I have done this too. Had a friend at a muffler shop customize me a cat back with no mufflers. I only use this when i go to the track. Trust me...its loud. I have a few pics of it in my gallery too.

http://www.youtube.com/watch?v=3VhEGsJpcxA

http://www.youtube.com/watch?v=K32PlesuAd4

- Mike