LSD Torque quite weak

It is said that even clutch pack diff allows you to drive off from car jack if you jack one side wheel off the ground.

D15 has 150Nm preload at rear diff, while wheel torque powertrain delivers 8000Nm or so in Low range.

In practice there is hardly any difference between open diff or LSD in situation where you get two wheels off the ground and you have LSD at front and rear axle.

Then there is multiplier of 0.2 for LSD which provides cross torque, but when one wheel is up in the air, cross torque does not apply, right?

I have not found out how much IRL such clutch pack preload is, but I would think it is greater, because even clutch pack makes quite big difference in such situations to open diff IRL.

So I wonder if there is something that is off, is 150Nm thought to be from engine torque and in practice it is from wheel torque for example?

Then there is a spool type which I don't quite know how to make, because when one wheel is up in the air there is no locking action at all, while there should be with spool as it always locks when engine torque is put to it, at least based on what I read.

By setting preload to 500Nm I'm getting better results, it still allows wheel speed difference, so I think there is something that could be improved for vanilla LSD to be more useful as currently for offroad use I find LSD option pretty pointless in D15, it is same way stuck as with open diff when two wheels are off the ground.

 

Having had a truck with a stock clutch type LSD, It's enough to spin both tires on level ground but, you really need an upgraded differential if you're going to be doing real off-roading. It could get you through most articulation obstacles as long as both wheels were on the ground still.

Spools are equal to the welded differential in game. It's a locker you can't turn off. I guess technically, you couldn't even call it a differential because, it doesn't allow any difference in speed between the two axles.

 

I did read from some offroad board how LSD was much better, maybe after market clutch type can be then better?

With spool it is supposed to be open when not on throttle, so you can trick it to turn better, while welded is constantly solid.
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Ok, I found value of 190Nm for light cars that use 75 pound preload springs (this though is customization for autocross use), while trucks use 400 pound preload spring with 800 pound being upgrade, maybe, as usual information is avoided and people then to go by with "number 5 works" like with some religion, instead of sharing facts of what actually is actual effect, which is really frustrating when trying to do some research.

They did mention breakaway torque, which I guess is term for point which clutch starts to slip.
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I like how this explains things, but if clutch pack gives 190Nm breakaway torque, then with 3:1 bias grippy side tire should have 570Nm of torque even when slippy side would be on air as clutch pack is kind like brake for non grippy side?:
http://www.fourwheeler.com/how-to/t...-1007-living-with-limited-slip-differentials/

I think old Torsen discussion we had some table kind for bias to lsdLockCoef ratio, need to check that.

Perhaps I just need to make aftermarket LSD to get improvement on this, it is just finding few more numbers
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For anyone interested:
https://www.beamng.com/threads/torsen-differential.52065/#post-789776

Hmm, 0.2 would then be even on high side, 0.15 or something being OEM class by article, still not sure about preload which might be something would be then higher instead? There is so little data about OEM breakaway torque.
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A-ha, found numbers:

http://www.xterraownersclub.com/forums/ubbthreads.php?ubb=showflat&Number=49851

Supposedly numbers are from factory manual, so might be reliable?

Those vehicles are kind like Roamer but lighter?

Haven't seen data from C/K, would be interesting, but some Nissan models seem to have quite bit higher preload.

Also I presume preload is static and slipping is automatically determined.
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So after some number punching I had Nissan LSD kind made up, so I went to test out Open, Vanilla LSD and Nissan LSD:


I did put two wheels on ice, had camper trailer secured on place with node grabber and tested each of three trucks towing capability.
Open diff got around 9000N
Vanilla LSD got around 16000N
Nissan LSD got around 15000N

Next up was test where two opposite corner tires ar at air and you try to climb steep incline.

Open diff is not really good at this:


Nissan LSD did climb until it fell over:


Result was similar with Vanilla LSD, maybe bit weaker get to move, but after nudging to move it kept going until falling off:


Next up was getting stuck on rocks, where Open LSD did get stuck quite easily:


LSD models cope better, but while Nissan LSD is better at situations where two wheels are airborne, Vanilla LSD is better at situations where there is at least a bit of traction on all tires, neither could not make the climb, but Nissan LSD did cope slightly better in this test:


I did use lsdPreload":216 and lsdLockCoef":0.15 for Nissan type, which was between two extremes of one model listed.