Good to hear this engine makes the same power on a pipe as the OS 160 makes on a Pitts muffler an 15% nitro spinning a 18X6 Vess which has equal load to a APC 18X6W. The power on a pipe is very similar to a Evo 26 on a pipe. In fact, if the Evo 26 was run on a 40cc pipe the power may be equal but I don't have one to try.

The Syssa on the stock exhaust and noise reducers spins the 18X6 between 8100 and 8400 based on posted reports.