I just finished bolting on a set of Yosh Carbon Fiber RS3 Race cans on my new '05. I did not mean to do it, but I went into Star Cycle in Canyon Country CA and the sales person had just put a set of the same cans on his new '05 and he assured me that they did not backfire and that the bike still ran just fine. And then, I realized that the carbon fiber would match my grey bike perfectly. And, I wanted a little more exhaust note than stock. Next thing I know I was heading up to Frazier Park in my Mustang to pick up the cans at Star Cycle's warehouse, and my wallet was much lighter since I ordered some Heli-Bars too, which they will ship to me next week. So mods are: centerstand; Yosh cans; and bars to come, all in the first week. And, I promised NO mods on the Busa.
Anyway, the Yosh cans are pretty loud by my standards, but they do not backfire, and other than a little hesitation right off idle, they seem to work just fine with the stock tune. Now the bike sounds like it has some power. I will take a pic tomorrow if I remember and post it since IMHO, they look really sharp with the color of the bike.
