bjanzen

iTrader: (6)

Okay..... Thanks for the help. I don't have a collection of gear oils so I built one of my gear diffs with Lucas oil stabilizer. Not sure where it falls in the range of fluids...... Feels tighter than my ball diff but certainly free compared to 500k silicone. Hoping to try it before I leave for the 'birds.......

YR4Dude

iTrader: (44)

Be careful when using automotive stuff in RC. Some of that stuff is not designed to run with plastic components and will eat plastic. Stick with fluids that are made for RC use to avoid trouble.

Cole Trickle

I cant help but wondering if "adjusting the diff" really is a tuning option? I mean, I've heard about 1:1 4WD which can lock the diffs, but thats for the purpose not getting stuck in the mud. I dont recall having heard about a 1:1 Rally car or Touring car, which used the diffs as a tuning option? Also, several tuning guides for RC cars dont mention this as a option?

I dont say it dont work in RC TC's, I can feel the effect, but I cant help but thinking of this as a shortcut, because it's easier than to tune the other settings?

Cole Trickle

To answer my own question: Several 1:1 cars uses various kind of differentials, often it's LSD (Limited Slip Diffs) or even active differentials, which can be changed by the driver. Mitsubishi Lancer Eco, Ford Focus WRC and Mercedes 190 are some of those cars.

Anyway, about 10 years ago, one of the arguments to upgrade the HPI Sport2 gear diffs to ball diffs, were that they were lighter. The lower rotating mass should be good for acceleration. Are modern gear diffs still heavier than ball diffs?

Skiddins

Xray's T3 gear diff is 10g lighter than the standard ball diff!

Ahh, the benefits of modern composite components and manufacturing techniques

Cole Trickle

Nice !

I'm not keen on RC maintenance, so I love LiPo and BL - and I'd like to get gear diffs as well. Dont think there's gear diffs for my Schui Mi2, at least not in the rear. Gear diffs would also take the joker "is my ball diffs adjusted eaually" out of the equation. Dont think I'll get a new car any soon, but when the time comes, Xray T3 are now high on the list

YR4Dude

iTrader: (44)

With fluid or without fluid?

stiltskin

iTrader: (103)

Did some more testing today. Ran dual ball diffs to see what they felt like. (insert barfing emoticon here). Car was ok lowspeed, very lazy through the chicane, and pushed on power. Put the gear diff back up front and the car was good again. Back end was planted with the ball diff in the rear and car was very predictable. I'm still convinced that the gear diff in the rear can be made to work in every situation. Switched from 40wt oil to 100wt oil and finally got a similar feeling to the ball diff on the track. Car was predictable and rotated well. Race day tomorrow, we'll have to see how it goes.

Cole Trickle

Very interesting stiltskin, thanks for sharing

Qatmix

Are you running foams or rubber on carpet?

I run my car on foams and Ball diffs front and rear are the std. I've moved over to gear diffs and the car feels more aggressive.

I ran it with 900 front and rear but it was too light.

I am now trying 2000 front and rear and the car (417) is really starting to feel planted.. I need to refine a few parts of my set-up before I am going to change the oil.

Skiddins

With.

If I recall the oil weigh's 1.6g
Completely ready to run!

stiltskin

iTrader: (103)

Not sure if this was directed at me or not. We run rubber tires on carpet right now. I haven't run foam tires in a few years, so I can't comment on gear diffs with foam tires.

TQ'ed today with 37/6:08. Fast lap was 9.724. Average was 9.962. Worst lap was 10.9 after I caught a flapper. Car was very easy to drive and still turned in very well. Our track typically loses traction throughout the day and the mains can be tricky. My car was working very well with the 100wt in the back until some point when I lost the lower screw from a steering knuckle. Very happy with the results of the dual gear diffs today. I'll be putting a spool back in the front for more comparison next week.

lethallee69

iTrader: (17)

With a spool in the front, what tuning difference is there between light and heavy oils in the rear gear diff? ie; does a heavier oil give more/less steering etc
Running on a medium traction flowing asphalt track

jake95

iTrader: (27)

Lower CST oil for lower traction tracks higher cst for higher traction tracks Paul l's said
500cst low grip
1000cst medium grip
2000cst high grip
3000cst super high grip
Seems when I went a little bit harder cst I did notice a difference but not by that much if oils to thick you will have no rear grip.
Jake

angus

This thread definitely has me wanting to try gear diffs now... after just buying ball diffs.