oXYnary

iTrader: (4)

This is in the context of 1/10th and smaller electric 4wd off-road Racing. My background is more electric racing and I missed/ignored most of this Nitro Truck craze the past 8 years. So Im trying to figure this out.

I know Viscous/Fluid Differentials are used in 1/8th scales and many basher trucks (even some 1/10th nitro pro sedans). I understand the principle that the fluid gives, but is there any reason Ball diffs aren't used? In that large a scale they fail? I know many Nitro people swear by them, but I keep wondering if thats because Nitro needs them versus being a inherently better technology. In which case, with todays brushless and insane powered brushed, why wouldn't Viscous used also? Or is it because a Nitro gains more torque with RPM while a electric looses.


Here is my ?misinformation?

Viscous:
-Extremely durable
-Can be adjusted with high weight oils and left for months.
-Oil gives tiny bit of dampening effect (alah Losi Hydra Drive)

Bads:
-Weight
-It would seem necessary to run a slipper clutch to help sustain the drivetrain in a electric 4wd since other than a dampening effect, it has no traction control? (Does the clutch and middle diff partially make up for this on 1/8th gas?)


Ball:
-Light
-Can be externally adjusted
-Allow tiny bit of slip under high strain conditions/punch

Bads:
-Rebuilding more often
-Backing off/break in
-No dampening effect on landings (but some very very suttle slipping).

gubbs3

iTrader: (7)

I kind of in the opposite boat that you are. I have raced 1/10 nitro trucks for many years, and hardly any electric. I just started racing carpet this winter btw. I am not going to come accross as a not-it-all but lets just look at the types of cars that use ball vs. gear diffs.

Ball: all quality 1/10 scale 2wd on and off road, most 4wd 1/10 electric.

Gear: 1/8 nitro, monster trucks,...

Even if I missed a few you get the idea. High power, high stress vehicles use gear diffs. They can take the power with minimal failure.

The diff is probably the most important setup tool in any class of vehicle. If you have a poor diff setup, there is no tuning around it. I think the decision for what type of diff is exclusively chosen by the smoothness and consistency vs. durability.

oXYnary

iTrader: (4)

So would you agree then that a viscous gear diff allows some adjustment and has the benefit of extreme durability. But compared to a ball diff if possible, lacks the fine tuning?

You have to note, that 1/8th buggies and 1/10th sedan competition nitros use viscous/oil diffs. At least the 1/10th, I cant see why. So what is the draw for competition racing? Why not use a ball diff if possible if they are inherently better?