The engine comes with a large muffler. From some accounts, it is apparently quiet enough.

But in this pattern forum we discuss tuned pipes for the most part. I doubt many will use the included muffler for pattern planes....could be a bit too bulky to fit the front end of most pattern types.

Talking tuned silencers, I just purchased a tuned exhaust (header and pipe) for the Mintor 38 cc from Area 51. The price was terrific so I couldn't pass it up. This same pipe will work fine on the 33GT. The header will not since it is the 4 bolt type intended for the Mintor. The pipe is only 1 ounce heavier than the ESComposites and is aluminum. The reflector ring is located at the same place as that of the ESComp......