HPI Pro4 gearing
#1
HPI Pro4 gearing
Hi guys,
I am getting the HPI Pro4 kit, I will be racing 17T Spec class, but the manual syas nothing about gearing for 17Turn motor.
Does anyone here have idead about the gearing ?
plz comment
I am getting the HPI Pro4 kit, I will be racing 17T Spec class, but the manual syas nothing about gearing for 17Turn motor.
Does anyone here have idead about the gearing ?
plz comment
#2
I also driven 17t class. Gearing...it always depend on what is the size of the track? Is it carpet or asphalt? Tell more if you want some more info
#4
Hi Trinity2, nice to get some feedback.
I am running on a rather tight carpet track.
Handwound motor, 17x1 and 17x2.
Ill be using LRP Quantum Pro Sport w/4700 power cap and GP 3300 matched cells.
I was thinking of somewhere between 35 and 37 teeth pinion, plz tell me what you are using.
I am running on a rather tight carpet track.
Handwound motor, 17x1 and 17x2.
Ill be using LRP Quantum Pro Sport w/4700 power cap and GP 3300 matched cells.
I was thinking of somewhere between 35 and 37 teeth pinion, plz tell me what you are using.
#5
Originally posted by Snikkari
Hi Trinity2, nice to get some feedback.
I am running on a rather tight carpet track.
Handwound motor, 17x1 and 17x2.
Ill be using LRP Quantum Pro Sport w/4700 power cap and GP 3300 matched cells.
I was thinking of somewhere between 35 and 37 teeth pinion, plz tell me what you are using.
Hi Trinity2, nice to get some feedback.
I am running on a rather tight carpet track.
Handwound motor, 17x1 and 17x2.
Ill be using LRP Quantum Pro Sport w/4700 power cap and GP 3300 matched cells.
I was thinking of somewhere between 35 and 37 teeth pinion, plz tell me what you are using.
C`moon scoobydoo man...
At first i recommend you to try gears like: spur 98 and pinjon 35 = 6.83
That is what i liked to use our carpet track what is also technical and tight.
#7
Originally posted by 710baby
35 and up for large track tracks using 58mm trued tires
If your not afraid of cutting the comm alot you can also go up to 37-38
35 and up for large track tracks using 58mm trued tires
If your not afraid of cutting the comm alot you can also go up to 37-38
#8
Tech Regular
iTrader: (9)
When considering gearing always ask "What's your rollout?", by using rollout numbers you can tune for different size tires, different cars, etc..
Here's how to calculate it:
MMPR (MilliMeters Per Revolution, It's how far the car will travel in mm when the motor makes one revolution)
W= Wheel diameter in mm
S= Spur gear teeth (ex: 96T spur)
P= Pinion teeth (ex: 25T pinion)
For cars with internal drive ratios (Like a TC3 or a Pro4, it has an internal drive ratio of 2.5:1) Check your user manual for the drive ratio and add it to the above equation like so:
DR=Drive ratio (Ex: DR=2.5 for a TC3)
MMPR= (1/DR)*(P/S)*(3.1416*W)
Example: I'm running a 19T spec motor in my TC3, what pinion do I use. Guys at the track say that 25 MMPR is a good start.
I measue, W=65mm (full size TC tire), My spur is 100T
P=(MMPR*DR*S)/(3.1416*W)
P=(25*2.5*100)/(3.1416*65)
P=30.6
Round it off to 30T or 31T
Select the 30T or the 31T and try it out.
Ask people around at your track what rollout they use and you can find out your gearing with the above equations.
For a 17T motor on a fast flowing track I would use 30 MMPR to start, for a tighter track try 24 MMPR. Go up or down depending on on how you drive, the temp of the motor, etc..
Hope this helps.
Here's how to calculate it:
MMPR (MilliMeters Per Revolution, It's how far the car will travel in mm when the motor makes one revolution)
W= Wheel diameter in mm
S= Spur gear teeth (ex: 96T spur)
P= Pinion teeth (ex: 25T pinion)
For cars with internal drive ratios (Like a TC3 or a Pro4, it has an internal drive ratio of 2.5:1) Check your user manual for the drive ratio and add it to the above equation like so:
DR=Drive ratio (Ex: DR=2.5 for a TC3)
MMPR= (1/DR)*(P/S)*(3.1416*W)
Example: I'm running a 19T spec motor in my TC3, what pinion do I use. Guys at the track say that 25 MMPR is a good start.
I measue, W=65mm (full size TC tire), My spur is 100T
P=(MMPR*DR*S)/(3.1416*W)
P=(25*2.5*100)/(3.1416*65)
P=30.6
Round it off to 30T or 31T
Select the 30T or the 31T and try it out.
Ask people around at your track what rollout they use and you can find out your gearing with the above equations.
For a 17T motor on a fast flowing track I would use 30 MMPR to start, for a tighter track try 24 MMPR. Go up or down depending on on how you drive, the temp of the motor, etc..
Hope this helps.
#11
Tech Master
iTrader: (1)
Originally posted by ddesros2
MMPR (MilliMeters Per Revolution, It's how far the car will travel in mm when the motor makes one revolution)
MMPR (MilliMeters Per Revolution, It's how far the car will travel in mm when the motor makes one revolution)
you are in essence saying the "pinion gear" making 1 revolution since they are in direct connection to each other right?
#15
Registered User
I don't get it ... why ask a bunch of people who have never driven or seen your track advice about how to gear?
The best way to find out, is ask the fast guys at your track and then adjust the gearing 3-4 teeth up and down. Gear based on laptime ....
The best way to find out, is ask the fast guys at your track and then adjust the gearing 3-4 teeth up and down. Gear based on laptime ....