prop
From many discussions here I think there is consensus that the Q40 engine and prop is not suited well to the diamond dust, the whiplash or other q500 planes. The thrust is just not there. I have the nelson q40 turning 23500 on the ground and lauching is an experience every time and the top end is limited to about 180. Better selection is the q500 engines, jett50, jett45 ect. You need to turn a 8-9 inch prop.