# Haldex coupling and control discussion >>>>



## Marcus_Aurelius (Mar 1, 2012)

I'm starting this thread so we have a place to talk and discuss all things related to the Haldex coupling and control. 

(I'll update this post with basic function and schematics published on our Gen1 coupling and controller)


----------



## Marcus_Aurelius (Mar 1, 2012)

.


----------



## TheDeckMan (Sep 26, 2004)

Here we go!


----------



## ejg3855 (Sep 23, 2004)

*FV-QR*

Im in, I think I mentioned it earlier but for those of us that aren't looking for Dynamic Control (Smart System) I think this should be a pretty simple Arduino board and programming.

Even you guys who want those other inputs as part of the control would just need to do more work to program the unit. This could all be easily avoided if we had the definitions for the OE controller.

Max when you get a chance shoot me that PM with wiring diagrams.


----------



## warranty225cpe (Dec 3, 2008)

DeckManDubs said:


> Here we go!


My thoughts exactly. Waiting for the bomb to drop... opcorn:




:laugh:


----------



## racin2redline (Sep 25, 2008)

Here comes my distraction of the day! Can't wait


----------



## warranty225cpe (Dec 3, 2008)

racin2redline said:


> Here comes my distraction of the day! Can't wait


lol, been at work for an hour and have yet to do anything :laugh:


----------



## Marcus_Aurelius (Mar 1, 2012)

Let's just say that good progress was made, but no ball will be dropped until some good amount of testing is done. I'm already setting up for some AWD dyno runs that shows TQ split front/rear so the difference can be accurately measured between stock, competition, and the upgrade we've done so far. This way there is no guessing of what and how much is been achieved. 
*
Big thanks to the members of the community that have helped and volunteered to give me spare controllers to try stuff. Without you guys, none of the motivation, testing and breakthrough would have been possible. *:beer:


----------



## ejg3855 (Sep 23, 2004)

*FV-QR*

What updates do we have on deciphering the hex read out of the controller?



Marcus_Aurelius said:


> Yes, there is pre-charge pump (V181) mounted on the coupling housing that receives a 12v from the control unit as soon as 400 rpm is exceeded. The controller itself use a stepper motor (V184) that is geared to the regulating pin.
> 
> I believe that the supplied voltage to the stepper motor is not a constant one (haven't tested it, so don't quote me on that). For example, I have documentation from Haldex that shows how input from the fluid temp sensor (G249) is used, not only as a safety device (after fluid temp of 100*C is reached), but also to regulate the stepper motor based on fluid viscosity by varying the supplied voltage.
> 
> ...




Do we know what the control wave of that output to V184 is suppose to look like ? PWM ? Binary? Voltage? PM'ed


----------



## WhanAB (Jul 29, 2012)

*haldex ??*

on the Blue Haldex what is/was the actual split 70/30 60/40 when it was engaged ????

what was the main factor to have it engage ???

Thanks.........


----------



## 20v master (May 7, 2009)

WhanAB said:


> on the Blue Haldex what is/was the actual split 70/30 60/40 when it was engaged ????
> 
> what was the main factor to have it engage ???
> 
> Thanks.........


It is like stock and can be anywhere from 90/10 to 50/50, there is no set split. Wheel speed difference and throttle input are the main factors I'd imagine as the blue/orange try to be proactive instead of solely reacting based on wheel speed difference. 



ejg3855 said:


> Do we know what the control wave of that output to V184 is suppose to look like ? PWM ? Binary? Voltage? PM'ed


Isn't the stepper motor controlled by PWM?


----------



## vToe (Oct 19, 2003)

sub'd for content. opcorn:


----------



## AustinVaughan (Aug 23, 2008)

in for info :beer:


----------



## Marcus_Aurelius (Mar 1, 2012)

It was hard to locally find an AWD dyno that can show TQ and wheel speed difference between axles, but I found one. I have two modified controllers, a "street" and "race" versions to test and compare to stock and competition controllers. Thanks Mike (racin2redline) for providing a spare controller, and allowing his TT (with a competition controller) to be a test mule for all the testing. Stay tuned!


----------



## ModsTTand (Jul 8, 2009)

Thank you for updating , regarding the two modified controllers , were their software modified too or only mechanical modifications were done 

I guess i'll start looking for more defined wheels alignment for more active rear wheel setup ! more Grip FTW





Vroom Vroom


----------



## Brake_Dust (Sep 24, 2001)

Watching this one :thumbup:


----------



## Rford71 (Sep 1, 2011)

Great work guy!!👏


----------



## 1fast2liter (Apr 4, 2005)

Intrested

reply typed by trained monkeys


----------



## deathmetalscottie (Jun 4, 2007)

Subscribing! Another way to also approach building a smart controller is looking into how the big dog Mitus and Scooby (non-STI) controllers work.


----------



## sthmck (Jan 22, 2013)

Hey everyone I'm sorry to come in and start asking questions right off the bat. I haven't been on this forum in a while for lack of interesting threads. This just caught my eye after several months of me not paying attention and feel like I may have missed some of the build up that brought this thread into existence. If anyone feels like catching me up I would appreciate it.


----------



## misternoob (Oct 25, 2009)

sthmck said:


> Hey everyone I'm sorry to come in and start asking questions right off the bat. I haven't been on this forum in a while for lack of interesting threads. This just caught my eye after several months of me not paying attention and feel like I may have missed some of the build up that brought this thread into existence. If anyone feels like catching me up I would appreciate it.


http://forums.vwvortex.com/showthread.php?6132134-Your-Haldex-Works-Powertrak-Insert-Review 
^ Thats the start of it.


----------



## racin2redline (Sep 25, 2008)

If we could consolidate some information between these threads we cab have some valuable sticky information here too :beer:


----------



## deathmetalscottie (Jun 4, 2007)

I just had a stroke of genius! Maybe just a stroke, but what is stopping anyone (other than funds) from "creating" a "frankendex setup? I love programming but it almost seems like it would be more beneficial to utilize the programming readily available with adapted hardware. The differences between the gen 1 to gen 4 all seem to be based on the same " basic" design; whatever generation Haldex diff is connected to the rear diff of the vehicle by an output shaft and pinion. The real tech comes from the controller and the way oil pressure is built trhough the controller. Having a more proactive system by pretentioning the clutch, the ability to select different "biases" on the fly and being bale to add a mechanical LSD in the rear seems like the best way to go. So, what am I missing here?


----------



## ejg3855 (Sep 23, 2004)

We could with audrino, the problem that exists currently is no one has the controller defined.

Sent from my SAMSUNG-SGH-I337 using Tapatalk


----------



## RabbitTT (Nov 27, 2012)

Joining for interest.


----------



## carsluTT (Dec 31, 2004)

yepy...... now lets see the goodies


----------



## Longitudinal (Nov 13, 2004)

I am new to TT ownership, so maybe I am coming at this with ideas that have already been beaten to death. Please bear with me if that is the case.

What if the activation RPM of the pump were increased to 2000 RPM or so, where the 1.8T engine is making no useful power, then, above that RPM, the pump is engaged and something like the Powertrak module alllows full 50/50 engagement?


----------



## Marcus_Aurelius (Mar 1, 2012)

Longitudinal said:


> I am new to TT ownership, so maybe I am coming at this with ideas that have already been beaten to death. Please bear with me if that is the case.
> 
> What if the activation RPM of the pump were increased to 2000 RPM or so, where the 1.8T engine is making no useful power, then, above that RPM, the pump is engaged and something like the Powertrak module alllows full 50/50 engagement?


There is one pump, the pre-charge pump, and it's activated at 400 rpm. There is always pressure provided (with the engine running and no haldex-disabling faults). It's the controller that bypasses some of that pressure to the clutch pack via a stepper-motor activated pin that restricts/opens a pressure bypass valve depending on conditions determined by the control logic. 

Having a full "50/50" engagement isn't a desirable thing and a big step backward with such an advanced AWD system. The system (even in the first gen) is designed and works exceptionally well, it's the aggressiveness of the OEM control logic that gave the gen1 haldex a bad reputation. You get that control logic to be more aggressive or performance-oriented (via remapping that is widely available as of lately) and you have an AWD system that really performs well. 

IMO, forget about the Powertrack thing, save for a remap or that piggyback controller that will come out this summer.:beer:


----------



## TheDeckMan (Sep 26, 2004)

Marcus_Aurelius said:


> IMO, forget about the Powertrack thing, save for a remap or that piggyback controller that will come out this summer.:beer:


THIS!


----------



## Longitudinal (Nov 13, 2004)

Any possibility of a MAP input into the decision making process of a new controller? 

If I am under boost, I wouldn't mind if the computer assumed that things were about to start happening.


----------



## Marcus_Aurelius (Mar 1, 2012)

Are you saying implementing a pressure signal into the OEM control logic? Not easily feasible, and a quicker reacting mapping (although wheel spin based) will be all you need from the system. (BTW, we don't have a MAP sensor in these cars) 

The only controller I know at this point that uses a boost reference is the CRC performance standalone controller. It was built to use pressure as a primary signal for the cars that are converted to haldex gen1 couplings, but missing the ECU logic to control the system. 

I like the idea of having boost pressure as a reference because it would allow to make the system closer to being pro-active (imagine having the activating point of pressure reference set very low). However, I wouldn't want it to be the primary or only reference signal, as wheel spin and traction loss are still the main concern IMO.

http://www.crc-performance.com/inde...ldexsteuerung-beschreibung&catid=55&Itemid=88


----------



## ejg3855 (Sep 23, 2004)

*FV-QR*

MAx what is coming out this summer ?


----------



## Marcus_Aurelius (Mar 1, 2012)

Eric, HPA has a programmable piggyback controller that is scheduled to be released this summer (with various modes and apparently featuring a full user-programmable mode).


----------



## WhanAB (Jul 29, 2012)

*new items summer Haldex*


----------



## ejg3855 (Sep 23, 2004)

*FV-QR*

I would assume this HPA unit still requires the CAN system for all the inputs ?


----------



## 20v master (May 7, 2009)

ejg3855 said:


> I would assume this HPA unit still requires the CAN system for all the inputs ?


That would mean it wouldn't work on AMU's......didn't CAN show up on 225's with BEA in 2003?


----------



## Longitudinal (Nov 13, 2004)

Marcus_Aurelius said:


> Are you saying implementing a pressure signal into the OEM control logic? Not easily feasible, and a quicker reacting mapping (although wheel spin based) will be all you need from the system. (BTW, we don't have a MAP sensor in these cars)


Yes. I didn't know if the solution being ballyhooed here is a rework of the factory control module or a completely new module. A new construction module could have anything. I understand the limitations on a rework of the factory module.

Are you saying that the 1.8T engine management doesn't have a MAP sensor?


----------



## Marcus_Aurelius (Mar 1, 2012)

Longitudinal said:


> Are you saying that the 1.8T engine management doesn't have a MAP sensor?


Yes!


----------

