The Definitive 4wd Conversion thread

[s.g 0]

hi coxy

just a quick question , the rear syncro stuff are they all off the golf syncro (rear sub frame wishbones and drive shafts)

cheers

[CoxyLaad 0]

yes mate, well they can be. there are obviously other sources

 

i have mk2 golf drivshafts and outer cvs mated to 4motion inner cvs on the inside, and vr6 syncro rear wishbones on the outside.

[yellowslc 0]

Hey Mates.... Looooooooong time since I've been on here. Work is crazy busy though I've made a bit of progress on my own corrado. For those who don't know... 90 nugget yellow G60 converted to obd2 vr6 back in 1998.. together and apart a few times.. resprayed ferrari fly yellow back in 2000.. I gave up on the whole showcar bit back a year ago and decided a purpose built track car was the best route for me. Currently the car has a 14pt SCCA/Open Road chromeoly rollcage, fully triangulated/gussetted.. fuelsafe 17 gallon double urethane bladder fuel cell with bonded integral surge tank. Dutchdub built mk3 passat vr6 rear beam, 25mm swaybar, 280x22 rotors w/TTQ rear calipers, stoptech front brakes, new boot floor with bulkhead firebox to isolate the cell from the cabin (open road requirement, welded steel), cobra suzuka kevlar seats. The chassis is DONE, seam sealer completed.. epoxy primer.. etc. etc.. It currently awaits my visit to install the mockup engine and fabricated engine bits. 12v vr6 with Ross 82mm FI pistons (ceramic/dry film coated), manley 4340 chromeoly rods, full arp hardware, Ferrea superalloy valvetrain with Ti retainers/locks, and special alloy valvesprings (FI specification setup... fourseasonstuning.com hooked it up).. R32 gearbox, tilton/clutchmasters twin disk clutch. Racecraft fabrication 6:1 equal length SS turbo manifold, velocity stacked intake (you'll have to wait until PVW features the car to see this masterpiece).. blah blah blah. What is next? Verify dimensions for the IC/Rad/Fans/Boost tubes and fit the nose of the car back on. DSS is doing the axles as the car is currently 30 minutes from their shop in NC.

 

My current project:

Testing of the new haldex controller that I've been working on. Short list of specs/features:

1. Professionally built hardware to military specification. Reliability is key. In my eyes it's worth every penny of the cost.

2. Active control of the haldex coupling. Haldex designed this system to act and react, why bother doing anything else? Why create unsafe conditions on the roadcourse?

Inputs:

Throttle Position

Mass Air Pressure (boost/vacuum)

Wheel Speed

Vehicle Speed

Diff fluid temperature

Engine RPM

MAF

CAN buss communication is OPTIONAL - allows for use in newer cars or ones using the oem ECU. (many variables with this, contact to discuss further)

3. Fully mapable software- unfortunately this is not available to the public for multiple reasons. These units are flash loadable to the customers requirements. This prevents changes which may cause unsafe conditions.

4. Beta Testing. My 2003 audi TT Quattro and an HPA FT450 R32 will be used extensively to fine tune all programs. In addition, another TT setup for rally competition will be doing testing on gravel, ice, snow for additional data.

 

The beauty of this system is it's adjustability, this is also it's downside.

 

I am looking for additional beta testers to hop on board. The oem haldex module does need to be modified. This can be performed by the end user or I will be happy to do them for no additional cost. I can only guarantee proper operation if I do the work.

 

Phatty is chomping at the bit.. biggerbigben ? coxy?

 

Robert

[paul20v 0]

First time I've heard the Corrado rear axle described as "good" ...!

 

It's 1970's technology. It's the cause for the majority of the car's road noise and crashiness, and the only thing that makes it "different" from the others is those flexi bushes that essentially allow it to twist and give a little passive rear steer. Why do all modern cars use independent rear suspensions? It's not just because of the saved space!

