Diff oil weight

[islandlife]

For anyone running their sct’s on outdoor dirt/clay tracks, what are you running for diff oil weights F/C/R?
The manual for my AE pro4 sc10 calls for 60/100/3, which seems really thick in the front and center compared to any of the stuff I've read on the internet.
I've ran all sorts of weights, but have not settled on anything.

 

[Smilinbri]

I've tried lighter and thicker. I prefer the lighter and will be putting lighter fluid (no, not the flammable stuff ) back in my 3s Senton and Traxxas 2wd when I do my winter maintenance. Gotta experiment with it. I prefer the tighter turns and found that on the dry/loose dirt on my track, lighter is better....for me.

Senton 3s-last season had 30/20. Currently have 50/30 and don't really like it.

Traxxas 2wd....last season had 60k....now have 200k.....not as bad in a 2wd....but I prefer the 60k.

Tekno I built this past winter has 10/7/5 and lovin' it.

So yea, I'd def go lighter.

I found this info on the Arrma Forum that helped me understand it all better. Good luck!

 

[Lumikko]

For anyone running their sct’s on outdoor dirt/clay tracks, what are you running for diff oil weights F/C/R?
The manual for my AE pro4 sc10 calls for 60/100/3, which seems really thick in the front and center compared to any of the stuff I've read on the internet.
I've ran all sorts of weights, but have not settled on anything.

Thicker fluid in the front adds on-power steering and helps against diffing out the inner front wheel.

Thinner fluid in the center diff helps maintain control when you accelerate hard and the traction is on the low side. It also helps control hard braking.

Thinner fluid in the rear also helps on-power stability when traction is low. Thicker fluid in the rear helps off-power stability but reduces rotation into corners.

These are just a few of the effects as I have understood them. Changing things from the stock setup should be done as a means to make the truck do something it doesn’t do for you now. Understanding the setup changes helps a lot more than referencing other people’s setups.

If you haven’t opened up your diffs before, it might be a good idea to put the stock 60/100/3 in there to get a feel for what it’s supposed to be in the first place.

 

[islandlife]

To be clear, I've read through several guides and whatnot explaining the effect of changing oil weight in the diffs. And have run several different variations in my pro4, ranging from 60/100/5 to 10/5/5, and several combo’s in between.
So far with my testing on my track i think i prefer something around 30/30/10 to 20/30/5. But still experimenting.
It just seems when reading through various setup guides that in the off-road buggy/truggy world the diff weights used in racing are much much lighter than what is called for in the manual. I.E. 5/7/3 or 7/10/5 etc.
Is this a product of vehicle weight, intended driving style, driver skill, etc? Does a generally lighter weight setup make for a more precise, but maybe harder to drive, setup?
My track is hard pack, bumpy , generally dry and dusty, unless i sweep and water it. And being new to this, my driving skill is not super consistent. Although getting better!

 

[nino]

I think you have to take into account the differences in load (power, tire size, weight), and design differences in the diffs themselves (volume, gear setup). On the trigger finger side, racers will tend to ease on the throttle and probably prefer a smoother setup, and use 2s or 4s (where 3s or 6s would be common for the same size basher vehicle). Bashers on the other hand probably won't mind wheelies and lack of finesse when cornering.

My SCT410.3 was set up as a basher before I got it and it had some mighty thick fluids and metal diff cups. I went to plastic and stock weight (7 7 5 IIRC). A world of difference! More responsive, feels more nimble and fluid, with the heavy oil it just didn't steer well and going through corners you never knew what it's gonna do.

 

[bill_delong]

I don't have any experience with the Pro4 but my SCT410.3 would go anywhere between 15-15-7 to 10-7-3 and just about anything in between that range with the following adjustments in mind where you need to figure out what your preference is for your given "tuning window":

 

[Lumikko]

So far with my testing on my track i think i prefer something around 30/30/10 to 20/30/5. But still experimenting.
It just seems when reading through various setup guides that in the off-road buggy/truggy world the diff weights used in racing are much much lighter than what is called for in the manual. I.E. 5/7/3 or 7/10/5 etc.
Is this a product of vehicle weight, intended driving style, driver skill, etc? Does a generally lighter weight setup make for a more precise, but maybe harder to drive, setup?

Vehicle weight and tire diameter certainly affect suitable diff oil weights. Also, it’s possible that different gear modules require specific weights to achieve the desired resistance – much like shock piston diameters and hole sizes+counts.

