ORIGINAL: DarZeelon
ORIGINAL: freakingfast
The use of the stock YS muffler will decrease the very high performance performance potential of this engine to the level mediocre 46 engine.
A performance muffler like the going out of business Performance Specialties ''Ultra Thrust muffler'' or the available Jett muffler are great but a tuned pipe is always gives the most powerful boost.
Karl,
NOT EXACTLY!
This would hardly be the case...
Please read [link=http://www.rcmplans.com/issues/requested/content/reviews/pdf/r-rv-ys45fs-051988-1-1.pdf]Clarence Lee's review from RCM[/link].
With the original standard muffler, the engine spun an original Rev-Up 10x6 prop, on 10% nitro fuel, at no less than 16,400 RPM.
The Rev-Up 10x6 prop is load-wise very close to the APC.
I can get the same numbers with a Super Tiger 45 and a TT46Pro on stock mufflers with the APC11X6 @ 12,700.
And the same #'s APC 10X6 @ 16350 on 10% and 15800 on FAI fuel with the TT46Pro and stock muffler! For me, Mr. Lee’s results are good, but not shocking.
If you have enjoyed the power of a tuned pipe on a YS 45 and than put a stock muffler with new best prop on it, you’d swear you’re towing a drogue chute. That muffler seems very limiting as far as it will let the engine unload from the higher static numbers. That engine has perhaps the most powerful response to a tuned exhaust that I have ever seen, the OS 55 AX is a close second.
The adapter block needed for the tuned mufflers will move the peak down a bit, no big deal, you just need to adjust the prop pitch accordingly.
I know these guys well, My YS 45 spares drawer: