Diy Haldex controller........Haldex Controller taken apart with pics

Ok guys.

Here are some hints to made a nice Haldex controller with a simple arduino board.

Well, inside the haldex valve body you will find a bipolar stepper motore that drives via a gear a spring loaded piston that is used to shut off the return oil pressure from the mechanical pump inside the haldex coupling.
The more the piston close the oil passage the more the pressure raises and more locking we will have on the haldex clutch.
Inside the valve body there is also a small plastic sensor that is used to measure oil temp.
This helps for calculations and corrections depending on the oil temp and to turn off the haldex clutch if the oil comes too hot.
For normal driving in these days were outside temp here is about 6 - 8C I see that oil temp goes around 22-26C in normal driving and start to raise to 30-35C if you send some power on the rear weels (but without doing drag racing).
Probably in extreme hot situations and hard driving oil can go over 80C and in fact this is the point were my haldex controller whatever the state is will go back to FWD until the oil temp goes below 60C

Well going back to stepper motor because as told before it is spring loaded to go in resting position when power is turned off (or any error occurs) we cant use a motor driver based on the L298N because this will provide continuos power to the stepper motor causing the motor became hot and damage will occur in few minutes of play (already happen to me).

If we drive the piston to the correct position using the L298 to engage the haldex clutch and then remove power to avoid motor burn the piston will go back to resting position and we have no power transfer to rear weels

Solution is use a stepper driver that have capability to give an holding current that is enough to keep piston in place and keep motor overheating
After an undefinied time of testing I find the best (and cheap) solution with these TB6560A board that sells for few euros on ebay

http://www.ebay.co.uk/itm/3-AMP-TB6...155942?hash=item2cacf2d326:g:PNIAAOSw6btXRCvZ

but you can buy whatever similar were you like

http://www.ebay.co.uk/itm/TB6560-3A...535159?hash=item25ad9cf6f7:g:QSMAAOSwFnFV90Ji

With this board we can set the driving current on the motor while moving and set the "holding" or "stop" current to be 20% or 50% of the driving current.
So for example we can set 1.0A current to move piston and then 0.2A current to keep it in position

Also it need only 2 pins from arduino to work because have a "STEP" and "DIR" driving sistem
This mean that pulsing on the "step" pin will cause motor to advance of 1 step, so if we give 10 pulses motor will do 10 steps
The "dir" pin sets the direction, if is low it goes in one direction (e.g. clockwise) if is high it will give in the other direction (e.g. counterclockwise)

With this board writing the software is more easy because only have to drive the two outputs and all the logic to combine current flow in the two windings of the motor is done by the TB6560A

 

Now going back to the piston in the valve body.

The pistons in the valve body takes 80 steps of the motor to do all is movement.
This mean that if we power up the board and assume te resting position to be 0 we can give 80 steps and the piston will not reach the end of travel.
Total travel if I remember is something around 85 -86 steps

Well the first 10 steps nothing happen this mean that from step 0 to 10 the piston moves but does not start to close the oil passage
between steps 10 and 60 the pistons closes the oil passage and we can start to give power to the rear weels.
Let's say that at 60 steps the passage is full closed but still some oil can pass due the clearance between the piston and its body.

Moving the piston from 60 to 80 steps will ensure the maximum possible torque transfer to the rear.

I have set the 100% transfer at 60 steps and I called 110% lock when piston is at 80 steps

Full lock is reacomended only in first gear for drag racing style starts.

Driving the car with the clutch full locked is not nice and car is not stable becuse I want to remember you the "quattro" system from audi does not have a central differential.
This mean that the difference of speed that occurs from front axle and rear axle have to be compensated from the haldex clutch and to do this there have to be always some slip.

After some test with my Golf (and it have some horsepower) I can say that a clutch locking between 20 and 50% is enough for fun, track and saturday night at the opera.

But if you have to do the quarter mile lock it at maximum and "pedal to the metal"

 

Ok now is time to see were wife want to go for dinner.
I have to check if this place have a parking were I can see the Golf while I have dinner

And again, sorry for my english

 

Are you having a mozzarella pizza?

 

Thanks Silvio for the info on the workings

I've just ordered the TB6560A so just need to get the program and wiring sorted I have the 16x2 LCD and arduino already

 

How much horsepower has you golf got then we need more info

 

No, yesterday there was a football derby and all the pizzeria were full because all the people want to eat pizza and wach TV (I hate football and I hate places were there is TV, if I want TV just stay at home) so we go in a place were they made nice greek cousin and Golf was parked just outside the window in front of me

I live in Naples, the place were pizza was created so sometimes is difficult to find the correct pizza in the correct place

 

The car have a long, long story that starts at mid '90 maybe I will start a thread with last built information.
Just to give you a idea I NEVER had drive my Golf with the stock ABF engine, I really did not know how a MK3 GTI 16V was to drive without turbo.......they really were sold without turbo?

Well, last time I put the Golf on dyno was in october 2013 to see how much power was left from the engine that was built in 2011 and try to optimize for a drag race done at the end of 2013.

Around 650hp alive from the original 720 of the 2011, when I opened engine just find 2 bent rods and a cracked cylinder head. Not so bad.

Here two videos of the dyno 10/2013

Boost was 2.8bar, redline 8750rpm

https://drive.google.com/open?id=0B0v98rfDMyASckp0YU93LXhBMDg
https://drive.google.com/open?id=0B0v98rfDMyASd2ktb25JeG5lUlk

After the last drag racing of the 2013 I noticed that there is no way to put the Golf power to the ground, exit speed on the 1/4 mile were quite high but time was a mess

So we decided to go to 4WD...........and another chapter of the Golf story began

The Golf NP era was closed........we needed the Golf NP4

And this is what happen now at friday night cruises when we leave

https://drive.google.com/open?id=0B0v98rfDMyASUEJLVzBaeEdfNkE

No more wheelspin (if boost below 2bar).........but you can set in FWD mode for fun

 

Look forward to the build thread ??

 

You really want to know all my secrets.......ok will see what can I do

 

If you need can give you suggestion for wiring and for the code, I think you have the haldex valve body so you can open and check rotation of the stepper motor to ensure correct piston movement before you put under the car

 

Alec (sparrow) has my stepper motor so Yes not in the car yet so can check

 

Thanks for joining up, Silvio.
You've already saved us a load of time, and a stepper motor. I have two boards at the office, one is a L298N, so I won't use that one. I'll see what the other one is.

We'll be splitting the case on the test unit I have from notenoughtime this week, so should have some results fairly soon.

 

Awesome project this! watching closely

 

Need to come in UK to test these Golfs........

 

Progress:



We went a bit too far, more to see what was there than anything else, but it's ready to be tested shortly. We reassembled it so that it's usable.

I didn't have the correct breakout board, so ordered a new one today. It will be here in the next day or so. However, I've got a week from hell, so won't be able to look at it until the weekend at the earliest.

 

Excellent! We know your busy mate crack on when you can
Thanks again

 

I remember something similar on my desk

 

It's here, from Everything Pi (8.95 delivered):



I'll get this working next week, and then look for a display of some sort.

 

Hello mr. Sparrow.
It seems that the first two switches departing from left are broken.......

Today I noticed one thing:
Remove gearbox for clutch service from 4x4 Golf is about 1 hour, remove gearbox from damn 'grale is about 1 day
https://drive.google.com/open?id=0B0v98rfDMyASTFNfaEZDM0lmWVU