gearing for medusa
 

Hello I have a kyosho kanai converted to electric with Mamba Max esc+ ubec + 4s zhippi 5000mha 20c and medusa 2000kv 60mm. What gearing can I use? I have pinions of 13t, 15t, 17t and 19t, my spur is 46t and mys diffs are 43/13
Regards

I would start w/17 and check temps....that way you can go either way w/gearing

http://www.scriptasylum.com/rc_speed/_top_speed.html

As seen, a 17t pinion will yield you 37mph

A 19t pinion will yield 41mph

In my calculation it is different, on 17/46 :
Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 17
Total Voltage: 14.8
Motor KV: 2000
Tire Diameter (inches): 4.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.006
Spur/Pinion Ratio: 2.71 : 1
Total Ratio: 8.95023 : 1
Tire Circumference (inches): 14.14 inches (359.08 mm)
Total Motor Speed: 29600 RPM
Vehicle Speed: 44.27 mph (71.12 km/h)
Effective KV Value: 2000

on 19t: 49.48 mph, on 15t: 39.07 mph and on 13t: 33.86 mph

Regards

i use the 36 60 2000 motor in my buggy on 4s and it has the 43/13 diffs. i am racing it on a smaller indoor track and using a 14/44 setup. it has really good power and runs cool at 110 after a 5 minute run but the indoor temp is only around 55 to 60f.
running it outdoors on larger tracks i will try a 15 tooth if it dosent get too hot. honestly it has great racing acceleration and speed with the 14 tooth.
i would think a 17 tooth will get you into trouble. also those gearing charts are misleading at times. when i had my novak 6.5 system in my car i clocked it at 37 with my radar gun. i havent clocked it with the medusa and 14 tooth but i can tell you it is faster i would say 40 or a shade faster.
always gear your car so it runs at a pace you can handle but most importantly dosent get the system hot.