I'm sorry, but the 15% speed difference only occurs when the front wheels are spinning!
Theres no two ways about it, I love the S3, but you cannot deny that it is essentially front wheel drive until the front wheels start slipping, at which point the back wheels get power.
Go drive one to find out, it's just like a FWD!
Not true at all.
I got my S3 when I still had my K03sport golf running fwd about 230hp.
Totally different car in every situation, the golf could light its front up all the time, lift of oversteer as it has a beam rear axle and big arb, the s3 drove nothing like it. S3 was ballistic out of junctions, wet or dry, just drop the clutch. Handled totally differently due in no small part to the independant rear suspension.
ANY 4wd car will drive like a 2wd car until an wheel slips. Drive an old landrover up the road at 30mph in the dry, it feels like any 2wd car at same speed.
So ANY 4wd car only comes into its own when traction of some form is lost, that is the whole point of it.
Having 4wd of any sort allows more torque and power to be transmitted to the road without losing traction, as it is split ebtween two axles.
If anyone actually cares if an s3 or tqs or r32 /4mo is 4wd, or 4wd when traction is lost, well it IS 4wd. You can tell this by putting one on a two post ramp and starting it up, putting it in gear and letting out the clutch..........you will see all 4 wheels turning, ie being driven, all at the same speed all at the same rate, not "slip" or loss of traction.
The difference in the split betwen the axles is not power, or speed, (generally although the haldex alters its clutch effect when these parameters do kick in), the main difference is the torque transmitted to the rear axle is generally lower than the front, and in crusie, no slip driving, (not accelerating) it is pretty mcuh 10% rear torque, 90% front.
As you accelerate, and the engine power and more importantly torque incrase, the torque transfered to the rear increases. The haldex controller makes the rate of transfer of this torque vary depending on many many factors including traction, wheel speed difference, rate of torque increase, total torque being produced by the motor, and trottle position / rate of change of throttle position. The haldex perfomance controller merely increases the amount of time that more of the torque than the stock 10% is transfered to the rear. It still takes all the inputs, but transfers more torque in more situations.
I have not bothered with a haldex controller as I find the stock system perfectly adequate on my car. Mind you I have a far higher torque figure to stock, the throttle potentiometer has been recalibrated during the remap, and this has reduced whgat was a discernable "shunt" as torque was trasfered tl the abck end before the engine mods.
But anyone who thinks it does not work is wrong. The system does work, it's extremely clever and bearing in mind 99% of drivers never managed to unstick a car on big fat modern tyres, the benefits of lower drag and transmission losses in most situations far outweigh an extremely short "delay" that 99% of people would never even notice nor care about!
My car runs 330hp, 350ftlb, with sorted suspension and decent tyres and is in a different league traction and handlingwise to my 230hp, 240lbft FWD golf. The S3 is extremely planted, hadly ever gets outs of shape, and accelleration and traction from the apex of a roundabout in wet or dry just takes the pxxs out of 99% of the machinery out there on the roads!
FWD is fun enough my golf was ahoot to drive and great fun and very quick on track, but it was loose, and most corners on track were just one big 100mph slide. Traction off chicanes and hairpins was poor, compared to the S3 which still slides but nowhere near as much and wil give on the mereest of chirps of the tyres when side stepping the clutch at 4500 revs in first! !!
So toally different systems, but even if the haldex knockers who say its fwd until traction is lost are correct (and they aint!), why does that cause any problems!! ??
An Evo is 0wd when it is parked up in a car park..........the argument is about as relevent!
one of the best threads ive ever read!! 
beep beep
