DSA Haldex controller for Superb III AWD

[newbie69]

After my recent contemplation about whether I should stick with the car beyond the upcoming 2yr mark and continue bringing it more to my like, or sell up and try something different, the conclusion was to go with the former option at least till it's 3-4 years old before reconsidering again.

One area I always felt it's hard to make a real difference is the inherent behaviour/dynamics of the car during cornering. Which is why when I heard about Haldex controllers being used from some MQB owners (mostly Audi TT-RS) with promising results I decided I had to find out for myself, also as I haven't heard of anyone having explored the impact of such a solution on a Superb yet.
After some search I decided to go with DSA mostly due to the background of the developer (previously related with a certain AWD technology of a certain very relevant German manufacturer...), the controller development and tuning done in collaboration with a known German rally racer and the experiences of owners using it that I could read about.


Installation:

The controller itself is like a small external 2.5" HD, roughly around 15mm x 100mm x 70mm.



It connects to the Haldex below the rear left seat and on it is connected a touch screen from which the parameters and different modes are accessed. Installation is very simple as soon as you can figure out how to take off the rear seat bench. After you've unclipped it from the two main clips (they didn't need replacing afterwards as suggested in the service manual) are off there's two brackets (one at each side) that keep the bench down which need a particular way of  pushing to go out. Push towards the back of the car and downwards, that way they'll be able to release and the bench can come off.

There is the option to fix the controller on the carpet via 3M tape (supplied) that bites into the carpet (kind of opposite to Velcro), but as it is so small I figured I could queeze it in below the seat foam for a cleaner installation. It seems like there's enough compliance in there to leave it in even if a passenger sits above. Regarding the control screen, it is not needed to be always connected after you've set it up to your like but untill setting up or for permanent use you can route it somewhere close to the driver's seat.

In the photo below I lift the seat slightly to show the controller below it (not really visible), and the cable going out to the left side of the car, tucked away in that plastic panel which has just enough play to host it nicely until the front dash
 


It then goes up and via the small cubby, over the steering column and in the little centre bottom cubby:








Not invisible for sure but I can live with it being something temporary as I said, once I have experimented with all options I guess I will settle with a setup and probably just disconnect the screen all-together, or I can try to leave permanenently inside the left cubby which does not allow the cable to be visible at all, just that for now I needed it to be somewhere within direct reach.




Settings:

The controller comes with preset values which you can modify to your preference. For starters, the controller is only activated when switching to ESP SPORT or ESP OFF. I have coded my ESP to immediately switch to ESP Sport with one push of the button, and full ESP OFF  when holding the button pressed for 2-3 seconds. Regardless of coding, you don't have to worry about forgetting in an aggressive setup during daily driving as the ESP defaults to ON (and thus the controller being OFF) every time the car starts up. 

The main parameters are the Minimum and Maximum locking values of the clutch (set between 0-100%) that override the stock values. The minimum locking value set is disregarded (locking is reduced 0-10%) when coming to a stop and when creeping forward.

Another feature is the steering angle reduce factor (menus are all in German for now). By activating this, instead of having a fixed minimum locking of say 60% at all times, the locking percentage is allowed to drop below the minimum locking value as soon as the steering wheel stops being straight, and the ratio at which this happens can be set from 1 (very slow and little reduction) to 20 (immediate reduction of a larger extent).

There's also an option to run the car in FWD mode. I tried that just to remind myself of the misery of my 370bhp GTI in the wet or in general on any road/condition below 60km/h, foot down and... yes, wheelspin bonanza... I also remembered why I had said I won't ever own another FWD car above 250bhp, let alone closer to 400...

You can also choose to keep the rear axle engaged during braking (as stock, Haldex disengages the rear axle when brakes are applied), this would work well on track I imagine.

Finally there's real-time monitoring of the percentage of locking, to understand exactly what's going on and how the parameters affect operation, as well as of engine rpm, torque, oil and coolant temps.


*** A note about locking values: The min/max locking values can be set up to 100%. Setting both at 100% means obviously the clutch is fully engaged at all times. This should NOT be confused with the actual torque split taking place though. Due to the design of the Haldex, there is no way to ever have more than 50% torque at the rear axle because if rear is fully engaged (100%), then both axles share torque equally (50-50).  I am thus concluding that any locking value seen at any point, should translate, at best, to half of it in terms of Torque % arriving to the rear axle (minus drivetrain losses where they occur). Still, a greater rear drive bias than the stock management for sure than only momentarily increases clutch locking to anything over 20-30% as I could see from my testing with the controller in stock mode.



