Quattro not working as advertised - Anyone else experienced this?

It so happened that as I got to the restaurant of my choice yesterday the car park was full and so I decided I would make full use of Quattro to park by driving up onto a slope (about 12% steep) with only the two right wheels
onto a grass fringe (wet with hail from a recent storm) while keeping the two left wheels on the road's tarmac. I was pretty confident Quattro would have no problem in driving up along the fringe for about 4 m so that the car was out of anyone's way. Well, I was totally disappointed to get a bitter taste of the old days when we used to get stuck without Quattro. Still refusing to believe this, I got out to check that there was enough clearance all the way up and there certainly was. Then I made sure the car did not nosedive into the fringe. Everything was OK but the car still refused to start off uphill. My only resort was to shily reverse onto the tarmac and try to find a more traditional parking space.
I was taken aback in such a way that on coming out of the family reunion meal I asked both my father in his A6 2.5TDI Q and my brother-in-law in his 02 A4 1.8T Q (on winter tyres) to try the experiment, as they were telling me it must have been a case of my EDL not working properly. Well, they got the same identic result: the front right and rear right wheels kept spinning to no avail while the other two did not move an inch.
My conclusion is that while Torsen works flawlessly, EDL (Electronic Differential Lock) is no less than a big fiasco, at least when there is a big difference in terms of surface friction coeficient between the two sides of the car alongside.
I remember reading once that Jeep's Quadradrive and BMWs x systems had been the only ones to pass a certain traction test on rollers, while Quattro and the rest had failed, but I refused to believe this. Now I fail to understand why EDL does not work properly under those circumstances.
JP Roberts
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

park
snip
Umm, didn't you post this same message a few days ago?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

"If you don't like the answers, keep posting the question"
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Yeah, I read the exact same thing happened to you before too. And you're still surprised?
JP Roberts wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I thought it might skipped some people's attention, and these might have had some similar experience?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
JP Roberts wrote:

have had

If you must top-post, could you at least trim out some of the previous stuff?
Anyway, posting identical stuff a few days apart in a group that gets limited traffic will almost guarantee that the two posts will end up on the very same page of subject titles. But it is interesting that you posted using two different titles, and the bodies of the messages unchanged.
The bottom line? Everyone who cares read the first posting. Why don't you post it again in a month or three - you might pick up a couple of different readers.
HAND,
E.P.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The bottom line, which happens to be the top one here, is that since Quattro has always been the real appeal of buying an Audi, it should at least worry many more people than the ones who bothered to reply that it fails to work as advertised. I thought you American guys had some very strict laws about this.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
JP Roberts wrote:

Quattro
worry
work
about
And if you want to reach them, a limited-traffic newsgroup like this one isn't the answer. Take an ad out in a newspaper. Posting your sob story every week won't do anything.
Bottom-line: the folks who care have read your post. Please don't post the same story again. Post a link to it next time.
BTW, I have never seen any advertisements that claim that one side or the other of the car will get power if the other slips. Quattro is a front/rear thing, not a side/side thing.
My quattro has a vacuum-actuated diff lock engaged with an electric switch. Works great, and self-disengages on speeds above 10mph or on turns below a certain radius.
E.P.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Is that how it is on all quattros or just model years. The closest I have gotten to that situation is my 97 a6q. Hard acceleation with one side on gravel. It went go-go. No wheel spinning.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jules wrote:

I had always understood that quattro limits front/rear wheel speed differentials. Only the manually locking diffs would limit side/side wheel speed differentials. Whether through a vacuum system like my car, or a switch like the 4000/5000 series. (urQuattro too, right?)
E.P.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@gmail.com wrote: or a switch like the 4000/5000 series. (urQuattro too, right?)

Well I don't have a switch. But I have never been stuck, so I'm happy.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
This discussion reminds me of the commercial by GM? for an AWD SUV a while back, talking about how the vehicle senses the differing road conditions and adjusts the traction accordingly (has the inner voice of the driver thinking "dry....rain....snow....ice....") the ad ends when he rounds a corner, wide eyed, to see ball bearings on the road......... The quattro system is not a panacea for driving - there are many situations where different traction systems will be better than others (even RWD-only). As Wolfgang said, "I truly think quattro is not a substitue for an all terrain vehicle AWD with difflocks et all" My '87 5ktq would have climbed that hill, however, it also would have hopped like a bunny around subsequent corners if the diff locks did not have a chance to disengage (loads must be off the diffs), and you have no ABS when the locks are engaged (actually, I have no ABS, period, but that's another story). All of the revisions to quattro have been an attempt to somewhat "dumb it down" so that the driver does not need to see the upcoming ball bearings, reach down and switch on the difflocks. Jules had a more common safety-oriented situation - there was a fair difference in the torque resistance side-to-side and the car tracked straight. That's what's important. I'm sure that the quattro system on JP's car would produce lousy behavior as one of those stunt cars that drive on two wheels too. Cheers! Steve Sears 1987 Audi 5kTQ - hophophop - not only on Easter 1980 Audi 5k - fwd only 1962 and '64 Auto Union DKW Junior deLuxes - fwd only (SPAM Blocker NOTE: Remove SHOES to reply)

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

http://www.audi.com.tw/glossary/e/edl.htm
Quote: The electronic differential lock (EDL) permits smooth, comfortable starts on road surfaces that do not have a uniform coefficient of friction. If a wheel starts to spin, EDL brakes it as necessary so that power is transmitted to the wheel with the better traction. EDL reduces tire wear and works up to about. 40 km/h (quattro: up to about 80 km/h). EDL is part of the electronic stabilization program (ESP) and the traction control (ASR).
This is the advert. Notice the piece "If a wheel starts to spin, EDL brakes it AS NECESSARY so that power is transmitted to the wheel with THE BETTER TRACTION". This is totally false as in my scenario, the two wheels with the better traction where the ones that did even get any power at all, least of all the NECESSARY amount transferred from the brake actuation.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"JP Roberts"

Yeah, but they didn't say anything about "If two wheels start to spin..." like it was in your case. :)
Pete
PS: I know it sucks. The system isn't perfect. It's getting old and there are now more advanced AWD systems out there.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Pete wrote:

Actually IMO not in that class.
Regards
Wolfgang
--
1999 Audi A6 Avant TDI

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Notice this quote from Audiworld too:
http://www.audiworld.com/tech/wheel6.shtml
Electronic Differential Lock (EDL/EDS) AudiWorld 1996
Electronic differential lock, or EDS (german acronym for same), is not a differential lock as per usual. It uses the ABS sensors at driven wheels (i.e. left/right front on FWD, left/right front and left/right rear on quattro), to determine if one of the two wheels is spinning faster than the other. At some speed differential (approximately 25 mph / 40 km/h), the highly sophisticated fifth-generation ABS/EBV actually pulsates the brake momentarily at the spinning wheel, effectively transferring the torque through the open differential to the wheel with more traction. This system is effective, but due to the stress that it would create on the braking system, it is only used up to speeds of about 25 mph / 40km/h.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
in effect is there a claimed EDL for EACH of the front AND rear axles or just one that works on both axles?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

As was explained earlier, EDL uses the wheel brakes. With a center differential there's no way you're going to lock both front and rear differentials from any single wheel brake.
But that's A Good Thing...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.