Is the Quattro Torsen system better than the V70 AWD viscous system and why?
03-03-2002, 07:34 AM
#2
I remember seeing a road-test video...
conducted by a Swedish automotive magazine comparing the Volvo XC to a Subaru Outback. The test was to drive up a slippery, muddy road. The Outback performed well in these conditions, while the XC simply could not get up the hill after numerous attempts. Apparently, the XC was sticking in FWD only, and not recognizing when AWD needed to be activated, resulting in spinning, smoking tires. Doesn't the Volvo XC use a version of the Haldex system? I've heard other reports of spotty AWD perfomance from the XC, so I've shyed away from considering it.
I would have wished the Avant was included in the same test, but even so I hear the quattro has very capbable AWD with its Torsen system.
You might also want to check out the link to a description of various AWD systems.<ul><li><a href="http://home.attbi.com/~eliot_www/awd.html">Introduction to AWD Systems</a></li></ul>
I would have wished the Avant was included in the same test, but even so I hear the quattro has very capbable AWD with its Torsen system.
You might also want to check out the link to a description of various AWD systems.<ul><li><a href="http://home.attbi.com/~eliot_www/awd.html">Introduction to AWD Systems</a></li></ul>
03-03-2002, 08:08 AM
#3
The QTR system is always working, and does not have to wait for slippage to occur before working.
The viscous coupling requires some slip occur before the "dead" axle is activated. By then, it may be too late.<ul><li><a href="http://www.fortunecity.com/silverstone/lancia/58/technical_school/traction/tech_traction_4wd_2.htm">http://www.fortunecity.com/silverstone/lancia/58/technical_school/traction/tech_traction_4wd_2.htm</a</li></ul>
03-03-2002, 10:44 AM
#5
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Fact about the S60 AWD ...
It should be noted that in Volvo's new AWD S60, the AWD system is the same Haldex system as in the Audi TT. Although the system is dubbed Quattro in the TT, it's a very different system than the Torsen system in the other models (this was necessary since the TT uses a transversely mounted engine). So, it's interesting that Quattro itself can mean different things (although I think things are pretty clear in this forum, since it's an A4 forum after all!).
The Haldex system uses a multiplate wet clutch, in which slippage causes a pressure buildup which actuates the clutch. The control computer controls a pressure relief valve, allowing precise computer control over the nature of the engagement. Although it requires slippage to work, it's supposed to be very sensitive, engaging after only 15 degrees of wheel rotation. Still, a recent comparo between the A4 and the AWD S60 stated that the Haldex system is not transparent and seems to work best to get the car moving in bad conditions rather than assisting driving performance on the turns.
I'm just feeling chatty today. There's no other explanation why I decided to answer a question here that nobody even asked.
The Haldex system uses a multiplate wet clutch, in which slippage causes a pressure buildup which actuates the clutch. The control computer controls a pressure relief valve, allowing precise computer control over the nature of the engagement. Although it requires slippage to work, it's supposed to be very sensitive, engaging after only 15 degrees of wheel rotation. Still, a recent comparo between the A4 and the AWD S60 stated that the Haldex system is not transparent and seems to work best to get the car moving in bad conditions rather than assisting driving performance on the turns.
I'm just feeling chatty today. There's no other explanation why I decided to answer a question here that nobody even asked.
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03-03-2002, 01:56 PM
#8
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2001 XC locks out of awd above 40...wife has one...
My wife has a 2001 XC and I hate driving the thing. It has some pep but it feels like your driving a front wheel drive car (thats what it is) I was pretty pissed when I found out that it disengages above 40 (after I bought it-my own fault for not doing the research). I thought it was going to be similar to Quattro. I have heard they increased the mph lockout with the 2002's. When I am at a stop light the car disangages from 1st in nuetral. When you press the gas pedal it shifts into first (awful clunk). Dealer said that is normal for 2001. Whatever you do do not buy a Volvo. Get a Allroad. The only good thing I can say about the Volvo is the seats rock. I know this offers nothing technical about Audi vs. Volvo but from a person that has both-Audi rocks
03-03-2002, 05:11 PM
#9
one more thing...
cool article.
one of the other "expensive" vehicles that uses the Torsen system is... the AM General Hummer.
No joke.
Surprised this doesn't come up more often.
one of the other "expensive" vehicles that uses the Torsen system is... the AM General Hummer.
No joke.
Surprised this doesn't come up more often.
