RE: Little Toni w/ OS 95AX
very late reply...........
For a engine like the 91VRDF to get max power output you can't use more than 9" diameter props, otherwise your tipspeed will get too high inducing way to much drag.
@23.000 RPM the engine delivers 4.8 hp, at those kinds of RPM your tipspeed with bigger than 9" will approach MACH 0.9...........
Props usually used for these kinds of RPM are continuous strand carbon props. Normal plastic props are likely to disintegrate at this kind of revs.....
Just learned this lesson a short while ago myself through this forum as I've got a Picco P80 DF engine that gives 5.5hp @ 23.000 RPM, will put it on a Nemesis NXT made by www.air-c-race.de