ORIGINAL: J Lachowski
18.1X10 on MTK's plane was a bit loud too for my liking. He tried a 17X12 as well, which I thought was much quieter and pleasing to my ears. I am one of those who is sensitive to noise and can usually hear a bad bearing a mile away<g>.
Also got to hear the 18.1X10 on a YS 170 CDI today which I thought was quite acceptable. Looks like the 18.1X10 is not the answer for the Syssa.
I agree with Joe that the 18.1x10 is a bit loud on the SAP180/ES30G pipe combo. I'll explain with back to back runs yesterday and today.
Yesterday I ran one of my hybrid props which a wood/carbon composite. This prop was exteremely quiet, on the ground and air. Frank Imbriaco was at the field and he commented to me how quiet it was. The prop is not quite there yet but I'm working on it....just a little too much for the engine on extended vertical (1500 ft), right now. Yeah I know, we don't fly 1500 ft verticals in pattern. To me, the power must be strong throughout the envelope so i have to test it to extremes. It is a wide blade configuration so that has quite a bit to do with the quietness as Bob has found out with his 15.5x12
Then I switched to the 17x12 and noise increased (surprise). The 17x12 wasn't what you call noisy, but it was noisier than the hybrid. The 17x12 seems to work well on my engine/plane so it's a good prop for higher speed
This afternoon I flew the 18.1x10 apc and the noise difference was considerable between it and the hybrid...I'd put it at around +2-3dB from where the hybrid was. Not sure if we talking 91-92 versus 88-89 but I would guess around there. It was also noisier than the 17x12. BUT, the 18.1x10/SAP is quieter than some glow set-ups I've heard in pattern.
Prop carving isn't for everyone, I totally get that..... We have off the shelf options though, so one can get in the air immediately