I don't know how many people have heard of this but it was new to me. I am not going to ruin details by trying to explain it so I will just put the link. I think this is awsome for a race bike with no cat. I want it!
http://www.asphaltandrubber.com/news/buell-swingarm-exhaust-patent/
http://www.asphaltandrubber.com/news/buell-swingarm-exhaust-patent/