ORIGINAL: cmoulder
Matt,
I tried the 17x12 on mine and it was just a teensy bit too much. Interested to see how yours performs today.
Close to 90 degF and humid today (as you no doubt know!!) and didn't touch the needles. Excellent performance with the 15.5x12W - identical to when I tuned it with the temp in the low 50's, again in the mid 70's and now today. Good pace with the plane, still unlimited vertical and not a hint of overheating. The buttonhead screws on the header were the last piece of the header/coupler/pipe puzzle. Rock solid.
Finally, a bulletproof set-up! This puppy is dialed![sm=thumbup.gif][sm=thumbup.gif]
Bob,
Great stuff!!
The 17x12 was tried on 100LL Avgas with DelRey 50:1 synthetic. Once the needles were reasonably close, I took one whole flight and did do one extended vertical just to see. Engine is not fully run in by any measure but it held well for probably 600-700 yards straight up...practically no sagging to speak of. I also did some higher G stuff on shorter verticals, like multiple snaps. Nothing out of the ordinary noted. Behaved like a well tuned glow set-up
I think that the fuel and set-up need just a bit more tweeking.... we are nearly there. I also think that we may have found a way to get more pop in mid range...., we might be able to run a fatter midrange and get the pop we want with higher Octane gas. I'll tell ya I having a ball with this ignition stuff