They are running in the t3 class that doesn’t allow brake mods.
Any pictures of the rear brake ducting?
I doubt the rear needs ducting. The temps are a solid 250F lower.
I just wanted to see it. People always post pictures of the front brake ducting but I haven’t seen too many rear brake ducting systems.
here ya go west
Great find. Tempting.
A better caliper is not going to help you very much w/re to cooling.
I’m assuming you are running a BBK already. The only difference is caliper stiffness and pad area in some instances.
Assuming same rotor thickness and diameter, going to Brembo GTR isn’t going to make any major tangible difference in the ability to handle temps.
Someone on this board (I believe it was Psychotic) ran brake ducts with naca ducts on his B8 S4. Why not do that?
I’m honestly tempted to do the same… Otherwise, you have the Porsche control arm brake scoop option.
Failing all of the above, you can buy turbo wheels 
I actually know the dude who is selling it. Small world.
Yup, that was me. Better cooling is something that I’m exploring even on the RS5 (that has stock NACA ducts).
I’m still agonizing over this decision. I’m actually leaning back towards the carbon ceramic front kit from the RS5, with Pagid RSC2 pads. Alex @ europrice sells them right across the bay in Emoryville.
I did some research this morning and got all of the numbers together to justify the $9000 price of the Audi RS5 carbon ceramic front brake kit, over the alternatives.
380x32 Brembo slotted disk - 25.8 lbs
http://i61.tinypic.com/xawhtu.jpg
378x32 AP slotted disk - 24.2 lbs* (no pic)
- I own these and checked 2 years ago
380x32 Brembo drilled disk - 19.6 lbs (not suitable for track but useful reference)
http://i58.tinypic.com/mm2yl1.jpg
380x38 Audi carbon ceramic disk - 14.6 lbs
http://i59.tinypic.com/2rca58z.jpg
AP Racing caliper - 10.3 lbs
http://i58.tinypic.com/dw5sly.jpg
Brembo GT caliper - 11.7 lbs
http://i58.tinypic.com/9ulq1i.jpg
Brembo GT-R caliper - 10 lbs** (derived number - no actual pic)
** forged monobloc design is up to 2 pounds lighter
Audi Ceramic-disc-compatible Caliper - 13 lbs*** (derived number - no actual pic)
*** ceramic caliper on R8/RS5 is up to 2 pounds heavier than the standard caliper shared with R8/RS4
I think the best setup you could actually put together for the S4 is a Brembo GT-R caliper with 355x32 slotted rotors. I’m starting to believe I may have over-biased the front brakes on this car with the AP 380mm kit, and in turn overworked the front tires. I should be able to force the rears to participate more by adjusting the rebound (stiffer) on the rear damper. @boro will correct me if I’m wrong.
This 355mm rotor is 18.3 pounds, almost 7 pounds lighter than the massive 380mm disk.
find some used R8 or RS5 ceramics
install
sell used later on
Cheapest solution by far
AP racing should have biased the front system the same as stock, just resize the pistons depending on rotor size and application. Going to a 355mm disc seems like a downgrade, you’ll have a smaller surface area to absorb/dissipate the heat.
After some deep reflection, I’m thinking less is more. I’m going to be running a very capable and tunable suspension package, plus I have light wheels and Cup 2 (cup light?) tires. I should simply carry more speed through the turns. I’ll take some burden off of the system with a lot less rotational weight. And I’ll do my best to get the rear brakes to actually do some of the work.
The RS5 feels quite balanced to me with drilled 365mm rotors, and that’s more nose heavy car. I have faith that Brembo has done a better job with the brake pistons (force distribution) than AP, which in hindsight might have been a bit hamfisted.
Thanks for the tip. Sold.
Does anyone know the weight of the stock S4 calipers and rotors. Thanks.
The stock rotors are 23 pounds. The stock caliper is 17. This has a set of pads in it which are down to the backing plates:
http://tapatalk.imageshack.com/v2/14/11/29/38da12cb57e51ff9c576b5c169d69693.jpg
I checked with my brake pad guy and they don’t make the Pagid RSC pad for the Audi caliper. They only make the ceramic compatible race pad line for a couple of cars like the Ferrari F430. I’m not sure if they even have it for Porsche right now. Basically, if you put an RS-29 pad on a ceramic rotor you’ll ruin it as fast as an iron rotor. This is the dilemma.
I chose Brembo’s endurance pad, the RE10. It’s a step above the Pagid RS-29. It was expensive at around $795 for the front axle but should last a long time.