RE: pipe question
3.5 Hp @17K rpm in a .65 is real optimistic. A Jett 90LX on tuned pipe, one of the most powerful performance sport engines ever made would have problems spinning an 11X8 @ 16000.
The chart shows the Rossi's best static power with a 11X8 is at 13300. If the prop is an APC that's 1.7 hp, actually not bad at that low of rpm. I would expect it to unload in flight at best another 1000 rpm.
They claim the highest power at 17000, so find an APC prop that loads it there with the best tuning on the pipe, once you do that it's easy to figure the HP.
I'm thinking you would be lucky if you could swing an 11X6 there.
That Rossi pipe they used in that test probably won’t be any better than any other brand of correctly sized chamber; it's all about tuned length.
No, OS won’t have any tuned muffler that would come close to what you want.
Insistently the pitch speed with an 11X8 at 14K is 106 MPH and at 16K its 121MPH, not that I think it will stay there in level flight after a dive with that prop.