Barry ,
Sorry, as the 110 spins that prop fine at sea level and it's a real toss up with the APC 16 X 6 though. Between it and the 16.5 X 5W IMO it's a little better on spool up and control if that's the best explanation. I'm also running 20% nitro not 30%, so that can make a big difference. I know what you are dealing with at elevation and that is obviously a factor .

Mixmaster,
Problem is that a wood prop close to sea level will spin on the hub and actually smoke with the power of the mighty 110FZ, don't believe me, ask Acrojo . BTW, When are you going to pitch that OS 2 banger in the trash .