Ed,

Been there, done that. I've been building models since the late 50s, flying RC since 1970, and flying pattern since 1977. I am not rewriting history, but rather commenting on my own experiences in going from a Cutlass (muffled Enya) to a Kaos (muffled Kraft) to 2 Deceptions (piped Super Tiger, Webra, and Rossis) to a Tiporare (piped Rossi then YS) to an Escape (piped YS FR then YS longstroke) to a Cutlass(muffled OS 61 FX). The Cutlass performs far better with the modern engine and larger prop than did my old Cutlass, which was my point. And I have been impressed with the results of experimentation which has shown to me that I can get better performance in some situations by going to a larger prop than I used to use. The key is experimentation, as noted in one of my earlier posts. No single solution works best for all airframes and all engines.

However, I do agree with you about the noise factor. It is certainly possible to make pattern planes with pipes very quiet. My planes are almost always the quietest at the local field and I usually can't hear mine when another is in the air.

Jeff
Skylane N9214G
SPA 243