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Video: Subaru v Volvo


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sebberry, that's what i tried to write yes, and i think AWD_rules just missinterpreted :)

 

Volvo replaced the VC for Haldex clutch based coupling, but they still don't have any center diff....

 

Volvo is very expensive when you look at the AWD models (XC70,XC90) and you only get a crappy Haldex with no diff's.

Audi A3/TT use the same with Haldex coupling and no diff. The other quattro use torsen diff, wich is one type of TBD=Torque Biased Differential. Subaru LSD is another type of TBD. Same same, but different :)

 

My Subaru use the LSD center diff, but what kind of diff is there in front? And what kind rear?

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haldex-like systems can lock without slip based on newer pump/electric systems, not just passive anymore. Basically think of them like the electronic locker on the STI set on automatic, minus the center diff and the ability to manually adjust locking percentage.

 

For example, WOT will fully lock the clutches before wheelspin occurs.

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I dunno, does this look like the Suzuki forum? :lol::wub:

 

Haha admit it, we dont know what did they use under their car.

 

 

Well we're already discussing Audi, Volvo and Subaru AWD systems so why not Suzuki as well? :)

 

Yeah, thats why i didnt start a whole thread just on suzuki AWD. Might as well keep it altogether.

But you know, their SX4 seems pretty decent.

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Hmm.. ok.. does it have VTD? If so the center is probably a planetary diff with a hydraulicly operated multiplate clutch pack.

 

With VDC the front and rear are open differentials as the VDC system limits slip by applying the brakes at the slipping wheel. Similar net effect as having an LSD in the rear. Only the 2007 SpecB uses a torsen at the back with VDC. .. god only knows why they used a Torsen.. ah.. brand recognition...

 

 

Hmm.. how do i know if i have VTD? I thought all VDC cars had VTD, but i don't know. And maby the Japan cars are different from US-cars?

 

And how do i know if i have open diff front/rear or some LSD diff?

 

The car certainly seem to transfer torque from side to side when i put it in difficult conditions with ice+snow...

 

Can it be that bad that they don't use LSD center differentials on VDC cars? No, on the websites they say alla subaru have LSD center diff....

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sebberry, okay then i guess i'm happy with the VDC :)

So far it works like a charm. If breaking is applied to the spinning wheel, how much torque is transfered to the other wheel? 100% according to the commercial, but is that true? One wheel in the air and the other on tarmac.

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Max amount that the brake can apply to the wheel in th air will be available to the wheel on the tarmac. So say 80lbs-ft to move the braked wheel in the air, 80lbs-ft to the wheel on the tarmac. Open diff always wants to be equal.

 

Couple of reasons why it isn't good for an off-roader. Brakes can overheat, and you are only seeing 50% of the rear axle torque going to the wheel with traction versus the near 100% with a locker system. Combined with torsen it can be effective, since the amount of torque to the wheel on the ground is 3-5 times more than the brakes wheel in the air. Believe this is the system the Hummer used for a while.

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no. it defaults to it's standard torque bias, and doesn't "vary" from there. I think.

 

You can't turn off a differential. it is installed, so it is working. If it weren't working, really, your car wouldn't move, the transmission would just spin.

 

It just that the computer controlled variance gets disabled, and the standard 55/45 torque split takes effect, and doesn't vary from there. Mostly like the MT 50/50 system, just 5% more rear bias.

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no. it defaults to it's standard torque bias, and doesn't "vary" from there. I think.

 

You can't turn off a differential. it is installed, so it is working. If it weren't working, really, your car wouldn't move, the transmission would just spin.

 

It just that the computer controlled variance gets disabled, and the standard 55/45 torque split takes effect, and doesn't vary from there. Mostly like the MT 50/50 system, just 5% more rear bias.

 

 

Okay nice. But i get 60% front and 40% rear as default torque split. I have the 4EAT automatic. The 5EAT get 45%-55%. At least according to Subaru Sweden.

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