Failed CV Joint = No AWD?!
12-02-2007, 03:48 PM
#11
Well, no, but kinda.. You will lose some go if you are on bare ice, but even that ....
has enough resistance to send power to the other end.. It's mainly if there is fully 0 resistance on either end when you get this situation. I've always wondered what would happen if you just jammed the dead axle up against something, if it would cause the power to shift across the diff and drive the car...
12-02-2007, 06:00 PM
#12
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re: quattro
I was under the impression that quattro would send power to the non-slipping wheels. The ABS sensors detect wheel spin and thus adjust the electronic diff's to send power to the non slipping wheels.
BUT... in this case, yeah, the wheel isn't moving at all (ABS sensor sees no trouble).
The front diff isn't torsen, it's electronic locking, according to Wiki.
BUT... in this case, yeah, the wheel isn't moving at all (ABS sensor sees no trouble).
The front diff isn't torsen, it's electronic locking, according to Wiki.
12-03-2007, 04:20 AM
#13
no, that's incorrect. There are no electronic diffs. They are fully mechanical, non-locking diffs.
With ANY differential of this nature (including Torsen), the power will go to the side with the least resistance. So if you have an axle with NO resistance, the power will naturally go to that side. If you lock that axle completely, the power should work it's way out the side that can turn.
Just so you are clear, the EDL on the recent quattro system uses the ABS to pulsate the brakes individually to create resistance on wheels that are spinning, which causes the differential to send power to the opposite side. This works about as well as you'd expect it to however (in other words, not very well).
Having said that, I've been stuck with an Audi with quattro exactly three times. All 3 times were because I had beached the car on top of a large pile of snow. one time I was able to dig the snow out from under, the other 2, I had to pull it off with my tractor. These were situations were NO wheels were on solid ground. =)
Just so you are clear, the EDL on the recent quattro system uses the ABS to pulsate the brakes individually to create resistance on wheels that are spinning, which causes the differential to send power to the opposite side. This works about as well as you'd expect it to however (in other words, not very well).
Having said that, I've been stuck with an Audi with quattro exactly three times. All 3 times were because I had beached the car on top of a large pile of snow. one time I was able to dig the snow out from under, the other 2, I had to pull it off with my tractor. These were situations were NO wheels were on solid ground. =)
12-03-2007, 09:13 AM
#14
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Just so I'm clear...
Once again... if you have one wheel that slips 100%, quattro will not motivate the other 3 wheels to move the car?
Granted, you're probably going to have at least a tiny bit of traction (and thus that's multiplied by the Torsen to the other wheel?)...
And this doesn't apply to the B5?
<a href="http://en.wikipedia.org/wiki/Quattro_%28all_wheel_drive_system%29#quattro_gener ation_IV">Link</a>
"Torsen effect with one wheel in the air will not happen on quattro IV because Electronic Differential Lock will apply brakes to spinning wheel and Torsen differential will transfer torque to rear axle."
Now, in the case of a CV boot broken, the car doesn't know the wheel is spinning.
Granted, you're probably going to have at least a tiny bit of traction (and thus that's multiplied by the Torsen to the other wheel?)...
And this doesn't apply to the B5?
<a href="http://en.wikipedia.org/wiki/Quattro_%28all_wheel_drive_system%29#quattro_gener ation_IV">Link</a>
"Torsen effect with one wheel in the air will not happen on quattro IV because Electronic Differential Lock will apply brakes to spinning wheel and Torsen differential will transfer torque to rear axle."
Now, in the case of a CV boot broken, the car doesn't know the wheel is spinning.
12-03-2007, 11:57 AM
#16
It would, but since it's a differential, the output of the non-jammed one will spin twice as fast as
it's should, and the rear diff with equal output will spin at normal speeds. Can compensate with one really small front tire I guess 