Audios S4

I have am looking for some realistic input as to what is working for a B5 S4 brake upgrade. I am looking to aggressively track my car. I am looking to put brakes on that will handle real threshold braking and not over heat and cause me problems. I have considered the 07/08 RS4 8 piston brakes but haven't really heard of any real track feed back. Brembo's GT series seem to expensive. Any body out there with some input?

shawnoc2003

Any six piston caliper with floating rotors and Dot 4 fluid is going to be better than what is on the car right now in terms of heat soak.

The cheapest option used to be the Porsche Cayenne calipers with floating rotors (check out ECS Tuning)

Audios S4

I have access to the 8 piston 07/08 RS4 front brakes set calipers and rotors for about 2,100.00 new from Audi. I am concerned about the 4 puck pad system as apposed to the 2 pad system that all the Brembo, Stop-tech and Alcan use, but I am saving about 1,000.00 - 1,500.00 with the RS4 set up to comparable 14.5" systems with floating rotors. I have enough track time behind me to know I will be using these brakes hard. There are after market high temp pads available for track use with the 8 piston system off the RS4s. Is this a good idea or am I missing something about the 4 pad system?

shawnoc2003

If your using the brakes hard at the track you really need floating rotors. I'd worry less about the 4 pad vs 2 pad issue. Floating rotors really drive up the cost of a kit so that's why the Brembos are so much more.

ECS Tuning-Audi

Rotors are definitely going to play a big roll in being a heat sink and giving you optimal stopping power and resistance to fading.

Whether you have 4 or 6 piston calipers you need a rotor that's going to handle the abuse as well.

Jason

Audios S4

Well the B7 RS4 has 14.4" floating rotors. I have some friends that have Z06 Corvettes and they have a brake upgrade the 4 pad system to two pad. The B7 RS4 8 piston calipers have the same size pistons where as the Stage 4 Porsche Calipers from ECS (which I am seriously considering) have progressively smaller pistons from the leading pistons to tailing ones. I assume this is to address uneven pad ware. So because people running the Z06 change out the four pad system to a two pad, my question is what is the deal with 4 pad system, like the RS4 calipers, at the track? Is there uneven ware when these brakes are run hard?

ECS Tuning-Audi

You are 100% correct about the reasoning behind piston sizes.

I'm not sure about the technicalities behind changing from a 4 pad to a 2 pad caliper for z06 guys but our Stage 4 kit is a 6 piston caliper which is oriented to have smaller pistons at the leading end of the caliper and progressively larger pistons at the trailing end. As you said the reasoning for this is to address uneven pad ware. As the rotor spins counter clockwise the pad tends to want to rock towards the trailing end of the caliper so essentially there is going to be less of a load on the leading end of the pad so it makes sense to run a smaller piston in the leading piston since there would be less load there. The pad naturally wants to get sucked towards the rotation of the rotor so you want the most clamping force at the highest point of leverage to distribute the wear evenly.

I hope this makes sense.

Jason

dtykthqing

Is there uneven ware when these brakes are run hard?

dtykthqing

ECS Tuning-Audi

Not at all.

Jason