How much "power "can the haldex system handle ?

[dazmondo]

Does anyone have any idea whats the maximum bhp and torque the 4wd system can take before splitting at the seems,

im enquiring cause in the near future, a pacemaker may be attached to my beasts heart, i know HPA of north america do a excellent gearbox upgrade so im sure that somewhere in the UK the same can be achived.

Not looking forward to the MPG if itdoes happen but the grin should be worth it.

[Daemon]

HPA doesn't touch Haldex. HPA adds taller and stronger

gears, and a beefier clutch, but the drivetrain rear of

the front diff is totally stock. So the answer to

your question is, Haldex can handle however much power

you've got.

ian

[Rachel]

The official numbers vary between 1500 and 2000Nm torque - so at least 5 times what a std R32 puts out from the engine (320Nm).

The standard R32 gearbox is only rated to something like 346Nm, so the Haldex diff is pretty irrelevant in the power quest unless everything in front of it has been substantially beefed up first.

That is why part of the HPA (HGP) upgrade is new gearbox internals...

[Daemon]

Don't be misled by those torque numbers. Most people forget

that the transmission and final drive are torque multipliers.

The Haldex unit is downstream of the transmission

and the front diff. The prop shaft to the Haldex unit

turns at a 1 to 1 ratio with the rear drive axles.

If you're in first gear, which has a ratio of 3.36:1 and

the final drive ratio at the front diff is 4.24:1 then you

effectively have a torque multiplication factor of 14.25 to 1.

That means if the engine is producing 300Nm of

torque at the crank, it's putting out 4273 Nm of torque

at the front diff. Let's say it only takes 2000Nm to

spin the fron tires, that'll leave over 2200Nm of torque

going to the Haldex unit. In other words, even

a bone stock R32 can exceed the rated load capacity of

the Haldex unit in 1st gear, given the right traction

situation.

As you go up through the gears, the torque post-final-drive

decreases. Haldex also has hydraulic pressure overload

protection. When it reaches it's maximum load capacity, it

simply starts to bleed off extra pressure and clutch

pressure remains constant. This may mean some slippage

in the low to mid gears (2nd and 3rd), and front wheel spin

if you're putting down HPA stage II or EIP stage IV kind of

power numbers, but generally there's still enough torque

going to the ground that the accelleration is still pretty

mind blowing (0-60mph in 3.2 seconds.. quarter mile in

11.2-11.5, top speed over 200mph), all with the stock Haldex unit.

EIP has been researching ways to push the torque limits of

Haldex up, but then they're also putting down 600+fwhp.

Not a problem most folks have to face.

ian

[JaffaCake]

Ian, as usual you're a wealth of great knowledge. A true asset to this board...unlike me

[Skidmark]

In the VW Driver mag [Nov '04] they stated that the Haldex coupling fitted to the Mk5 4motion was capable of transmitting 3200Nm of torque to the diff....the previous version had a limit of 2000Nm.

It's quite alot in either case...

[JayR32]

Do you reckon it will handle the extra power a supercharger gives out?

The warranty on the cars runs out in May and I have been putting money on one side to treat myself to an up grade or 10

[mattcony]

Sure it will, there are loads of SC R's running round the USA now some with stage 1 and some with stage 2 conversions.

If I were you I would hold out a bit longer as the low priced turbo kits are about to start hitting the market now and seem to give more bang for your buck. EIP now have a UK distributor for there kit (can't find the link )

cheers

matt