johnner1999

an odd thing happend to me and my 100csq last night. coming up my steep off camber driveway - one of the back wheels became off the ground and both front wheels should be on firm land. and the rear wheel spun as it should - but the car started to stop moving... shouldn't the torsen system send power to the front during this example? I locked the rear diff and the car went stright up :-)

CK:1.8T+Rabbitâ„¢

Posted once that if one entire side of the car loses traction, the torsen disengages. I don't know if I buy that. I know once I got stuck in deep snow (being stupid and driving into snow too deep) and only the LF wheel was spinning. I tried ot lock the diff, but the front wheel would spin up very fast and the diff would unlock.

johnner1999

same thing happens to my wife's Montero Sport that has full time AWD but that system is pretty crappy compared to the torsen system (I think?) and you can lock the center diff on hers and it normally goes UP fine.

I had a awd civic wgaon for a few months before buying the 100 and it used some strange oil clutch packs - but was very good???


Maybe one of the fronts was also having traction issues???

Edd W

in the torsen diff.

If a wheel has no traction at all, as in, it is the air, then all the drive can go to that wheel. I have seen this also and I think it is because for the worm gears to force the torque to the place where there is traction, there has to be some resistance in both direction, ie front and rear. If one output from the diff has no resistance at all, this, it seems, can happen.

If this were not the case, why do Audi now fit EDL on later cars. If the torsen diff were perfect in all conditions, then it would never be necessary would it?

EDL will provide 6the resistance that the system needs to force the torque to the wheels where there is grip.

I think from the way the diff is designed, this situation will only occur when the car is stationary. If the wheels are turning a small amount and one or two start to slip, then it works as it is supposed to.

It comes down to the way it is actually designed to control the speed difference between its outputs (speed is created by torque so you could read torque, but speed is easier to understand).

If the fron wheels are stationary but one or both of the rear wheels are able to spin freely then the differemce between the two outputs is infinite. If whowever the front are turning at 10 rpm and the rear at 50 rpm then the difference is within the designed limts for the diff to cope with.

The situation you had created a difference that is outside those limts hence - no traction and a spinning wheel in the air.

I know this goes against what we are told in all the marketing blurb, but this is what actually happens in the real world.

I may be wrong in my theory and I would welcome a better minded insight into what is actually happening in this situation, if anyone has better ideas? - The whole point of this forum is to learn.

greenaudi100

You probably gave to much gas and once the tires spun past ~15mph, the diff goes back to normal

CK:1.8T+Rabbitâ„¢

Was still spinning at about 10-15 MPH.

johnner1999

thanks for your info - i think you hit the nail on the head.

it is most likly a "safty" thing for the worm drive?

CalG

The Torsen diff splits the power front to rear ONLY (Unless you have an older V8).

The Left to right split is "controled" by the EDL
Which is just an adaptation of the anti lock brake system.
Other wise it's just an open diff.

I hope this clears up some details

regards

Calg

snowman '92 100

<a href="http://www.tomservo.cc/ct.ashx?id=04a1241e-1403-41f4-9354-8c79e955b62c&url=http%3a%2f%2fpatrick.fm%2fvideo%2 fwww.kicken.com-snowtowcar.wmv">clicky clicky</a>

snowman '92 100

If the engine is on, there's gas...If it's an AT, then there's still power going to the wheels.