Is there some magical formula or some database to show what prop to use with what powerpack and airplane. Im flying with a c pack and wanted to try to get some more speed out of my bloody baron but dont know what prop to install to go a little faster but not melt anything. Im thinking of building a Mustang and have the same question for it.


Active member
Propellers are always a tough subject to explain. The higher the pitch of the prop, the harder it pushes against the air, and the bigger the diameter of the prop is, the more leverage it has against the air to push it. It's a balancing game of torque and RPMs.

I think the best way to figure out what prop to use with what motor is to look up what the motor itself is rated for. It's very easy to find this info online, especially if you're using a common motor.



Master member
Prop speed and I say this with a grain of salt will be faster then a large prop at less RPM`s. Think of large prop and pitch as being able to lug heavy airframes around, Larger planes usually have low KV motors for this reason small light weight will run high KV motors with small props if wanting more speed.....There is always a give and take when deciding on prop and motor of what you are wanting out of the airframe.

Having a Watt Meter to test props and batteries is one of the best tools to figure what prop works for what you are trying to accomplish, and they are cheap. I use mine all the time deciding what prop and battery combination works best with what setup.

Here are the results of one such test this was for a 3D plane where I was looking for the best combination.

motor Torque 2814-820 45 amp ESC
Prop Battery Amps Watts
12X6.5 3S 24 amps 270 Watts
12X6.5 4S 37 amps 495 watts

11X5.5 3S 24 amps 200 Watts
11X5.5 4S 30 amps 412 Watts

Even thou the 12X6.5 prop had more watts the plane actually flies better with the 11X5,5 being 3D it gives me quicker throttle response which is needed with 3D.
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