Driving:

As expected, there is no difference under normal driving. This is not a suspension modification that you'll feel as soon as you drove a few meters. However, start using the throttle around a corner and you realize immediately there is unusual agility and willingness from the car to rotate, much more than you ever thought the car had to offer. Before, using more throttle than seemed appropriate for sticking to your track, resulted in fighting with the steering wheel to turn the front end of the car towards the inside of the corner. This is now gone.
Up to a point it almost feels as if you've activated some "turning assist" that rotates the rear and keeps you on track but allowing  you to accelerate even more at the same time. You simply corner faster. Over-do it, and the tail now easily steps out. Very manageable with a bit of opposite lock and throttle modulation but it will shock you the first few times simply because the car could never do something like that before. It put some big smiles up on my face for sure.
I also believe a thicker rear arb as the one I run accentuates the effect, so be prepared, especially when you've set up a large minimum locking value and no/very little steering angle reduction...



Impressions:

This is an improvement making itself noticeable and appreciated during fast driving (and I don't mean in a straight line). A track is where it would really shine or the right type of b-roads. Used wisely it makes the car faster and more involving, more playful. Used not so wisely it makes it just fun or silly, or potentially dangerous if you don't know what you're doing.

So far for me, the Haldex cars I'd driven (all 5th gen) were great point to point cars. Traction under all conditions but not able to carry much speed around the corner neither being particularly involving. The approach to drive them fast was moderate corner entry, steady throttle till the apex or even till a little after it, and then flooring it just as you touch the corner exit. Very one-dimensional and "automated" so to speak. With the controller, they are still no RWD beasts but they can become something better, more satisfying. The way the car responds now you can start applying throttle much earlier without the car washing wide but actually rotating where you're pointing and going even faster without scrubbing speed off. Or you can over-do it ever so slightly (when conditions allow) in order to have some fun around corners. It allows you to take an approach that was previously not accesible with any other modification and even if can only get use of it rarely, it feels very good to have it at my disposal.

PS. I do need to do a proactive Haldex oil change now just to be on the safe side.

PS.2 My rear tires are not going to be very happy with this mod...

Edited 23 November, 2020 by newbie69

[Ootohere]

http://briskoda.net/forums/topic/485980-haldex-how-to-control-your-haldex-vid-at-your-own-risk

 

[newbie69]

5 minutes ago, e-Roottoot said:

http://briskoda.net/forums/topic/485980-haldex-how-to-control-your-haldex-vid-at-your-own-risk

 

Yeap that's the VdV controller. Similar in principle but there's a few differences, to my understanding, in the way the system enforces the locking values and how much deviation it allows from them.

Regarding reliability, I spoke with a couple of owners that have really been beating their cars on track and running close to 700Nm (modded TT-RS) with the DSA controller, which is nowhere near the occasional usage I will be asking from mine, and they have had no issues yet.

Another thing which I found out during monitoring the behaviour of the stock system, and surprised me, is that contrary to what people (myself included) believe, there is quite some locking of the rear axle taking place even in stock form when you use the throttle around a corner. In some cases even, the locking requested from the stock management was surpassing my minimum locking value (60%) momentarily. Surely, with the controller you are requesting more locking more often (depending on your settings also) but my point is it's not as if the stock system leaves the rear axle alone around corners, far from it.

 

[newbie69]

Forgot to say the DSA unit ships with a full replacement plastic cover (the one for sealing the cabin from the outside) with an integrated cable for the controller. It is the OEM part (same part number) but pre-modified to host the extra cable needed.

Like this you only remove the stock grommet with the stock wiring loom and re-fit it into the replacement cover without the need to modify anything or leave holes to the outside of the car.

A detail that showed attention to the installation.

[Roscio]

Very interesting, I have also been interested in a haldex controller for quite some time now.
A curiosity, apart from having chosen DSA for the developer's background, did you still evaluate other manufacturers?
In any case, your first feedback is very interesting.
I am waiting to know what your final setting will be...

 

10 hours ago, newbie69 said:

I have coded my ESP to immediately switch to ESP Sport with one push of the button, and full ESP OFF  when holding the button pressed for 2-3 seconds.

 

Can you please explain me how did you set a full esp off?

 

10 hours ago, newbie69 said:

PS.2 My rear tires are not going to be very happy with this mod...

...very interesting!!

[Redboy]

All very interesting for track use. The standard car is good enough for everyday  use. Point to point journeys on Britains busy and battered roads now take longer than 30 years ago...if you don't want endorsements on your licence. 

[newbie69]

3 hours ago, Roscio said:

Very interesting, I have also been interested in a haldex controller for quite some time now.
A curiosity, apart from having chosen DSA for the developer's background, did you still evaluate other manufacturers?
In any case, your first feedback is very interesting.
I am waiting to know what your final setting will be...

