I think you will find that the stock pipe is pretty hard to beat. Get an aftermarket can to shed some weight and also improve overall performance. I ended up selling my aftermarket pipe and went back to stock. Performance was unnoticable and fuel mileage improved drasticly. I went back to stock jetting. From what it seems, you have to jet up so much for the aftermarket pipes that you are just throwing fuel at it to keep it from burning down and then you battle bogs at some rpms. Once you get a can on it, start working on clutching and gearing. This will all depend on the type of riding that you do. Just my .02 worth. Good-luck.