As a very coarse and general rule, more open diffs should be easier to handle; a heavy trigger finger spins one tire rather than the whole axle. I don’t quite understand why the stock setup is so heavy especially in the front. Maybe the Pro4 handles funny because of the pro-squat geometry and hard rear springs. The stock diff oil setup could compensate for this.

For reference, the kit setup for the B74.2D is 10/200/10 so at least the center 100k of the Pro4 doesn’t seem particularly heavy. After all, not all vehicles even have a center diff.

 

[RustyUs]

Vehicle weight and tire diameter certainly affect suitable diff oil weights. Also, it’s possible that different gear modules require specific weights to achieve the desired resistance – much like shock piston diameters and hole sizes+counts.

As a very coarse and general rule, more open diffs should be easier to handle; a heavy trigger finger spins one tire rather than the whole axle. I don’t quite understand why the stock setup is so heavy especially in the front. Maybe the Pro4 handles funny because of the pro-squat geometry and hard rear springs. The stock diff oil setup could compensate for this.

For reference, the kit setup for the B74.2D is 10/200/10 so at least the center 100k of the Pro4 doesn’t seem particularly heavy. After all, not all vehicles even have a center diff.

For anyone running their sct’s on outdoor dirt/clay tracks, what are you running for diff oil weights F/C/R?
The manual for my AE pro4 sc10 calls for 60/100/3, which seems really thick in the front and center compared to any of the stuff I've read on the internet.
I've ran all sorts of weights, but have not settled on anything.

When the Pro4 SC10/Rival MT10 came out, I thought the same thing. I thought for sure there was a misprint in the Pro4 SC10 manual or something. I could see the MT10 using 60/100/3k more so than the Pro4. I could not find any reference to any oil/fluid thicknesses, to compare, what was used on the Helion Avenge platforms... those manuals were very lacking.

 

[RustyUs]

I agree, and baffled at the same time with Associated's printed Pro4 SC10 "out of the box" stock fluids usage. My take on the whole Pro4 SC10 thing is, Associated never intended the platform to enter a higher level of competition/major events. Sure, you can race any platform, but a RC platform that starts out as a rebranded design; RTR; LED lights; no kit option, and no setup sheets... not the way Associated typically goes about their "racing breed" platforms. I was, and still am (just not as huge), a fan of Team Associated. I guess I'm just used to the way of years past.

 

[RustyUs]

I don't race, per se, anymore, but still test/tune my RCs to run great on rough backyard track. My SCT410.3 has 7/7/5k (front/mid/rear) in it and the SCT410SL has 15/20/7k for running on tight medium/loose dirt track. I will note that the SCT410SL stock setup, in manual, was 30/30/20k... intended for higher traction surfaces.

 

[islandlife]

I don't race, per se, anymore, but still test/tune my RCs to run great on rough backyard track. My SCT410.3 has 7/7/5k (front/mid/rear) in it and the SCT410SL has 15/20/7k for running on tight medium/loose dirt track. I will note that the SCT410SL stock setup, in manual, was 30/30/20k... intended for higher traction surfaces.

Also dont race, but love the testing/tuning aspect of rc (or anything for that matter).

 

[Lumikko]

The Pro4 and MT10 have a raised ”belly” of the chassis as to not get it stuck on obstacles. It raises the CoG quite a bit and really lowers the corner speeds you can achieve. Obviously not a design choice made with racing in mind.

It could be that the thick diff fluids aim at the same goal: not getting stuck all the time when the truck is being driven here and there outside of tracks. Race cars get stuck stupid easy because the diffs are loose and open, bashers dislike that a lot.

When tuning guides advise to start with the kit setup, it is presumed that the kit setup was intended for racing on a track. This may not be the case with the Pro4.

 

[islandlife]

The Pro4 and MT10 have a raised ”belly” of the chassis as to not get it stuck on obstacles. It raises the CoG quite a bit and really lowers the corner speeds you can achieve. Obviously not a design choice made with racing in mind.

It could be that the thick diff fluids aim at the same goal: not getting stuck all the time when the truck is being driven here and there outside of tracks. Race cars get stuck stupid easy because the diffs are loose and open, bashers dislike that a lot.

When tuning guides advise to start with the kit setup, it is presumed that the kit setup was intended for racing on a track. This may not be the case with the Pro4.

Seems reasonable.