I did the same thing with my 08 except just removed the rear baffle. The sound can changed some by adding different sized end caps. I am going to experiment with inserting a pipe the same size as the end of the pipe and making /changing baffles further inside so it still looks like a large outlet. You also need to change your carb jetting which will also give you more power, then you may consider opening up the intake areas, that is what I am working on this weekend. I just got a Dynojet kit #4148. When re leaving the factory back pressure you take a chance at burning valves which is why it needs to be richer mixture.
Keep in touch.
