Brake Question - Rotor sizes

[Roadie73]

Just a quick question on rotor sizes. I've checked the FAQs, and it states the fronts for a B5 S4 are 321mm dia, while the B7 A4 are 320mm dia.

I'm assuming that a 1mm difference isn't really important, (seeing as they are going on a B6 A4) but would like confirmation - especially when the B5 S4 rotors can be had for less $$$ (from Adam's rotor buy thread)

TIA,

Nick

[pondside36]

You need to buy the rotors that match your calipers..shoot adam a pm and he'll hook you up, I bought mine for $300 for all four

[akaEsCo01]

IIRC the B5 S4 rotors are also thicker so they would not work with the B6 caliper

[Roadie73]

Hmm - now I'm confused. Per the FAQ, the B5 S4 is 321mm x 30mm, while the B7 A4 is 320mm x 30mm - I would have thought that they would have been interchangeable, as the caliper would only be .5mm off.

Does anyone know for sure?

[Roadie73]

Now I'm even more confused....

Checking the ECS website, they state both the B5 S4 fronts and B7 A4 fronts are 321mm x 30mm...

So, if that's true, the same rotors will work with either the B5 S4 or B7 A4 calipers....

Secondly, which is the prefered caliper between the two? The FAQ states the B7 A4 is prefered - is this due to the B5 S4 HP2 calipers being larger, and having the 4 pad / 2 piston set up? Or is it something else??

Anyone? Help!!!