How do i find the Rpm's of my motor
#1
How do i find the Rpm's of my motor
I'm trying to do the boost on my Rs and im trying to figure out the the full rmps of my motor
Its a 17.5 d3 the kv is 2300(please dont tell me me rpm is my kv otherwise ill feel stupid)
and i run a 2s 5000 is that matters.
Its a 17.5 d3 the kv is 2300(please dont tell me me rpm is my kv otherwise ill feel stupid)
and i run a 2s 5000 is that matters.
#2
Tech Champion
iTrader: (73)
There is no need to know the exact rpm your motor can spin till, with no load, you will see over 20,000, but for speedo programming purposes, use 11-13,000 as your end rpm, and start around 5k. This only changes when the speedo applies more timing, you can move the range around to find what feels best for your track.
#3
Actually, kV is the rating for how many RPM the motor will turn unloaded per volt applied, usually without timing advance.
So, the max unloaded RPM at 1s would be
2300 * 4.2 (full battery) = 9660 RPM
2300 * 3.7 (end race voltage) = 8510 RPM
On 2s:
2300 * 8.4 = 19,320 RPM
2300 * 7.4 = 17,020 RPM
When you add timing on the RS, the motor can turn more RPM than the kV rating would suggest.
On my 17.5 Boosted D3 TC, I usually run around a 6k - 16k RPM range, with a 6.0-6.3 FDR.
So, the max unloaded RPM at 1s would be
2300 * 4.2 (full battery) = 9660 RPM
2300 * 3.7 (end race voltage) = 8510 RPM
On 2s:
2300 * 8.4 = 19,320 RPM
2300 * 7.4 = 17,020 RPM
When you add timing on the RS, the motor can turn more RPM than the kV rating would suggest.
On my 17.5 Boosted D3 TC, I usually run around a 6k - 16k RPM range, with a 6.0-6.3 FDR.
#4
If you want to know exactly what rpm your car is doing at certain times, you'll need a speed gun, once you know the spped, you can work it out vis the diameter of the tyres and the gear ratio.
Skiddins
Skiddins
#6
Final Drive Ratio
FDR = (Spur / Pinion) * Internal Ratio
Example: my T3'11 has 38t diff pulleys with 20t center pulleys, and I use a 114t [64p] Spur with a 36t pinion for running boosted 17.5.
FDR = (114 / 36) * (38 / 20)
FDR = 3.167 * 1.9
FDR = 6.02
FDR = (Spur / Pinion) * Internal Ratio
Example: my T3'11 has 38t diff pulleys with 20t center pulleys, and I use a 114t [64p] Spur with a 36t pinion for running boosted 17.5.
FDR = (114 / 36) * (38 / 20)
FDR = 3.167 * 1.9
FDR = 6.02