Drilled Stock Mufflers

Drilling the baffle plate in the stock mufflers is a very good and inexpensive way to obtain most of the so called "performance" slip-on mufflers. It is very easy to do and the bang for a buck is significant. There is a plate about a third of the way down each muffler that restricts straight passage of exhaust and forces it throught the baffles. This muffles the noise and also deals with many of the negative effects straight pipes have on this type of engine. I will not go into a discussion on exhaust design here as I am neither an expert nor do I have an inclination to become one. I will only say that according to my experience as well as many others' drilling a 1/2" hole in the baffle provides most of the performance gains obtained with an exopensive and loud set of slip-ons like Screaming Eagle or Cycle Shaks. I use a long drill bit, remove the mufflers and drill them from the "input" side. This makes me feel better in that the metal shavings from drilling will not make it to the engine somehow. The sound is almost stock, though a bit throatier and performace is excelent. I am sure you can do better on performance with aftermarket slip-ons, but bang for buck will not be there and you may not like the amount of noise that is constanly with you as you ride. If you are into loud pipes, this mod is NOT for you.