Talion Center diff oil weight increase causing spinouts?

[jjl5590]

Hi,

I increased the center diff oil weight to 1M in preparation of some speedruns. I didn't want to lock the diff with a spool so this was the next best option.

Using some brand new road crusher tires, it wouldn't stay in a straight line. It was like driving on ice. Is too much power going to the rear wheels, just causing it to spin out? Ironically I still wasn't able to wheelie.

I haven't tried the 1M oil with the stock tires, so it could be the road crushers...

What is the stock center diff oil weight? Would 500k or 100k be more appropriate?


Many thanks

 

[BashNerd]

Stock for the Talion is 100k in the center.
I am running 500k and I am very happy with it. There are a few also running 2M in their center diff.

 

[Ari33]

Yes, anything above the stocks 100k increases drive to the rear wheels. Acceleration will be much improved but if your tyre compounds are a bit on the hard side and you are spinning out you can choose between (or a combination off)... softer rubber, a lighter centre diff oil, lower punch setting or better throttle control.

I prefer having to learn better throttle control but we are all different.

 

[jjl5590]

Yes, anything above the stocks 100k increases drive to the rear wheels. Acceleration will be much improved but if your tyre compounds are a bit on the hard side and you are spinning out you can choose between (or a combination off)... softer rubber, a lighter centre diff oil, lower punch setting or better throttle control.

I prefer having to learn better throttle control but we are all different.

Thanks for the advice, I've got punch reduced and have a light throttle finger - even so it would spin out past half throttle.

Can't change the tyre compound as they are SRC belted tyres, one of the only ones good for speedruns.

Are you saying stock oil weight is 100k? Maybe I'll try 500k then.

 

[Ari33]

Are you saying stock oil weight is 100k? Maybe I'll try 500k then.

Yes stock is 100k, going to 500k will certainly help. You can always go up a bit again in the future till you find the sweet spot... if required.

 

[slick2500]

Thanks for the advice, I've got punch reduced and have a light throttle finger - even so it would spin out past half throttle.

Can't change the tyre compound as they are SRC belted tyres, one of the only ones good for speedruns.

Are you saying stock oil weight is 100k? Maybe I'll try 500k then.

I hate to say it but Roadcrushers are not the only good tires for speed runs not one of the top speed run guys run them if that says anything.

 

[Bashaddict]

Hi,

I increased the center diff oil weight to 1M in preparation of some speedruns. I didn't want to lock the diff with a spool so this was the next best option.

Using some brand new road crusher tires, it wouldn't stay in a straight line. It was like driving on ice. Is too much power going to the rear wheels, just causing it to spin out? Ironically I still wasn't able to wheelie.

I haven't tried the 1M oil with the stock tires, so it could be the road crushers...

What is the stock center diff oil weight? Would 500k or 100k be more appropriate?


Many thanks

maybe your barking up the wrong tree?, I've been there don't that many times my friend ! .....how's your alignment, specifically the front needs to be toed out.

 

[jondilly1974]

Never heard of roadcrushers being used for speed runs. GRPs and BSR foams.

 

[SrC]

200k, then 500k. But wheel alignment and tires are very big factors in the equation. Don't overshoot your center diff weight. And what are your F and R diff fluids at now along with the 1M center?
But 1M is just basically locked or approaching very close to it depending on ambient temps. Going up that high on the center may also require trimming your F and R diffs a bit. One change at a time. IMO. Obviously 1M changed your handling for the worse, and changes have to be made somewhere. Toe out can help. ST rate or expo adjust. Don't overlook your shock tuning also. Droop etc. It just may be only the tires.
Just some ideas....

 

[BLXLyfe]

pickup the dumborc radio, has built in gyro and will help alot. radio is super cheap too.

 

[SrC]

A gyro setup of some type will only help, but up to a point. Successful speed runs upwards of 80+MPH will almost always require a ST. gyro of some type.
The above OP issue requires more than a band-aid approach however. A gyro will not compensate for any poorly set up rig. It will only complicate matters. IMO.

 

[BLXLyfe]

correct tires/tyres/gyro will aid greatly, you need to specifiy what you mean by poor setup...

 

[SrC]

Poorly set up could mean any and all that I stated above. I run two AVC srs6000's. One on road and also an off road. Gyro aside, a bad setup is a bad setup. I prefer to dial in my rig with gyro disabled first, especially when making major changes.

 

[LibertyMKiii]

maybe your barking up the wrong tree?, I've been there don't that many times my friend ! .....how's your alignment, specifically the front needs to be toed out.

Sorry, I don't like to correct people (feelings can get hurt)
This is not correct.

You want straight or slightly toe in. Toe out will cause the car to grab grooves in the road and dart around. It will have an overall un-controllable feel.
(This is no different than road cars/SCCA or track day alignments. )

I cannot imagine the center diff being locked as the issue. Most of us run solid spools and have no issues like that. I would say alignment, learning smooth throttle application, and most importantly the tires. GRP S3 compound is the best option IMO. You could also order some dBoots Hoons as an alternative option.

-Liberty

 

[SrC]

Toe is absolutely never negative . Period. Not for straight line speed, for sure. Zero+/-.5 degree toe is acceptable tolerance. More Toe out benefits on technical tracks or driving style. Yields more turn in, less push or understeer. Excessive toe in at speed causes unpredictable steering. Toe out at speed at a certain value can create somemore stability. But at speed zero toe avoids tire scrub and its undue wear. I don't pretend to know about wheel aligning. I do know. I've worked on scale cars using some of the best $120k Hunter alignment racks around.

 

[BLXLyfe]

Poorly set up could mean any and all that I stated above. I run two AVC srs6000's. One on road and also an off road. Gyro aside, a bad setup is a bad setup. I prefer to dial in my rig with gyro disabled first, especially when making major changes.

i think the spektrum is your problem from the start haha

 

[LibertyMKiii]

Toe is absolutely never negative . Period.

To clarify (because it sounds backwards for example negative camber is where the tire leans in)
Negative toe is where the front tires would point slightly out.

Great explanation:

"Negative toe increases a cars cornering ability. When the vehicle begins to turn inward towards a corner, the inner wheel will be angled more aggressively. Since its turning radius is smaller than the outer wheel due to the angle, it will pull the car in that direction.

Negative toe decreases straight line stability as a result. Any slight change in direction will cause the car to hint towards one direction or the other. "

-Liberty

 

[SrC]

The OP is trying to setup a speed run rig. Maybe he over weighted the center diff. Yet there are ways to compensate for that 1m drastic change. Maybe traction issues. There are many other factors. But Toe-in and the immediate need for a gyro is not the answer. SORRY, not in my opinion,

i think the spektrum is your problem from the start haha

I don't have any problems. But I could change that real quick if you prefer.
Basic stuff.

 

[LibertyMKiii]

Phillip Jolley who is undoubtedly the king of speed (many runs over 150mph) told me he does not use a Gyro and never liked them.

-Liberty

 

[jjl5590]

Thanks for all the replies.

Yeah I'm aware of the GRPs but they're so small and look stupid on a Talion lol.

F/R diff weight is 50k/30k.
I've gone down to 500k in the centre but not tried it yet.

Its probably to do with my setup. I do have a steering gyro which is built-in to my Radiolink rx, but I don't know how to set it up. When I activate it, the wheels just wobble and becomes very unstable.

It could also be to do with the face that I'm running an SSS 4092 & Max6, even though I've got a 22T pinion on there it's still pretty powerful. Temps never get above 45C though...