Torque Splitter on XC vehicles

[J3cubfan]

I got my MU the other day and can't wait to build it. Of course there are some other projects that are ahead of it in the queue. My question is this. I've noticed that there is some hop up option called a torque splitter. I am not what it is that this thing does outside of shifting the power from one wheel to another. Does anyone have this on their XC (Pajero, Wrangler, MU) rides, if so is this thing really effective? How does this work?

thanks again.

John

[Bibbo]

Hi J3,

I have a Pajero MT. I have actually just fitted a torque splitter to it. It also has full bearings and the sport tuned motor. I hav'nt actually driven it with the splitter in yet but basically it allows the front wheels to turn freely in one direction but be driven buy the motor when they are not free wheeling. It's difficult to explain really. It basically has a one way bearing inside it, which is a bearing that turns one way but locks when you turn it the other way.

I am realising how difficult this is to explain now!![][] But it has nothing to do with the independence of the front wheels from each other, it splits the torque from front to rear so that if the front wheels need to go faster than the rears they can.

I have heard that it does'nt make much difference to the driving though.

[Shodog]

Essentially it is a one way bearing for the front wheels. This is helpful if you drive on pavement a lot. One of the reasons I haven't done this upgrade is because your front wheels will have no braking power and when you reverse, only your rear wheels will work. Really only one wheel if you have not locked your rear diff.

Jim

[bholio]

The torque splitter is meant for cars which are run on dry pavement. Whenever you turn, the front wheels spin at a different speed than the rear wheels. So, either the car stops or something has to give when turning. In most cases, a tire slips.

A slipping tire is no longer gripping the road, so you lose traction/handling in turns. In addition, the drivetrain of the car takes additional stress before the tire starts slipping. That 1-way bearing allows the front wheels to spin at a different speed than the rears so this doesn't happen. I have no idea if this makes a noticable difference in a toy car.

In a real (1:1) 4WD drive car, driving it in 4WD causes increased tire wear and possible breakage of expensive parts of the car. That's the reason for full-time 4WD or all-wheel drive systems. You should never drive a standard 4WD truck (in 4WD) on dry pavement (or even rain IMHO).

You MU does have a hop-up in the box on the G-parts tree. There is a piece in there which you can use to lock the rear differential. This will make a noticable difference in your car. It will force both rear tires to spin at the same speed, all the time. This is very useful in low-traction/rock climbing situations. No more getting stuck because 1 rear tire is in the air.

If you are going to drive off-road, low-traction, try the g-parts thing and do not use the splitter. If you plan to drive mostly on pavement, use the splitter and do not use the G-parts thing.

[J3cubfan]

This is the "MU on-road" and thats probably where I end up driving it. Thanks again for the information guys, I sure do appreciate it.[] What I am most curious is how this thing will act on slippery surfaces such as ice and litely snow covered asphalt roads ie parking lots. I will probably invest in a torque splitter after the first of the year.

John

[Bibbo]

Heah Jon,

I have the locked diff in the back of mine. I have driven it a lot with this as I was using it mainly off road. It is really good with it in.

You say you want to try it on light snow and ice. I did this last year with mine in the park over the road. On the pavement in the ice you can do awesome rear drifts with the locked diff. You can really hold it out sideways and make long tracks in the ice/snow and watch it spray up all over the place.[][][][] Without the diff lock in it just spins away the power as you would expect and goes in a straight line.

The other guys explained the torque splitter much better than I ever could!![V]

[J3cubfan]

You guys mention something called a "lock-out" option on the XC vehicles. Is this a switch that you can "switch" over during operations or is it a option during assembly?

John

[Bibbo]

No, the locked diff is in the back. You use some option parts in the kit that you insert in the rear diff to lock it.

You have to take the rear diff ( axle ) apart to change between locked/unlocked

[J3cubfan]

Ahhh I see.[8)] Ok, I'll try the lock option on the car once, if ever comes time for assembling this thing. I can't wait but have to finish a couple of other projects first.[]

[stulec52]

I got my CR-V to build in the next month or so, and thanks to all for contributing all those handy tips. As Calgary seems to have snow all the time, I see a locked diff in my near future, although I'm worried that locking the diff, and the CR-V's slightly longer wheelbase will mean terrible turning?? any ideas, opinions?

[Bibbo]

quote:

Originally posted by stulec52

I got my CR-V to build in the next month or so, and thanks to all for contributing all those handy tips. As Calgary seems to have snow all the time, I see a locked diff in my near future, although I'm worried that locking the diff, and the CR-V's slightly longer wheelbase will mean terrible turning?? any ideas, opinions?

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At the end of the day the locked diff is, like most things in life!!, a compromise. []

[WillyChang]

quote:

Originally posted by stulec52

...although I'm worried that locking the diff, and the CR-V's slightly longer wheelbase will mean terrible turning?? any ideas, opinions?

