BL system for a crt.5 on 2s

[rchippie]

Originally Posted by sleebus.jones

Yup, I second using the 5700.

I just did some calculations using brian's calculator & this is what i got. I did the calculations using a 12t pinion & the MM 5700 system.


Differential Ratio: 3.25
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 12
Total Voltage: 7.4
Motor KV: 5700
Tire Diameter (inches): 3.25 kit bow ties
Tire Ballooning (inches): 0
Motor Current Draw: 35
Motor coil Ω: 0
Spur/Pinion Ratio: 3.83 : 1
Total Ratio: 12.45833 : 1
Tire Circumference (inches): 10.21 inches (259.34mm)
Total Motor Speed: 42180 RPM
Vehicle Speed: 32.74 MPH (52.58km/h)
Effective Speed Rate: 4.42mph/V (7.11kmh/V)
Effective KV Value: 5700
Motor Torque: 0.04 ft-lbs
Final Torque: 0.54 ft-lbs

[lincpimp]

At that speed it will probably stay cool. I would say go with a feigao 7l, it will run well with those 8k packs and you could gear for more speed than a 5700.

[rchippie]

Originally Posted by lincpimp

At that speed it will probably stay cool. I would say go with a feigao 7l, it will run well with those 8k packs and you could gear for more speed than a 5700.

If i use a 7L it will take a very big pinion to get the same speed.

Ratio: 3.25
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 20
Total Voltage: 7.4
Motor KV: 3511
Tire Diameter (inches): 3.25 kit bow ties
Tire Ballooning (inches): 0
Motor Current Draw: 35
Motor coil Ω: 0.0059
Spur/Pinion Ratio: 2.3 : 1
Total Ratio: 7.475 : 1
Tire Circumference (inches): 10.21 inches (259.34mm)
Total Motor Speed: 25256.38 RPM
Vehicle Speed: 32.67 MPH (52.48km/h)
Effective Speed Rate: 4.41mph/V (7.09kmh/V)
Effective KV Value: 3413.02
Motor Torque: 0.07 ft-lbs
Final Torque: 0.52 ft-lbs

Which would be better & would 20t pinion fit if i decided to go with the 7L ?.


I've started my conversion by taking off all the nitro gear & cleaning the car. I have also made my battery box using kydex plastic. I will have to make a new top plate for the center diff & battery box brace. Im going to try to make it all one piece. this will also be used for mounting the ESC & RECIVER.

[lincpimp]

Well,

The feigao l can will produce more torque than the 5700 and allow for the higher gearing. You use of 2s batteries does demand a higher kv motor than is optimal. However the batteries you have are capable of 160 amps constant so it will not be too big a deal. Maybe a 6l feigao would be better. TBH you could buy the mm/5700 combo and try it out. If you do not like it, sell the 5700 motor and buy a 6l feigao. The 5700 motors sell well on ebay, so you should be able to get almost enough to buy the feigao motor. The 6l is about 4000kv, so an 18t pinion would put you at 35mph.