One of the most important things for electric warbirds that a lot of people don't realize, is that the motor will not unload and increase it's RPM like a IC engine. You will not get the top end speed as you do with gas or nitro, unless you prop for it. Biplanes, high wing, aerobatics, 3D guys don't really care about speed, its all about thrust.
For the sake of argument, lets say a DLE35 will spin a Zinger 20x8 at 7150 on the ground, in the air the prop will unload and let the engine rev up to 8700 RPM. With no losses, an 8 pitch at 8700 RPM is 66MPH
Lets overpower the same plane with a big electric motor, say a AXI5345HD/14 on 10S. It should be able to spin that same prop at around 7200-7400 on the ground, and give incredible takeoff thrust. Once in flight, the motor RPM will increase as the prop unloads, but only until it gets to around 91% of its no load speed, or just about 7600 RPM. That's 57 MPH
IMO, this is were so many make the mistake with electric. Take that same motor, and put the 19x16 props EDFNUT is running, and you are close to 115MPH...with no losses. Put that prop on the DLE 35, and it won't run. In this case, a 10 pitch on the electric would give comparable performance at roughly 70 MPH, 12 pitch 86MPH prop speed.
I hope that makes some sense, but back to your props.
Second question, in the video I posted yesterday, are you looking to fly like I was flying between 2-3 minute mark? Faster? Slower? For reference, I wouldn't slow it down too much more than that. That was a 65 MPH prop speed, plane was probably around 55ish. When I did the fly by coming back across the field, after the failed landing, it started getting pretty mushy and I had to give it a little more throttle, I would say that was down in the 40s.
The 8 pitch props on the eflite 90s on 6S is 50MPH prop speed, or mid to low 40s plane speed
Last edited by 70 ragtop; 08-26-2014 at 06:27 PM.