If you want a bolt on performance pipe, the only option is a Jemco pipe for about 200 bucks with shipping. Even then you have to have the mounting brackets welded on when you get it. I had a killer pipe made from a Kx65. A buddy of mine cut and welded it for me. I used the manifold pipe from the stock exhaust, and the brass bushing from the header pipe off the trizinger I cannibalized. Total cost was only 55 bucks. I've also used a bi-turbo exhaust in the past from 1977mopeds. Cost is about 80.00 bucks or so, but then again, you'll have to manufacture a header pipe.