gaRCfield,

Take a look at the Turbo-Jett in cowl muffler. It is a tuned muffler made 'Pitts' style to fit in a cowl. The normally long 'header' is coiled inside the 'can' with the 'stinger' at the bottom. Very cool design that will boost rpm.

Also, I've seen pics of full scale planes in Switzerland that have an 'after muffler' showing on the belly looking much like our RC models with a TP or mousse can/canister type boosted exhaust system.

Terry in LP