All hail haldex!

T

thedooker

Registered User
Joined
Sep 7, 2013
Messages
156
Reaction score
134
Points
43
Location
Aberdeeen
Tonight I hit a bit of black ice in my S3. Before I knew what was going on the haldex had sorted me out and kept me on the road. if that was the 135i I would have been in the ditch.

It's the first time I have had to rely on a system to help me out like that (will not make a habbit of it) and I must say I was really, really impressed. 2 weeks in and my purchase decision has been 100% justified :D
 
  • Like
Reactions: d8ean, J6YAK, DrTS and 3 others
Reckon that was probably the ESP; haldex makes little difference if you're already skidding on black ice. Haldex is great though - being able to boot it round corners in the wet is hilarious fun.
 
thedooker said:
Tonight I hit a bit of black ice in my S3. Before I knew what was going on the haldex had sorted me out and kept me on the road. if that was the 135i I would have been in the ditch.

It's the first time I have had to rely on a system to help me out like that (will not make a habbit of it) and I must say I was really, really impressed. 2 weeks in and my purchase decision has been 100% justified :D
Click to expand...

Where are you hitting black ice?
Take it you are out-with Aberdeen? Not cold enough here for black ice surely.
 
Who cares if he hit ice or not or if it's haldex or esp that saved his bacon, fact is he's proud of his car and i like reading such positive experiences. GOOD JOB little s3 :).
 
  • Like
Reactions: GerberBaby, Scott, pat15312 and 5 others
Craig, it was the slug road ;)

It was definately haldex as it happened as I was exiting the corner. Front end went, then a bit sideways before the rear came round. Definately doesn't do it like that in a FWD car
 
Years ago my wife bought me a skid pan course up at Silverstone. Turned up to find them using FWD 1.9l diesel A4's as the car of choice. Initially I wasn't terribly impressed as I was hoping for an opportunity to learn to better control oversteer (I was driving an insane mid-engined RWD car at the time). However, as part of the training they jacked the hydraulic trolley fitted to the car right up so that there was virtually no grip left and let us experience how the ESP system works. It was very very impressive. When you turned the wheel it used differential braking on the individual wheels to cause the car to change direction. I was amazed at how controllable the car was even in such low-grip conditions. Not sure how much I really learnt during the day but this was definitely the part of the experience that impressed me the most.
 
I've done skid pan training and had rear wheel drive cars too. It may have been a combo of ESP and haldex but the car was definitely been driven from the rear wheels. The audi chassis doesn't do lift off oversteer to get the back end round.
 
Good to hear the technology in the car works. Between the quattro and the ESP both looking for grip it keeps the car on the road by the sounds of it.
 
thedooker said:
I've done skid pan training and had rear wheel drive cars too. It may have been a combo of ESP and haldex but the car was definitely been driven from the rear wheels. The audi chassis doesn't do lift off oversteer to get the back end round.
Click to expand...

I believe you buddy, wasn't suggesting you were wrong, just commenting on how good the ESP system is. As Cumbrian Bob says, it's good that the systems worked so well regardless of whether it was one, the other or both. The main thing is that you came out of it unscathed.

Now, where to do some Quattro skid pan training?
 
thedooker said:
Craig, it was the slug road ;)

It was definately haldex as it happened as I was exiting the corner. Front end went, then a bit sideways before the rear came round. Definately doesn't do it like that in a FWD car
Click to expand...

Ahhh the good old Slug road I'll bet you were having a bit of fun till that happened?
 
The other interesting thing about ESC/EDL on MQB - it aids cornering and under steer (to some extent):

...."and all configurations work with an Electronic Stabilisation Control (ESC) which includes an electronic differential lock. In fast driving through corners, this brakes the inside front wheel very slightly to minimise understeer and improve traction."


Audi A3 and S3 saloons strike out in a new direction < Latest news < About Audi
 
Alex C said:
does the haldex system on the new S3 ever engage when your foot isn't on the throttle? i.e. braking into a corner
Click to expand...


I don't think so. It operates using an electronic/hydraulic actuator type system which lets a clutch system off essentially and allows drive to the rear wheels from the prop shaft so you'd need to apply power to the prop shaft for it to work.
 
^not quite

Through a combination of messages from various sensors (throttle sensor, handbrake sensor etc) and CAN messages from the Engine ECU, ABS ECU etc. - the Haldex clutch pack can be engaged (or pre engaged) in many situations.

The Gen 4 & 5 Haldex unit has it's own electric pre charge pump, it doesn't rely on the prop for its hydraulic pressure.

You can be in throttle overrun and still have Haldex 4WD engaged (no active drive on the prop) - but the moment you touch the brakes or handbrake (or ESP intervenes) then the Haldex controller will disengage the clutch pack making the car FWD.


edit: It also disengages at low speeds (eg parking) to prevent transmission wind-up.
 
Last edited:
thedooker said:
Tonight I hit a bit of black ice in my S3. Before I knew what was going on the haldex had sorted me out and kept me on the road. if that was the 135i I would have been in the ditch.

It's the first time I have had to rely on a system to help me out like that (will not make a habbit of it) and I must say I was really, really impressed. 2 weeks in and my purchase decision has been 100% justified :D
Click to expand...

When you hit the ice did you accelerate or lift off? The clue is in the name - Quattro 4 wheel DRIVE system. If you were accelerating on black ice in order you use your Quattro 4 wheel DRIVE system - then you are brave or insane!
 
Daz Auto said:
When you hit the ice did you accelerate or lift off? The clue is in the name - Quattro 4 wheel DRIVE system. If you were accelerating on black ice in order you use your Quattro 4 wheel DRIVE system - then you are brave or insane!
Click to expand...

I have done that - hit ice unexpectedly, car started to slide sideways so I put it into second and booted it, grip came back and it pulled out of the slide (luckily in the right direction). This all happened at around 10-15 mph mind, so there was enough time to correct before hitting anything. Not sure I'd like my chances at proper speeds - you're in a ditch before you can even think about catching a slide on most roads.
 
Worst thing to do on ice is brake anyway either accelerate or lift off then power out
 
  • Like
Reactions: thedooker
Daz Auto said:
When you hit the ice did you accelerate or lift off? The clue is in the name - Quattro 4 wheel DRIVE system. If you were accelerating on black ice in order you use your Quattro 4 wheel DRIVE system - then you are brave or insane!
Click to expand...


From when I done skid pan training I was told not to hit the brakes in a skid (you don't want to have a wheel locked up at the point where it may find the grip that can save the skid). I was already at the apex of the corner starting to power out when I hit the ice. I lightly applied the throttle but did not boot it. This in turn gave the haldex (and ESP) system a chance to do what it is supposed to do and send power to where there is grip.
 
You must log in or register to reply here.
Top
Back