rear brakes upgrade

If you were to upgrade the rear brakes you would most certainly make the car unstable under braking as the brakes would remove the front brake bias.

you'd have to upgrade the fronts as well to overcome this, besides it's the front brakes that do most of the work anyway

you'd be better off buying grooved or drilled discs if you were after something more pleasing to the eye but they wouldnt make that much difference to braking performance so you keep the front brake bias
hope this helps:thumbsup:

I'd agree with scrupes, if you had the same sized rear disc, it would effectivly act as a handbrake, so when you went into a corner and decided to brake mid-way through, the backend might decide to try and overtake the front end, which wouldn't be ideal. The rough setup would be a bias of around 70% front and 30% rear. The front brakes should usually always have more braking power than the rear because the weight transfer during braking loads the front tyres and unloads the rear tyres.
The only way round it if you are really desperat to do this would be to add a dual master cylinder setup, which you would usually see on rally and race cars. This would then make it possible to separately control the front and rear brake bias. This option is expensive, and I wouldn't recommend it if you're just going for asthetics
Hope this is helpful

As i remember it: B5 variant S4 brakes won't fit a B5 A4 or A4 quattro as the hubs have differing caliper mounts on them. I have been told that the B6 S4 and A4's have the same mount points! this is not gospel though. You would also need the S4's calipers and caliper carriers, so if they are off a B6 S4 you may be lucky.

If you fitted both the front and rear brakes from a S4 to your car this would solve the balance problem as you have fitted the full set

I had B5 S4 front brakes on my B6 A4,really made a big difference in the braking performance.
If the B5 S4 ones wont fit a B5 A4 neither will the B6.