ORIGINAL: RVM
How on earth did you get 10300 RPM from an APC 14x6 with your Saito .82? With 25% Omega I peak my .82 at 9600 (with spinner, but I don't think it makes that much difference) on that prop. I'm at sea-level too.
Also, I get 8800 RPM from a Pro Zinger 15x4, which seems to put more load on the engine than the APC 15x4w. I once got the APC 15x4 to peak at 9660, but the best peak I've gotten since is about 9450, and that was on a bench. On the plane it's never been higher than 9200 RPM.
Either I've got a really crummy engine or you've got a really good one.
ORIGINAL: seanychen
Here it is:
Fuel, 30% heli, Wildcat Youngblood Mix
Temp: around 80ºF
APC 14x6 @ 10300 rpm = 9.5 lb
MA K-series 14x6 2nd gen. @ 10600 rpm = 9.25 lb
APC 15x4W @ 9700 rpm = 9 lb
Pro Zinger 15x4 @ 10300 rpm = 8.75 lb
Tachometer: Royal Tachometer
Thrust measurement is done by attaching a digital force gauge with an extension bar, hooking to the Sullivan tail gear brass collar on a Funtana 40.
All measurements are sustained reading, not the initial peak reading.
This confirmed what I found in the air, that APC 15x4W does not pull as well as APC 14x6.
If anybody has different thrust finding, please post. Thanks[8D]
What 25% fuel are you using? I think I tried it once and didn't really like it. Heli fuel w/ 23% low viscosity lube work great on Saito & YS.
If you get APC 15x4 to peak at 9660 on bench, then it's pretty much the same I got on that prop. APC 14x6 is indeed lighter load than APC 15x4W.
Pro Zinger 15x4 is narrower than APC 15x4W, and should get a few hundred rpms more than APC 15x4W, but not as high as APC 14x6. Maybe your setup on the plane is causing some variance. There is a quick fix though. Put on an APC 14x4W and rev it high. This engine seems to be more concsistent when it full-throttles above 10k.