Also, keep in mind the comparison of pitch to the transmission in your car. The low pitch numbers could relate to the lower gear in your transmission. You use a lower pitch to gain power (poor word, trying to think of a better word but you get the idea), but at a slower speed. So, pitch down for more climb, for instance just like shifting to a lower gear to climb a hill. The engine will rev but the car (plane) will go slower, but have more pulling power. You can pitch down for a shorter take off distance, but your overall speed in the air will be lower, but pull on the elevator and the climb rate improves.

The opposite is true. Increase the pitch, your plane will go faster, but it will take a longer time to get there.. then pull to vertical, and you will lose that air speed more quickly as the engine strains to maintain. Take offs are longer because the plane takes longer to be pulled the take off speed when lift exceeds weight.

I've experimented with several props on my Venus II. I found that for my needs, with the OS 1.20 AX and Venus II combination, this combination really likes a 15-10 prop or a 16-8 prop. Both give me exactly what I want. And I maintain an operating RPM of right ar 9800 RPM at full throttle.

Hope all this helps.

DS.