Thread: Discussion Sundowner 50 fast setups
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Old Jul 27, 2012, 09:55 AM
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Oxnard, Ca
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Originally Posted by Madmax1965 View Post
I ran it up on 6s using an 11-5.5 prop...........Installed it in a Revolver 59(the small one). I do believe it is gonna be fast. I might need to go to an even smaller prop. I have had this motor sitting around forever and didn't have anything I could use it in. The stats say it will run on 6s to 8s but I don't believe it needs 8s and might run hot.

Thanks.....I will post the results later after I do a couple flights.

Hyperion tech said I could use it in their small 25e Mustang on 4s.......they said it would be very fast in that plane. So lets say 200 watts per pound .....That plane weight right around 3.5 lbs, so 3.5 X 200 = 700 watts. That motor is rated @ 1820 watts so I should be able to fly it like a rocket. Or I could go with a 40 size (around 7 lbs) and would be slightly underpowered as it suggest a 4025 motor -- although by the 200 watts per pound it should be OK.
Hey Mad,

XPC / Adrian started with a 890kv Hyperion back a while ago. He also used the 11x5.5 prop. He was pulling some crazy amp numbers on 6S, I believe 140A. I don't think you want to run the 11x5.5 on the 4020 910kv on 6S. My big issue with running an 11x5.5 is that your pitch speed is not too good, only at ~109mph, even though the prop is spinning at 20K RPM. Not useable IMO and really hard on the batteries (but thrust is awesome!).

I also toy'd with the idea of running a turnigy T600 880kv 5020 motor on 8S, but when I ran the calcs, I noticed that the motor / batts were going to get pushed really hard, so I went with a mid 400kv motor instead. I found that with the T600, the 9x7 or 9x8 would work, as there is a Jett 60 equip't SD50 a couple years back on a 9x7 APC doing 130mph and keep the amps under 100. Problem is a 9" prop on the SD50 will take forever to get up to speed but it will be easier on batts and motor.

I am attaching some calcs I ran on your setup, I think you should stick to your 6S batts since your motor is smaller for the useable prop range for the SD50. I tried running a simulation on 8S, but the calcs said the motor is unuseable in that range. Note, 6S and 10x7 prop might be your best bet, it would be what I would choose as it has good thrust and 122mph PS. Should get you over 100mph.

Good luck!
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