ORIGINAL: Tangy Tom
Adrian, how did you find the downline with the WPN compared to the 18.1x11? How did they compare load wise? Sounds like the WPN is a lighter load. If the Japs are repitching them closer to a 12 then why not just use the 18.1x12? Its ashame APC don't do an 18.5X11.
I didn't care much about the 18.1x11, it slows the plane down too much, and you have to throttle up much sooner like a 2 stroke. As mentioned before, the re-pitched WPN takes better advantage of the torque curve of the 170. As for down line, it could be my idling is too high - around 8,050 to 8,1500 - causing a slight fast down line. I'm going to dial it down to 1,950 to 2,000 and try again.
As for why they don't use the 18.1x12, I believe one of the reason is the shape of the WPN. Believe me, I have sent a few of those 18.1 props to Naruke before the 07 WC, he actually came out with a 17.7x11.7 for the 170, and I have been using them last year before I received the re-pitched WPNs.
Adrian