In Reply to: Drilling a hole in stock muffler! (more) posted by Bob ///M3 on September 16, 2000 at 11:05:46:
You know the J. C. Whitney car parts catalog? Many years ago, I saw an adapter in ther for a car's exhaust pipe. The adapter was to be inserted somewhere on the exhaust pipe, between the O-ring asbestos manifold gasket, and the muffler. The gadget had a flap on it, controlled by a steel cable, like what you'd use for a manual choke. By operating the cable, you could open and close a flapper, thus diverting the exhaust out, ahead of the muffler.
I imagine it was pretty loud. Also was a bit more elegant than using a drill bit.