Jammin CRT - middle diff

[lincpimp]

Here is the calc readings with your first setup with the stock spur:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 62
Pinion Tooth Count: 16
Total Voltage: 18.5
Motor KV: 1390
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0164
Spur/Pinion Ratio: 3.88 : 1
Total Ratio: 12.81731 : 1
Tire Circumference (inches): 18.06 inches (458.83 mm)
Total Motor Speed: 25715 RPM
Vehicle Speed: 34.32 mph (55.13 km/h)
Effective Speed Rate: 1.86 mph/V (2.98 kmh/V)
Estimated Adjusted Speed: 33 mph (53 km/h) - 4% loss
Effective KV Value: 1390

35mph is pretty good, especially for racing.

Here is the setup with the kyosh spur and 12t pinion

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 12
Total Voltage: 18.5
Motor KV: 1390
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0164
Spur/Pinion Ratio: 3.83 : 1
Total Ratio: 12.67949 : 1
Tire Circumference (inches): 18.06 inches (458.83 mm)
Total Motor Speed: 25715 RPM
Vehicle Speed: 34.69 mph (55.73 km/h)
Effective Speed Rate: 1.88 mph/V (3.01 kmh/V)
Estimated Adjusted Speed: 33 mph (53 km/h) - 4% loss
Effective KV Value: 1390

Pretty much the same as the stock spur.

[lincpimp]

Now if you step up to a 9xl, you can gear lower, like an 11t pinion. This will give much better performance, as the motor rpm is higher, right at 35k max, and the mechanical load is less due to the lower gearing. Plus you will pick up 5mph or so.

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 11
Total Voltage: 18.5
Motor KV: 1853
Tire Diameter (inches): 5.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0092
Spur/Pinion Ratio: 4.18 : 1
Total Ratio: 13.83217 : 1
Tire Circumference (inches): 18.06 inches (458.83 mm)
Total Motor Speed: 34280.5 RPM
Vehicle Speed: 42.39 mph (68.1 km/h)
Effective Speed Rate: 2.29 mph/V (3.68 kmh/V)
Estimated Adjusted Speed: 40 mph (64 km/h) - 6% loss
Effective KV Value: 1853