Looking forward to receiving the spreadsheet.

Thanks for the quick reply. I have a .40-sized Sukhoi with a cranky YS .53 that hasn't liked any prop I've put on it. Tried 12x6, 12x7, 11x7, 11x8 with no sucess. The 12" props were too much of a load, and detonation was a problem. The 11" diameter props ran well, but didn't generate enough thrust to move that barrel-nosed beast with authority.

I flew it this weekend with a Zinger 12x5 woodie I "discovered" in my flight box. Holy crap! The engine loved it, and the thrust was way up. Checking the numbers, the 12x5 falls right in between the 11x7 and 11x8. 12x6 & 12x7 load figures are way higher. More proof in action, I guess.