XDS related topics

Started this as I was slightly intrigued with what really went out with the XDS system. Why some say it breaks axles and eats through brake pads and others swear by it. Hope you all could help me answer my questions and possibly create a little documentation here to help others in the futre.

1. Does XDS brake unloaded wheel and as a result power goes to opposite wheel?

2. If the above is the case, isn't this a great inexpensive alternative to the more expensive LSD's and produce the same results? if the first question were true then XDS is practically the same as an LSD, they both stop the unloaded wheel from spinning?

3. Do you lose power when the unloaded wheels is stopped(via XDS) or is it really directed towards the opposite tire as with an LSD? I guess the same as #1 just asking if power is lost by using the brake or its actually transferred?

Thanks in advance. I really appreciate your support and if this is a repost or duplicate, pardon me in advance as I did search prior to entering these questions but had not positive yields.

PS- I tried XDS in strong and it does help the car turn in, at times though it felt a bit strong and felt as if it were stopping the power on corner exit. On the other hand I fully deactivated it and the car feels like a boat and the inside wheel spins like crazy when unloaded. I took a long curve and I felt the car push out a lot, centrifugal force was really felt. Cheers!!

Since we're already here mind as well ask what these channels do, for those who have tweaked them. Particularly interested in Hill-start assistant threshold which has a default value of 3%.
Counter steer support, default 'strong', how does it actually correct and is it related to torque steer?
Starting vibration reduction = what's this?

1. Yes.

2. It is a great and inexpensive alternative, but the results are not as good as an LSD.

3. Yes, the brake application is effectively reducing power getting to the ground, as some power is needed to resist against the brake. An LSD does not rely on the brakes, so you do not lose power for it to work.

xl1200r said:

1. Yes.

2. It is a great and inexpensive alternative, but the results are not as good as an LSD.

3. Yes, the brake application is effectively reducing power getting to the ground, as some power is needed to resist against the brake. An LSD does not rely on the brakes, so you do not lose power for it to work.

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Much appreciated it!

I've read this system works on the unloaded wheel as opposed to the LSD which works when there's wheel spin. Anyhow I'll play with the different settings and see which I like more. Definitely 'deactivated' isn't good.

Have you tried deactivated? Why is it not good? To me braking while under load isn't good. It isn't a real LSD. It may have an impact on the ACS being on even after deactivated.

Yomny said:

PS- I tried XDS in strong and it does help the car turn in, at times though it felt a bit strong and felt as if it were stopping the power on corner exit. On the other hand I fully deactivated it and the car feels like a boat and the inside wheel spins like crazy when unloaded. I took a long curve and I felt the car push out a lot, centrifugal force was really felt. Cheers!!

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I'm currently running on weak mode and its pretty good, i could tell where it helps turning, mid-corner or so, but it also doesn't brake the unloaded(inside) tire as much. I'll run it a bit more and see how it feels but so far i like it much more than 'strong' or 'deactivated'.

wy2sl0 said:

Have you tried deactivated? Why is it not good? To me braking while under load isn't good. It isn't a real LSD. It may have an impact on the ACS being on even after deactivated.

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If you could switch it around from default, strong or weak you'll feel the difference. It does help turning mid corner, or should i say, helps rotate the car. With it set to strong i felt i applied too much brake but with it fully deactivated the car understeered a lot and felt as if it had 0 inside grip. I know these "feelings" may not be factual but gives you an idea how the car behaves. I've read that ACS, ESC has nothing to do with XDS. Regardless i have my ECS and ACS set to allow FULL deactivation via VCDS. So when its fully off i know the only thing modulating the brakes is the XDS helping me turn.

Having the XDS deactivated not only understeers but if you happen go into boost with the inside tire unloaded, turning or any other conditions, it'll spin the tires like there's no tomorrow and you practically will coast out of a corner which to me is much undesired.

Hate to say it but without XDS, the GTI's understeer is horrible(IMO) but I still rather try to manage the understeer than deal with the power cut mid corner.

I say this because by the time the power is transferred from the unloaded tire to the outside, im already out of corner and all I feel is the braking of this inside wheel(lack of power). I feel the transition isn't quick enough from braking inside wheel to powering outside wheel. Mind you, this is street use and not in longer turns as you'd see in tracks.
Then again I could see how some would be concern with the XDS causing faster brake fade in these longer turns on a track environment.

sucks, should have gotten the PP lol.

So, if you *do* have a PP, are the VAQ diff and xds fighting each other?

six sigma said:

So, if you *do* have a PP, is the VAQ diff and xds fighting each other?

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Good question, wondering the same here.

One thing I did read is that XDS works on unloaded wheel and LSD is mostly, not to say only for when a certain amount of wheel slip is happening. Perhaps, just a guess, when wheel slip occurs the LSD does its job as opposed to XDS working just to help turn the car(reduce understeer) when inside tire is unloaded in turns.

Again just a guess, based on what I've felt driving my car, I could possibly be as far from the truth as it gets. Would really like to hear what someone with facts or better knowledge has to say.

FROM VW WEBSITE.


XDS Electronic Differential Lock



The XDS electronic differential lock is an extension of the familiar EDL function. However, XDS responds not to loss of traction but to the unloading of the front wheel on the inside of the corner when cornering fast. XDS applies pressure from the ESC hydraulics to the inside wheel to prevent it from spinning. This improves traction and reduces the tendency to understeer. The level of pressure applied ranges from approximately 5 to 15 bar. The impression when driving is similar to that of a limited-slip differential in toned-down form. The precise, one-sided build-up of brake pressure makes cornering even sportier, quicker and more accurate.

XDS should be controlling the rear axle while the VAQ does its thing in the front. Rather than slowing down the inner wheel the VAQ adds torque to the outside wheel if I understand it properly.

XDS is not doing anything to the rear axle. XDS and VAQ will work together. The two in conjunction are what gives the VAQ a torque vectoring effect. If there were no XDS, it would just be a smart locking diff.

Sorry, ESC will still be doing whatever it does on the rear axle.

I'd say this could give anyone a pretty good understanding of what these things do.

Found it I prefer XDS set to weak, this allows to still help turning, understeer, but doesn't apply hydraulic pressure hard enough to stop a good portion of the momentum carried out through a turn as I was encountering with it set to strong. This is all in street driving.

Yomny said:

I'd say this could give anyone a pretty good understanding of what these things do.

Found it I prefer XDS set to weak, this allows to still help turning, understeer, but doesn't apply hydraulic pressure hard enough to stop a good portion of the momentum carried out through a turn as I was encountering with it set to strong. This is all in street driving.

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I agree 100% with your statement.

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