywhere. It revs out better, has more pull and has a much cleaner response. It sounds great and is actually quieter at idle. By the way, i bought it off Ebay brand new for $260.00 shipped. P.S. only other mods are smog pump removed, Dave's carb mod and snorkel removal.