Playsatan

iTrader: (2)

I'm considering replacing my daily driver with a bog standard wrx or maybe even a quattro audi.

The car would be home serviced and while I know subaru's pretty well I've no idea how the audi system works. I've seen people metion oil and filter changes for the transmission, is it hydraulic, full time or what? Also are all quattro models the same?

Thanks in advance.

Simon K

I had an audi 2001 2.5 turbo diesel 4x4 allroad. Beaware of a torque converter issue on various model's automatic gearboxes. The VAG diagnostic system will show a torque pressure issue which is a nightmare to fix. Common to a lot of audis / vw;s !

SBK

hodgy0_2

don’t confuse the Haldex system with a Torsen differential technology equipped car

the A4,6,8s etc have a Torsen Diff -- which is the same basic design as the Subaru i.e. essentially a mechanical diff distributing the torque to all four wheels

the haldex as fitted to a A3's (and I think VW branded 4 motion) is totally different technology and i think uses fancy electronics and some sort of clutch system -- sure an Haldex expert will be along, but it is not 4x4 in the same way that a scooby/A4 Quattro is

Matteeboy

Haldex is sort of "pretend" 4WD - I had it in my R32 Golf. It works pretty well most of the time but your 4WD car will be FWD most of the time. That irked me!

Torsen is "proper" 4WD.

MattW

Don't write off Haldex, it's not a pretend system at all, in fact it's very clever. The later systems have an LSD so can distribute power left to right as well as forwards and back.

Haldex is never FWD only although perhaps only as much as 10% of torque is sent to the rear wheels where no slip is detected.

Haldex is used by a number of manufacturers, noteably the VAG group, Volvo, Saab and the Land Rover Freelander2.

Torsen is mechanical AWD, in the same way a valved computer is a "proper" computer

NotoriousREV

Matteeboy is totally incorrect about Haldex, as usual. Haldex is just a type of AWD system that uses a computer controlled clutch to distribute power rather than a mechanical clutch system. In some installations it is programmed to bias power distribution towards the front but not all. Early Haldex systems were slower to react (although, this was programmable) but the latest ones are much faster. You can even get remaps for them.

And don't forget, Lambourghini use the Haldex system in their cars and I don't remember any of them being slated for being FWD

Matteeboy

Ever owned a Haldex AWD car then? Thought not. Just regurgitating facts as usual while taking any opportunity for a snipe. Sad little amoeba.

NotoriousREV

Yes I've owned a Haldex car, I've worked on Haldex cars both mechanically and electronically and yes, I've used facts.

I have no doubt that the Golf is very FWD but it can be remapped. The reason I had a go at you is because we've had the exact same discussion on this board before and yet you insist on claiming that "Haldex is crap" because of your experience of one installation of it. FWD bias is not a feature of Haldex, it's feature of VAGs implementation of the Haldex system in that car.

ALi-B

iTrader: (1)

To answer to OP, no not all quattros are the same (quattro is a brand, not a technology). It either between torsen and Haldex. Of which both vary depending on year and model of car and if it auto or manual etc.

Haldex is a self contained elctro-hydraulic clutch unit contained in the differential unit (rear diff in Audis and VWs, Bugatti have it in the front diff, and Lambo...All VAG ) First gen Haldex (MK IV Golf, MkI A3) were not very good performance-wise. As the vehicle needed to be moving for it to work properly . Also a bitch to get at the filter on servicing. Gen II Haldex (MKV Golf) is improved and in contrast is pretty much maintenance free (and works better to boot).

Haldex service requirements set out by VW/Audi on gen I units (MKIV golf, MK1/8L Audi A3) say to change the oil every 20K (revised from 40K ) and the filter every 40K. GenII units just says to check every 40K mile and change/topup if needed (GenII units use different oil to Gen I). No mention of filter change is given. Refilling needs a length of hose and a little inventiveness (or buy the proper filling device - sod that ).


The A4 or A6 and A8 quattro in contrast has a torsen diff and front transaxle drivetrain layout not too different to an Impreza; engine longitudinally mounted and hung out in front of the gearbox (truth be known, Subaru probably copied the layout from Audi). Can't remember A4/A6 quatt servicing specifics off hand, but its nothing extravagant.

A4 quattros with the manual gearbox sometimes gain notchy gearchanges and not as slick as they should be (RS4 models are improved). Why that is and how to cure it, I don't know but something to be aware of. A3 is much more slick and cooperative; typically VAG like, but can get sloppy with age.

All VAGs need to use the appropriate VW approved oil to their own specification (VW 504.00, VW 506.00, VW 507.00 etc). Preferably use the long-life oil option, which is fully synth. And if you end up with a PD diesel make double sure it is the correct oil as PDs are fussy on engine oil. Service reminders on teh dash can be reset on most cars via the trip reset controls, but be aware that doing this will automatically revert a car on the variable longlife schedule to the fixed mile/time service schedule.

