Dick,, I really don't know what your trying to tell us here,,

first you say,, ""You can't reinvent tuned resonance""

well that may true but there is Exhaust Technology today that is NOT being used on today's RC gasser plane engines, ever cut in-half a Weston Heli Mini Pipe, or a Youngblood Heli Muscle Pipe (see link),,

inside the Youngblood heli pipe,,
http://runryder.com/fastphoto/38148/MP_1-3606.jpg


Dick,, so I know from my dirt bike days of the 70s and 80s and my RC racing boat days of the 80s and 90s and the last 8 years of flying RC helis that a 2 stroke is a 2 stroke is a 2 stroke, meaning there are many different types of exhaust that will pull power out of a 2 stroke, and what will work on a 8cc engine will "in larger form" work on a 40cc or 100cc,,

for the last few years Century has made different "heli" Tuned Mufflers for the Zenoah 23cc/26cc (see link). I'm sure these Century Zenoah heli mufflers are smoother and more powerful than a 26cc Inverted Side Muffler would be, yet these mufflers are not 26 inches long and not that loud at all,,,

Century's Tuned 23cc/26cc Zenoah Heli Muffler,,
http://www.centuryheli.com/products/...?currentid=210

I'm not asking anyone to reinvent a muffler for me, I just would like a slightly more powerful muffler that is not 26 inches long, after all those tuned heli mufflers prove the technology has already been used !!!

Jim