 

Not having driven a VR with a trick diff, I can't really say whether it would be enough to keep 250+ lbft under control, but I doubt it. In a straight line maybe, but in the twisties I have a feeling that 4wd will always win. And modern UK traffic conditions give you far more requirement for 0-20 than 30-70, so I think I'd choose 4x4 if I had the power to do so.

theres nothing wrong with the basics of a beam axle all these cars with multilink suspension are an excuse for car manufacturers to mess about with things and as usuall make things over complicated more bushes to wear and more play and movement in things , only people it helps are mechanics /garages as they get paid to renew bushes a plenty ,

and on the main subject 4wd is great and i have had many quattro cars including UR quattro 20v turbo and a 320bhp s4 but i must say the 2wd corrado is as much fun ,but if you have the parts and competence do it ,it will be an intresting project :)

edit :or from what i am reading is a completed project how is it sticking it

[CoxyLaad 0]

very true paul, and I drive a standard VR corrado regularly. I agree its great fun, but when you start modifying engine performance, it strictly obeys the laws of diminishing returns it terms of the power you can actually put to the road. 4wd leaps ahead of 2wd in all but the most perfect conditions.

[paul20v 0]

very true paul, and I drive a standard VR corrado regularly. I agree its great fun, but when you start modifying engine performance, it strictly obeys the laws of diminishing returns it terms of the power you can actually put to the road. 4wd leaps ahead of 2wd in all but the most perfect conditions.

fair comment anything over 240bhp has to be 4wd otherwise it will just be a waste of power and tyre rubber :)

[Andywhammer 0]

Coming late to this thread but I thought I'd add my two penn'orth.. :)

 

I just sold my (Type 85) Audi 90 quattro that I'd owned for 8 years. In it's final guise it had a TSR Pack C head and Schrick cam (a good upgrade), Boge Turbo Gas shocks (excellent) and lowered springs (a mistake!).

 

Even though my quattro had only the old 50/50 split quattro system there was no doubt that 4WD brings big benefits - especially on wet or iffy roads (plenty of those in the UK). It's just so easy to plant your foot and squirt off when the 2WD brigade are spinning their wheels and you can apply so much more power so much earlier in the bends that it has to be faster A to B.

 

BUT, having said that, there are hundreds of things that go together to make a car "handle" and hundreds of things that make it fun to drive and 4WD is not essential to that. I'm currently thinking of a Corrado because I want something that's fun to drive above all, and I still have fond memories of my (original, proper) Mini Cooper S and my Alfasud and my Mk2 Golf GTI.... All that I've read suggests that the Corrado is a good-handling, fun car!

 

So, 4WD will make the car put down it's power better - no doubt about it - but it might not make it "better". :lol:

 

PS - The Audi TT is not a quattro - it's Haldex 4Motion. We quattro snobs think it should be badged as such.. :mrgreen:

[Anton Sobriquet 0]

Just arrived late into this thread and I've skipped quite a few pages, which I'll need to go back to and study.

 

I bought my VR6 Corrado with a view to converting to turbo or s/c R32 with an AWD system. I would not want 350 bhp+ in a FWD car unless I particularly wanted to go sideways every time into the nearest wall in slippery conditions, as Saab did when they tried going racing with turbos and 2 wheel drive years ago. I would have thought anywhere above 220 something bhp in a Corrado would be a rather pointless waste with just FWD.

 

Is there a straightforward route to AWD from a Haldex equipped 4-motion or TT? I'm wondering whether a more or less 'straight swap' out of a write-off is worth considering?

[CoxyLaad 0]

Fraid not mate.

 

fitting the syncro system from a rallye or other mk2 derivative is relatively straight forward, but the haldex back axle is too wide for the corrado.

The best route, and i speak from experience as i have done it, is to go with a syncro haldex hybrid. ie a syncro back axle with the haldex diff grafted in in place of the syncro item.

[Anton Sobriquet 0]

I'll study your previous posts then. Must say I've always fancied AWD in the Corrado.

 

As a matter of interest, in what way is the Haldex rear axle too wide (other than the obvious), ie what's the problem essentially in fitting it? Do you know if there's any technical or quasi-technical info anywhere about Haldex into Mk2/3? Can't seem to find anything much about this in the usual places.

[corradosyncro 0]

Hi

 

I am starting a site for 4wd corrado very basic early days at the moment if you would like your car featured please send a email ?

 

phattyvr6 is onboard

retroracer (canada) as well

 

http://www.corradosyncro.co.uk

 

Cheers paul

 

i will advertise the the corrado forum on my site cheers

[boost monkey 0]

Does anyone know how quickly Haldex changes from 2wd to 4wd electronically? (in milliseconds if possible)

 

And can you bypass this sensor and use a switch to change between the two modes?

