warcity

iTrader: (1)

I know the B8 S4 and possibly the B7 (I am not 100% sure) is advertised to have ventilated brakes, however the disc is neither slotted nor drilled.

Can someone explain to me how the breaks are ventilated?

Thank you.

cheeba

The ventilation is by way of air channels cast in between the rotor surfaces. As the rotor spins, air is drawn through the disc, due to the vane shape of the air channels, to cool it. Most modern vehicles have vented front brake rotors (and often rears as well), other than some smaller, slower vehicles.

This image pretty much explains it.

Axel

Yup, although Audi's B7 stock rotors' vanes aren't directional. They're just straight (i.e. perpendicular to the outer edge).

cheeba

Thanks Axel - there is a significant difference between the two, so it's definitely worth noting!

I should have said that many rotors have radial vanes, rather than directional vanes! Note that the directionally vaned rotors should be installed on the appropriate side of the vehicle as well.

warcity

iTrader: (1)

This is fantastic information and it explains it perfectly. Thank you both.

MadmaxS4Audi

Like all the other models wore!
they have a wind diverter, and also a split rotor that alows air to flow between the two sides of it.
That is it.
Has nothing to do with the after market drilled and sloted rotors that i recomend as a replacement.
I have had those in all my cars and they do make a diference!

warcity

iTrader: (1)

Yes thank you. I saw in the picture that was posted a few months back.