THK snow, I realize the Viper is TOO quiet in some respect. I like a little triple sound too. It isn't just top end you lose, it's all the way through. You really notice it when you have an identicle model sled to jump back and forth on. Yammadogger, the SRX's seemed to do just fine with a can, if they lost any power, it was minor. The Viper is a different animal. Yamaha did their homework on this stock exhaust and it's hard to do anything but add triples. I know, I've been down all the roads.........