Gen I and Gen II haldex units can be modified via a upgraded Haldex controller, Gen II units benefit better as they will engage more on throttle application rather than wheel-slip. Simple bolt on modification. Although its fairly easy to get the **** out in wet/slippery conditions when driven in anger with a later generation II with the OE control unit as found on MKV golfs and 8P (MK2) Audi A3 (ESP must be turned off though).

Both generation Haldex, as well Torsion are pretty reliable, the only failure I've come across was a MKI haldex unit in a Golf that had ran low on oil over a long duration, which caused a jolting effect when making tight turns.

Biggest drivetrain concerns that affects all VAGs with manual gearboxes is dual mass flywheels. Not cheap, and they do fail prematurely, this affects all AWD and FWD models. DSG cars can suffer driveability issues and clunking when engaging gears.

Either way, both systems are far superior to the FWD alternative of the same chassis car. And very handy at this time of year (although my mum didn't appreciate me doing a doughnut in supermarket car park, whilst she was in the passenger seat ).

Steve vRS

Thanks for that informative and relevant post!

IHowever, i that in keeping with the Scoobynet spirit of trolling and ill informed opinion

Steve

ALi-B

iTrader: (1)

I'm so ill-informed that I can't even spell torsion/torsen properly.

Matteeboy

I may have used the horrific and infraction-worthy word "amoeba" but at least I can spell "Torsen..."

ALi-B

iTrader: (1)

An unfortunate bad habit gained via my applied mechanics modules at uni. Hence engineering words in the dictionary take precedence to words and branding made up for patenting reasons.

Infraction-worthy attitude maybe something to take on bored moreso than the word itself.

Matteeboy

In that case, I had a nice cold can of Carbonated Water, Caramel Sulphite Ammonia (E150d), Aspartame (E951), Acesulfame K (E950), Undefined Flavouring, Caffeine, Phosphoric Acid (E338), Citric Acid (E330) and Sodium Benzoate (E211) earlier.

zip106

Did you also have some E90335d by any chance?

fatscoobfella1

iTrader: (1)

Is that cockjuice ?

jeremy

Lets put it this way-- every comparison I've read by good drivers (Barker, Meaden, Harris etc) says the torsen is a more fluid acting system than ANY generation Haldex.

Evo compared a golf v r32 against a stock gti v in the rain and flatly stated from a handling perspective the plain fwd gti was more predicable and progressive to drive. Indeed they spoke of the haldex somewhat randomly shuffling power between wheels. So while indeed it may be true that the Haldex car once in steady state 4wd mode, does get more traction down than any front-driver its when the curves come that one can get into trouble applying the Haldex right.

BTW-same goes for the Haldex in the Insignia no-where near as pure and progressive to use as the torsen equivalent in the new S4.

Moral of the story seems to be that a decent spread of CONSTANT 4wd is always good to have- unless we are talking about the new GT_R which seems to defy what we know of 4wd. J

Matteeboy

No but I had a sip of E91335d...

Jeremy - someone speaking sense - at LAST!

LG John

I don't know all the technical aspects of haldex vs 'proper 4x4'. However, I have driven a Golf 4-motion with Haldex and a number of classic scoobies.

I personally thought the haldex was utter sh*t off the line by comparison. I launched it once and the front span for ages before there was some nasty clunking and the rears woke up. I can categorically say that my Impreza would have been long, long gone.

Also, at crail when I had my S2000 I had a lot of run against R32's. If I got my launch just right I could nearly match the 60ft time of the golfs. I often passing them by the top end of 2nd gear. The scoobies on the other hand I didn't pass until the last 3rd of the strip....if at all. Even Impreza's that were slower from a roll took so much of a lead from a dig.

In short, based on my own personal experience I'd try to avoid Haldex systems unless I had reason to believe the system was radically improved over the systems I've seen and used.

My mate, who owned the 4-motion and who lurks from time to time, subsequently bought a classic scooby and immediately remaked at how superior the 4wd system is.

richs2891

One of the annoyances I find with the haldex I have in my S3 is that traction control seems to want to fight the haldex system, reducing engine power when the haldex in the car is more than capable of sorting the problem out, leading to what could be described in extreme conditions as a shuffling of power between front and rear. With the traction control turned off - its so much better but it re enables itself every time start up.
I've driven another S3 with a later version of haldex and and a sports control and a lot lot better.
Overall I like the haldex system but Audi and to the same extent VW need to get it working better out of the factory and have more faith in its abilities, rather than hinder it with their traction control systems.
Not driven the very latest S4 but the RS4 I drove was very different to drive, as its a lot more rear wheel biased than my S3.

SaxoBoy the trick to launch a haldex equipped car - especially my S3 is to turn off the traction control if want a fast launch. I can get my S3 of the line much better than I could ever with my WRX or my STI.
Richard

LG John

IIRC it was off!

