Haldex - for info

[NoggyDS3]

I've seen quite a lot of questions/discussion about Haldex and how it works on the forum recently.

Anyway, i came across a detailed haldex guide in pdf format tonight and thought it would answer a lot of people's questions and would be of interest to those of you who want to find out more about it!

Here you go!

http://www.r32oc.com/HALDEX.pdf

 

[1animal1]

good find mate, very interesting read

 

[Wicked666]

awesome link! didn't know it was made up of so many components!

 

[NoggyDS3]

Cheers guys!

Yea - it's quite a clever bit of kit!

 

[jojo]

awesome link! didn't know it was made up of so many components!

Which means great when it works, and expensive when it breaks! It's not so much that it's made of so many components, it just makes use of existing compenents on the car.

 

[Perplexer]

I've seen quite a lot of questions/discussion about Haldex and how it works on the forum recently.

Anyway, i came across a detailed haldex guide in pdf format tonight and thought it would answer a lot of people's questions and would be of interest to those of you who want to find out more about it!

Here you go!

http://www.r32oc.com/HALDEX.pdf

Fantastic - thanks!

 

[666markyboy]

so reading that guide then am i right in thinking that if the handbrake is on... then 4 wheel drive is disengaged ??? so you could click the handbrake 1 or 2 notches to operate the switch and not fully operate the brakes and you would be in 2WD ?? something i need to test

 

[jojo]

so reading that guide then am i right in thinking that if the handbrake is on... then 4 wheel drive is disengaged ??? so you could click the handbrake 1 or 2 notches to operate the switch and not fully operate the brakes and you would be in 2WD ?? something i need to test

Yes, I believe this can be done if your car has ESP, cos it doesn't work on my non ESP equipped S3.

 

[666markyboy]

well just been out out in my Quattro Sport with no ESP no button on the dash anyway so i presume not ESP pulled handbrake on 1 notch just enough to illuminate the parking light booted it from standing start and lit the tyres no problem... never done that before... knock the handbrake off again and back to mega grip..... interesting never knew that

 

[1animal1]

thats damn right bizare!! wonder what difference it would make to performance....if any

 

[666markyboy]

well to my engineering mind it would make no diff at all, the haldex is normally disengaged under normal circumstances... it monitors wheel speed and throttle position etc but unless it detects something amiss in the grip department it's in 2wd...

if your giving it some and the wheels start to spin then it starts feeding that lost energy to the rear wheels.... i guess if you think you can feather the clutch in 2wd on an agressive start so as to not quite spin the wheels then maybe you could have a slight advantage in that there are no transmition losses to the rear wheels but i doubt you would beat the computer and Haldex working together , at the end of the day your still lugging round the weight of that 4wd system so you might aswell use it.... interesting stuff though

 

[1animal1]

yeah, very interesting.....may be worth keeping this as a sticky....or putting the PDF link onto the sticky with the links on.... christ...it comes up often enough

 

[jojo]

The reason the Haldex disconnects when the handbrake is up, is so that you can lock the rear wheels when the car is in motion... handbrake turn anyone?
It's also handy for MOT testers doing the brake test on the rollers.

 

[NoggyDS3]

yeah, very interesting.....may be worth keeping this as a sticky....or putting the PDF link onto the sticky with the links on.... christ...it comes up often enough

Yea - happy for it to be a sticky if the mods want to arrange that?!

Like you say, questions on haldex come up all the time and this guide seems to provide a fair bit of info! I was looking for a guide for ages because there were so many doubts about how it actually worked.

Really glad i found it now!!

 

[Shy19s]

Really interesting read. thanks for posting this up.

 

[simch]

Seen it on ukmkivs!
useful though.

 

[ash_s3]

Very good read. suprising how much goes into making the car work!!