 

 

Can you please explain me how did you set a full esp off?

 

...very interesting!!

This is a rather special tuning field and there's no "back to back" comparisons really to evaluate fully as with other modifications, so I did as much as I could by finding out where (in what cars and for what sort of driving) they have been used, contacting owners and finding out how each controller can be set up.
I liked the DSA offering for a number of reasons, a very important one being that the car still always drives as stock by default, but if you want more rear wheel bias you can simply push the ESP Sport button, that's a very OEM integration.
I also liked that it respects the stock decoupling in a number of occasions despite what you set up and that essentially, it amplifies an already built-in and exercised feature of the stock system (rear axle engagement), rather than introduce something completely different.


For changing the ESP button operation from the stock: TCS OFF (short press) / ESP SPORT  (long press)   to:  ESP SPORT (short press) / ESP OFF (long press):

* Mine is a MY19, don't blame me if it doesn't work on yours *  (speaking in general here)

Module 03 Brakes
"Long coding"
Locate "Byte 29" and change value from "A9" to "A8"

Dash will show a few errors momentarily, like no Brake servo available, as with other adaptations in the Brakes module, turn ignition off and on and they will be gone.

*** From what I have read you can also change it to "A6" and this is the true ESP OFF option (even though A8 also results in saying ESP OFF but I found out after I had done mine and haven't got round to try it yet.***


I didn't care about ESP OFF in particular, I actually wanted to be able to switch to ESP Sport (and Haldex controller ON) immediately with one push of the ESP button instead of long pressing. In stock form sometimes you realize you've already pressed it once, so pressing it reverts to being ON, then you long press again to switch to ESP SPORT, too much hassle for no reason, I never found TCS OFF useful anyway, I either drive with ESP ON or with ESP SPORT if i want to have some fun.

Edited 24 November, 2020 by newbie69

[newbie69]

1 hour ago, Redboy said:

All very interesting for track use. The standard car is good enough for everyday  use. Point to point journeys on Britains busy and battered roads now take longer than 30 years ago...if you don't want endorsements on your licence. 

I suspect that's more up to each owner and their use of the car.  Agreed that even for me who was after an extra level of playfulness and adjustability, I won't have the chance to exploit it that often on the typical public roads. I would have to "chase" these conditions (right place, right time, right environment) to be in place so it's more of a luxury.
For track use it would be excellent and with all the modifications I have done and plan to do, going back to the track is not ruled out (need better brakes first).

Till then, it will mostly serve for the occasional "sensible" play, like for example (this is a completely theoretical situation), a tight, low speed round-about in Swedish suburbs, at mid-night, after it's rained, you can get round at least half of it with continuous opposite lock... Not as intense, intimidating or hard to manage as with a RWD, but still an extra amount of fun the stock car was not able to provide.

Edited 24 November, 2020 by newbie69

[facet edge]

5 hours ago, Redboy said:

All very interesting for track use. The standard car is good enough for everyday  use. Point to point journeys on Britains busy and battered roads now take longer than 30 years ago...if you don't want endorsements on your licence. 

And the other thing about going faster round corners is you quite often can't see far enough ahead at reasonable speeds.

[newbie69]

4 minutes ago, facet edge said:

And the other thing about going faster round corners is you quite often can't see far enough ahead at reasonable speeds.

Not the ideal occasion for more throttle then!

One good thing about south Sweden being so flat though is you can at least ensure visibility for miles  

Hoping we'll get a bit of snow this year, last year there was none where I live, now I can only guess that would make for an interesting occasion with a Haldex controller on  

[Redboy]

1 hour ago, newbie69 said:

Not the ideal occasion for more throttle then!

One good thing about south Sweden being so flat though is you can at least ensure visibility for miles  

Hoping we'll get a bit of snow this year, last year there was none where I live, now I can only guess that would make for an interesting occasion with a Haldex controller on  

Lincolnshire is flat unfortunately, round the rural bends in this part of the world,  usually B roads, it's often hedgerows, trees, tractors, horses, spiced up  with grain and mud to endanger motorcyclists. You can read the road  signs, see the church spires and telegraph poles to anticipate the bends,  but not see the tractor and trailer pulling out just around the blind part of the corner.  

[newbie69]

26 minutes ago, Redboy said:

Lincolnshire is flat unfortunately, round the rural bends in this part of the world,  usually B roads, it's often hedgerows, trees, tractors, horses, spiced up  with grain and mud to endanger motorcyclists. You can read the road  signs, see the church spires and telegraph poles to anticipate the bends,  but not see the tractor and trailer pulling out just around the blind part of the corner.  

Well here I need to drive at least 30min to find a proper twisty b-road to begin with, everything is so annoyingly connected via straight lines...