Are you trying to make your own carbon exhaust? Repair one? Talk to the people at
Fiberglass , Epoxy , Composites, Carbon Fiber - U.S. Composites, Inc.. If you've never worked with fiberglass, I'd practice with that for economic and health reasons. The sanding dust is really bad for your lungs and carbon splinters like to come out the other side of your hand in a few years.
There's a lot of tricks to working with composites and making them structurally sound as well as look good. Buy a few books and read them twice. FOLLOW THE EPOXY RESIN INSTRUCTIONS TO THE LETTER.
You might make the can from fiberglass and put a layer of carbon over top for looks. Also line the inner diameter of the can with exhaust packing for insulation from the heat.
Ben