planecajun, Think about it....as a racer in the past let me correct you on one point.....pitch = speed. A fast giant scale race plane will be a bit slow getting off the ground, due to a high pitch prop which is more efficient at speed. These props don't really work well untill some time after the first lap when the air speed of the plane has increased. Our racer ran a 20x22, more pitch than diameter, for SPEED. Now my free style plane uses a 12x4 for pulling power, torque!! It is confusing, so you just have to get out there and try a bunch of things till it all comes together. But only try one thing at a time, and keep track of the changes, so you don't end up chaseing your tail.