I believe this is what Randall did...instead of cutting holes and welding a pipe between the inlet to the muffler and the muffler tips he drilled holes actually INSIDE of the muffler inlet. These holes allow sound to bypass any of the muffling material. The bigger the holes he drills, the louder he can make his muffler.
http://www.ppbb.com/boards/ppbbphp/showflat.php?Cat=&Board=ARCHIVES&Number=1085350&page=&view=&sb=&o=&fpart=all&vc=1