[corradosyncro 0]

bit long but interesting

 

 

Before delving too deeply into 4MOTION, understand that there are two different versions, one for VW models equipped with longitudinal drivetrains, such as the Phaeton and Touareg, and another for those VW models with transverse engines, including Jetta and Passat. Phaeton and Touareg models use a Torsen center differential to control and deliver power to all four wheels. However, the transverse drivers are equipped with a high-performance Haldex clutch at the rear axle to accomplish the same task. And it is the latter system that we will concentrate on here. This is actually the second-generation 4MOTION; an earlier version was introduced on the Golf in some markets (but not the U.S.) in 1998. This new-generation all-wheel-drive system has been improved in many aspects. For example, the Haldex clutch unit mounted directly on the rear axle is now significantly more compact.

 

The most important technical element of 4MOTION is the latest generation wet-running (oil bath) Haldex multi-disc clutch. Compared to a straightforward mechanical Torsen

[boost monkey 0]

That's a brilliant post, cheers!

[corradosyncro 0]

The Electronic Control Unit (ECU), integrated into the housing of the Haldex LSC, has been developed and designed by Haldex and Siemens VDO Automotive. The ECU is designed and produced to endure the rough environments to which the drive-train is constantly subjected, including vibrations and thermal variations.

 

Click to enlargeECU Data

Infineon C167CS

16 bit RISC Controller

CPU clock 20 MHz

256 kB flash memory

 

The ECU controls a valve which directs the torque transfer characteristics, ranging from fully open to fully closed.

 

The open position is used during ABS operation and when Stability Control Systems are activated. The valve opens in less the 60 ms. The closed position is used when accelerating and driving on soft ground.

 

The software program determines the control of the coupling. It comprises two main parts: base software and application software.

 

Click to enlargeThe base software controls the internal functions of the Haldex LSC. One example is compensating for the variations in the viscosity of the oil, within the operating temperature.

 

The application software communicates with other active systems in the vehicle via a data bus. It determines the vehicle state with the help of the read signals. Examples of received signals are: engine torque, engine revs and wheel speeds. From this estimated vehicle state, the optimum torque distribution is determined in each condition.

If the input signals are lost due to a failure in another ECU, the Haldex LSC enters a limp home mode, maintaining AWD.

Every vehicle has its own requirement specification profile. This specification leads to different calibrations of the Haldex LSC. A multiple set of parameters are available in the software itself. Online, the application software will determine which set to use in the actual vehicle, e.g. estate or sports saloon.

 

no worries have some more info if you like

 

http://www.corradosyncro.co.uk

[boost monkey 0]

Great, thanks for the update.

 

I think it might be switchable, albeit by aftermarket means as some people in Germany have switchable 4wd on some mk2 golfs.

[datajon 0]

don't the Haldex LSC wear out over time, increase power only reduces service life of unit.

[corradosyncro 0]

hi you could say this about pretty much any thing to do with car tuning ?

 

i would much rather have 400bhp and have to buy a diff for couple of hundred pounds every 25,000 than have say 225bhp (s3/tt) and 60-70000

i know a few high powered cars and the haldex system is not the worry clutch tires cv joints seem to be the bits that explode he he

 

http://www.corradosyncro.co.uk

[junkie 0]

hahaha found it. :D

[CoxyLaad 0]

thread revival!

 

got me car on the road, and i know of a few others out there doing the same thing, so thought this might be the place for all your questions.

 

I am sure this used to be a sticky thread?

[blue95 0]

Camber! have took some pics and will be uploading them asap!

[CoxyLaad 0]

good plan.

 

I will do the same this morning. I actually think mine is within an acceptable operating range, but i would still like to dial some out.

[blue95 0]

Right mine is on 17" BBS, the middle of the rear arch is approx 61cm off the floor:

 

climatronic wiring-Golf from May 01.pdfcamber1.jpg[/attachment:3n6o1m2l]

2.8l 24v Climatronic system.pdfcamber2.jpg[/attachment:3n6o1m2l]

camber3.jpg[/attachment:3n6o1m2l]

[CoxyLaad 0]

well mine is at 62cm from the floor, and has about the same camber, I think I am going to have to make a device for measuring the camber properly.

[blue95 0]

well mine is at 62cm from the floor, and has about the same camber, I think I am going to have to make a device for measuring the camber properly.

 

Thinking about raising mine slightly as the suspension has settled a little now, going for a 4 wheel alignment next week, as the front wheels are way off.

 

Have to admit after doing well over 1000 miles in it the rears tyres seem to be wearing pretty well, even with the camber.