I find that last statement hard to believe. My 60ft times were absolutely epic in my 275bhp classic - never seen a haldex VAG car get even close. All 4 wheels instantly hooked up and she lifted off the line sideways - the limiting factor was the quality of the rubber on all four wheels and that alone.

richs2891

Intersting comments, Inital thoughts would be the weight differance - hurting intial take off - compare a classic to a bug or blob weight wise. VW / Audis are heavy - as are all newer cars. Never done the 60ft times etc as thinking more the traffic light sprint, so a fait bit longer
Maybe I'm more brutal with the Audi on take off than I ever was with the Subaru's (doubt it) or I got better at launching it (possibly) and to be fair my S3 is not exactly standard either !
Richard

Playsatan

iTrader: (2)

Thanks guys, great info.

Having read comments about servicing it I was worried that it was like running an ayc evo. Now I know it isn't as bad but some very interesting comments about living with t.

LG John

No idea how you were launching your scooby but a lot of people believe that it's best to hold high/full revs then side step the clutch. I find this not to be the most effective solution; although it may be with an upgraded clutch?

From memory it was best to be blipping the throttle between around 3500-4500 rpm and then 'pinging' the clutch up. I don't really know how do describe the motion in words. It's not a sidestep, it's almost like you slip it in very fast by quickly lifting the clutch but fractionally slower than if you just lifted from the peddle. Done correctly this allows the clutch to engage fully almost instantly and transfer all the torque to the wheels- only then do you snap to WOT; once the initial input has got the car moving. Often traction is broken and the car moves off with the rear usually breaking leftwards by a few degrees. Granted I've not been to a 1/4m strip in years and perhaps the game has moved on (GTR's, RS4's, etc?). However, back in the day very few cars could match a properly launched Impreza. The absolutely crazy thing is that if you 'pinged' it just right the forces within the transmission didn't actually feel crazy. Everything was VERY quick but smooth, so no sudden spikes in torque. I did a LOT of runs one day and my car and clutch were fine - I very much doubt that would have been the case if I was dialing up 6k and just dropping the clutch.

ALi-B

iTrader: (1)

I used to launch my scoob the same way as you SB. Done right and its pretty rapid off the mark that very few cars could match or better (rapid launches from standstill was always the Impreza's forté IMO).

Similar method works well with the R32. Infact the MKV r32 won't let you side step the clutch properly (same with many post 2005 VAGs - even the diesels). There is a delay valve that prevents the pedal from springing up (presumably a safety feature to protect the DMF from shock loads). You have to lift the clutch pedal to its biting point (whilst blipping at the desired launch revs), let it slip a few microseconds then lift off completely and simultaneously floor the throttle. Get it wrong and it bogs down big style.

I believe DSG cars are impossible to launch properly, they to seem bog down quite badly (unless there is a trick to it). One of the reasons why I avoided them - what's the point of AWD if it can't properly launch from standstill.

Those EVO reviews are on another planet IMO. In the real world, the Golf GTi doesn't hold a candle to an S3 or R32, especially in wet bends. Unless EVO consider the GTi's outer front wheel spinning away excess power as being more progressive (I personally consider it counter progressive, since its hindering progress ). If I found the GTi to better on the ones I test drove, I would have saved a fortune and bought a GTi instead.

Rich: Agree about the ESP/traction control; Just turn it off. It really does mess things up, I can feel it pre-emptively holding back engine power before there is any real wheelslip occuring (no flashing TC light). Having said that, I've caught A4 quattros doing the same thing (2.0TFSi was the most recent case - avoid, very dull Get a TDi instead ).

CupraT

So how does the Haldex compare to the 4wd drive system in the Nissans (the intelligent mode thingy)? Is it essentially the same thing?

NotoriousREV

Essentially, yes, except the R32-34 series are 100% RWD drive until the computer decides to feed in the fronts via the electronically controlled clutch. On a hard launch, you get some wheelspin then some power is moved to the fronts. This took me a while to get used to until I realised the only way is full revs and drop the clutch, anything less and it can bog down when the power is transferred.

I don't think there's much that can launch like a classic Scoob. My ratty old MY93 WRX with short gearing felt incredibly fast off the line and never wheelspan (not enough power )

Matteeboy

My R32 was very quick off the mark - in fact the 0-30 time is extremely (Jag XJ220) quick. The system was pretty good TBH - maybe it was incredibly grippy. I used to test the limits quite often (with a big run off area just in case) and was amazed at what it could do. But tragic in snow and very much a "road" system unlike that in Subarus, etc which are also useful for light off roading.

MattW

Try the new S4

richs2891

SB I dont have Subarus any more - an Audi S3 instead, but your right on the launch thing on the Subaru I was just simply side stepping the clutch hence not probably a great start, On the Audi just sort of releasing / ping it out, seem to work for me. The remap on mine seems to allow for better starts - but they claim nothing has been changed on that front !
VAG /Audis are getting very safetly paraniod now, on a MY2009 S3 you cant rev it above 3.5K in netural - one way to protect the clutch I suppose.

Richard