Audi URS6 PLUS “323mm brake discs and callipers”

[Andyh-R6S]

Are there any benefits in using the Audi URS6 PLUS “323mm brake discs and callipers” instead of the normal ‘314mm discs and callipers’?

After a trolling though “ETKA6”, it would appear that the only differences are obviously larger discs and a slightly different calliper. (i.e. suffix “A”). Everything else looks the same. Cheap (Ish) bigger (slightly, that is) brake mod perhaps, from the original Audi parts bins?

The only benefit I can see with the increased size of the disc is the potential to dissipate heat more effectively over a greater area, which should in turn give better (Ish) brake performance. Brake pads are the same and I would expect the callipers are the almost identical but slightly larger to accommodate the slightly bigger diameter disc.

Has any body done this conversion to a normal URS4/S6 and noticed any tangible benefits, etc?

[Rusty]

I've got 314s on my S2 and have thought about 323s but I've never found myself wanting with the 314s so decided not to bother spending the £150 or so to go larger.

If you need new discs and pads then it might be worth looking into the costs but I really wouldn't spend a fortune on it, better to buy a set of Porsche Monoblocks or similar, that really would improve the braking.

[Dirtylouie]

Are there any benefits in using the Audi URS6 PLUS “323mm brake discs and callipers” instead of the normal ‘314mm discs and callipers’?

After a trolling though “ETKA6”, it would appear that the only differences are obviously larger discs and a slightly different calliper. (i.e. suffix “A”). Everything else looks the same. Cheap (Ish) bigger (slightly, that is) brake mod perhaps, from the original Audi parts bins?

The only benefit I can see with the increased size of the disc is the potential to dissipate heat more effectively over a greater area, which should in turn give better (Ish) brake performance. Brake pads are the same and I would expect the callipers are the almost identical but slightly larger to accommodate the slightly bigger diameter disc.

Has any body done this conversion to a normal URS4/S6 and noticed any tangible benefits, etc?

AFAK The bigger outer rad of the disc - the bigger stopping ability the system has due to a "longer lever" the brake force is applied to. E.g try to stop a rotating bike wheel with your hand by the tyre or by trying to grab it next to the center.
Feel the difference?
But less then 1 cm difference between 314 and 323... i doubt you'll feel it.

[S2central.net]

IIRC - the 'A' suffix on those S6+ calipers means they are light alloy versions of the meaty 'HP2' caliper. Louies point on the greater moment of torque with larger disc on same caliper is very relevant but I'd say the improvement from a set of 4-pot calipers would be better than a slightly bigger disc. Never forget the excessive weight of bigger discs adds to rolling/transmission losses as you have to waste extra energy getting that extra mass in motion.


Paul

[Pembo]

I still think the brake pad material is the most important part of the brakes. Sure the swept area is key as too is how hard you press the pedal. I use Mintex Racing F4 compound now and it it brilliand. For reference I use RS2 calipers with 304mm discs on aluminium bells. Great combination.

[merlin's S4]

I don't think it's really worth bothering with the hassle for such a potentially small braking improvement. The standard S6 brakes aren't bad, certainly a lot better than the earlier ufo brake setup as fitted to the pre '94 S4s! If you're seriously considering an upgrade then Porsche Cayenne 6 pots are without doubt the way to go. They are all but a bolt on upgrade and boy do they bring the old Audi barge to a very rapid standstill.

[Pembo]

...opps forgot to mention that the brakes are now vacuum servo assisted using a combination of engine vacuum and electric vacuum pump and no 'bomb' anywhere to be seen.

[Rusty]

A set of Mintex Ctech 1144 or Ferodo DS2500 would see a good improvement. Does anyone believe that 4mm extra radius really makes that much difference? Can't say I do.