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Stu:- on a racecar, a locked rear diff (or very tight balldiff) usually makes less grip in the back, so this should *increase* steering.

Given that the XC has a solid live rear axle, its unlikely unless you're rockclimbing that the rear will hike any wheel enough to lose all rear drive. The weight is well balanced on both rear wheels.

Re: "torque splitter", its just a fancy name for a one-way bearing on the front layshaft (bit like the TA03's). Bought one long ago, but its still sitting in the pack; I don't see the point of it as your XC wheels are going to be all the same size front & rear, so there's not going to be any rotational differences.

Yes - when steering around a corner, the inner wheel tracks a shorter path than the outer wheel. But this is what the 2 diffs are for.

[J3cubfan]

Hi Willy:

thanks for the insight. so you think that the torque splitter is not worth the investment? After reading your post, it makes sense that the inner wheel would track shorter versus the outside wheel during a turn. That's where your differential would come into play.

thanks again for the tip.

John

[WillyChang]

quote:

Originally posted by J3cubfan

Hi Willy:

thanks for the insight. so you think that the torque splitter is not worth the investment? After reading your post, it makes sense that the inner wheel would track shorter versus the outside wheel during a turn. That's where your differential would come into play.

thanks again for the tip.

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John:- uncertain about your own mentality, but personally for a tiny item like that I'd usually just "buy it first, worry about it later". I know from experience that when I actually get around to thinking of using it, it'll never be in the same shop again. [] Grab it first and its one less "what if" regret to moan about to the greatgrandkids. []

[DJTheo]

quote:I don't see the point of it as your XC wheels are going to be all the same size front & rear, so there's not going to be any rotational differences.

Yes - when steering around a corner, the inner wheel tracks a shorter path than the outer wheel. But this is what the 2 diffs are for.

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Thats not correct, also the front wheels drive around larger radiuses then the respective rears, except if the car has all wheel steering with the same (opposite signs) steering angles. Thats why all rear 4WD trucks have a 3rd diff and if not 4WD should be switched on only at slippery surfaces. But RC cars transmition parts are relatively overdimensioned, so they can stand also driving with only 2 diffs, but in the end you always have slip on the tires.

[stulec52]

quote: on a racecar, a locked rear diff (or very tight balldiff) usually makes less grip in the back, so this should *increase* steering.

id="quote">id="quote">

Willy, not true to my way of thinking........ on a medium to high grip surface, a locked diff means that the inside rear wheel pushes the car through the corner... I mean anyone ever driven a standard Rough Rider, Sand Scorcher etc ? then fit a diff, the amount of turn in you gain, again on medium to high grip surfaces, is amazing.

Certainly though if the grip level is low, you can slide both rear wheels to get around corners quite well.

I suppose at the end of the day, it comes down to personal preference, and driving style, and also the surfaces you intend driving on.

I'll let you all know how I get on with my CR-V, I will be trying a few different setups.

[Bibbo]

At the end of the day there are Torque splitters on e-bay with a BIN of $10 plus $5 shipping. I say "buy one and give her a go!"

How far wrong can you go for $15

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...item=1920467674

[WillyChang]

quote:

Originally posted by stulec52

...on a medium to high grip surface, a locked diff means that the inside rear wheel pushes the car through the corner...

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Yes that's true... but the wheel will also be fighting the other wheel on the axle at the same time; there's only a finite amt of grip available so imho both will lose some drive grip each.

There is also high chance that the car will be leaning to the outside of the turn... thus the outside wheel will have more weight bearing on it, thus lesser propensity to slip. This tyre might well be the one driving the car through the corners.

A locked diff's biggest benefit is to avoid "loading up" of the inner wheel, where all drive torque goes wasted to spinning a gripless wheel. At least now the driving wheel (outside?) always turns the same speed as the inner wheel.

[stulec52]

which is surely why a limited slip diff has to be the best answer?

I don't suppose there is such a thing for these cars??

[WillyChang]

We could pack the diffs with thick grease... []

[DJTheo]

I remember there existed an RC car with a torsen diff. A torsen diff, works like a normal diff allowing different rotational speeds, but transmits the higher torque to the tire which has the highest resistance i.e. grip and therefore is the best solution, much better than locked or limited slip diffs... Also some good real cars have one...

[jerzirccar]

HI!

I had one way bearring in my 1/8 scale buggy(t2m) and it was superb to drive but the problem was that the rear diff broke very easly so I had to remove it. In the TT Predator 1/10 buggy there is no one way bearring (in the first model) so I tryed on the carpent to drive with it but no way it was terrible to drive when it has this 4 wd all the times on.

Jerry[]