ORIGINAL: foamcut
Bill,
I scanned a page from the August 2000 copy of the AMA magazine. In that article the author describes a 2 chamber design. he seems to indicate that the ratios between the chamber length as being critical to the design. I was unable to save a copy of the scan (pdf format) in my gallery. Let me know if you'd like a copy emailed to you. This might be information tha could be incorporated into a two-part Pitts design.....one more avenue to explore...
Foamcut,
I owned a Yamaha motorcycle dealership during the 70’s and watched many very skilled people experiment with 2 stroke exhaust systems.
The thermodynamics of muffler design for 2 strokes is very complicated and subject to much experimentation. The stock muffler appeared to have two chambers forcing the exhaust gas to travel further than it appeared.
Bill