buggy differential question..need some opinions.

[skellyo]

51T isn't large for a spur gear...why do you think you need a lower tooth count spur gear?

[DwightSchrute]

Originally Posted by skellyo

51T isn't large for a spur gear...why do you think you need a lower tooth count spur gear?

Originally Posted by snellemin

My GTP uses the same diffs and spur as the LX and I use the plastic 51T spur and still am plenty fast.

we all own 1/8 buggies, and in the summer we run them at our track, and we do gear it down for the races, but it's a different story when the track is closed..

during the winter we all put in diff lockers and go pavement running. most of us are running 43/24-25 and 44-46/24-25 on 6S. we have a HUGE abandoned walmart parkinglot here where we just chase eachother around and do speed runs.

i'm concerned that the lx-1 won't be able to keep up geared 51/25, and it's no fun if you're the slow guy.

Originally Posted by lincpimp

The bearing dimensions are different for the ultra series compared to most other 8th center diffs. Good to hear they have fixed the diff gear issues.

thanks for checking into the compatibility, lincpimp. anyone have any other suggestions? i even thought about oversized pinions from SDPI, but i'm not even sure the motor mount has enough space for a 30T which is the next available size from 25 or 26T from them, i think.

[skellyo]

Originally Posted by DwightSchrute

we all own 1/8 buggies, and in the summer we run them at our track, and we do gear it down for the races, but it's a different story when the track is closed..

during the winter we all put in diff lockers and go pavement running. most of us are running 43/24-25 and 44-46/24-25 on 6S. we have a HUGE abandoned walmart parkinglot here where we just chase eachother around and do speed runs.

i'm concerned that the lx-1 won't be able to keep up geared 51/25, and it's no fun if you're the slow guy.

So let me get this straight...you're running a 2650kv on 6S and gearing it for ~120mph?

I'm quite surprised you haven't melted your motor several times over already. A ~6:1 FDR in a 1/8th buggy is going to put stupid amounts of load on the motor.

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 25
Total Voltage: 22.2
Motor KV: 2650
Tire Diameter (inches): 4.3
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0.0035
Spur/Pinion Ratio: 1.84 : 1
Total Ratio: 6.08615 : 1
Tire Circumference (inches): 13.51 inches (343.12 mm)
Rollout: 2.22:1
Total Motor Speed: 58830 RPM
Vehicle Speed: 123.65 mph (198.63 km/h)
Effective KV Value: 2650
KT constant: 0.51 oz-in/A

[DwightSchrute]

Originally Posted by skellyo

So let me get this straight...you're running a 2650kv on 6S and gearing it for ~120mph?

I'm quite surprised you haven't melted your motor several times over already. A ~6:1 FDR in a 1/8th buggy is going to put stupid amounts of load on the motor.

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 25
Total Voltage: 22.2
Motor KV: 2650
Tire Diameter (inches): 4.3
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0.0035
Spur/Pinion Ratio: 1.84 : 1
Total Ratio: 6.08615 : 1
Tire Circumference (inches): 13.51 inches (343.12 mm)
Rollout: 2.22:1
Total Motor Speed: 58830 RPM
Vehicle Speed: 123.65 mph (198.63 km/h)
Effective KV Value: 2650
KT constant: 0.51 oz-in/A

actually, you're not far off. most of us have already gotten over 95mph and a few of us have broken 100mph when it was a bit warmer with the grp rally tires.

Originally Posted by snellemin

hmmm, the next thing will be making a custom hub for the solid diff option(OFN33020), so you can run smaller traxxas spurs. This is what I'm going to do with my GTP.

excellent idea. i'll look into that. thanks a bunch!