Vehicle & brake configuration
| Vehicle | Audi RS4 (B9) |
|---|---|
| Front calipers | Factory Akebono 6-piston fixed calipers, retained |
| Front rotors | STOPFLEX carbon ceramic, 400 x 38 mm |
| Pads | STOPFLEX low-dust compound |
| Wheels fitted | Factory 20-inch RS4 wheels |
| Upgrade scope | Front-axle rotor & pad upgrade, factory calipers kept |
Confirm before you order
This is a front-axle upgrade for cars on the factory Akebono 6-piston front calipers, not a blanket fit for every RS4 or every wheel. Check your existing calipers, current front rotor size, and actual wheel-barrel clearance before buying.
What the upgrade changes
| STOPFLEX feature | Why it matters on the RS4 B9 | What you notice |
|---|---|---|
| Carbon ceramic rotor, about half the weight of the same-size steel rotor | The B9 is nose-heavy and front-biased, so cutting weight at the front rotor takes load off the busiest, heaviest corner of the car. | Lighter steering, a front end that settles quicker over rough pavement and in fast direction changes. |
| High-heat friction stability (around 0.3μ at 900°C) | A heavy, quick wagon dumps a lot of energy into the front brakes on a back-road run or a long downhill grade. | Pedal feel that holds up when you stack several hard stops together instead of going soft. |
| Very low dust with STOPFLEX pads | Factory RS steel brakes are famous for coating the wheels in black dust within a few drives. | Cleaner wheel faces and a lot less time at the wash bucket, which shows on dark RS finishes. |
| No rust after rain, normal cold bite to around -20°C | A daily-driven RS4 sees wet commutes, car washes, and cold mornings year-round. | No flash-rust film after a wash, and a normal first stop on a freezing morning. |
| Long-fiber CCB construction, roughly 250,000–300,000 km street life | Owners who keep an RS4 long-term want a brake that lasts, not a track consumable. | A rotor that stays in service for years of street use instead of regular replacement. |
What gets better
- Lower front unsprung mass for sharper turn-in and a calmer ride over bumps
- More consistent pedal under repeated hard braking and long descents
- Far less brake dust on the front wheels
- No surface rust after wet weather or a wash
- Long street service life without track abuse
What to confirm first
- Your car runs the factory Akebono 6-piston fixed front calipers
- Current front rotor size matches the 400 mm package
- Factory 20-inch wheel barrel clears the rotor and caliper
- This is a front-axle upgrade; calipers are reused, not replaced
If you're not sure your car matches the spec shown here, send us your details and we'll confirm Audi RS4 B9 fitment before you order through our Audi CCB collection.
Build gallery
RS4 B9 carbon ceramic FAQ
Why does a front-only carbon ceramic upgrade make sense on the RS4 B9?
The RS4 B9 is nose-heavy and front-biased, so the front axle does most of the braking work and carries the most unsprung weight. Upgrading the front rotors targets exactly where the heat builds and where weight hurts handling most, which is why a front-axle change is felt the quickest.
What factory setup does this upgrade fit?
It is built for the Audi RS4 B9 running the factory Akebono 6-piston fixed front calipers with the standard steel front package. You keep your existing calipers and swap to a STOPFLEX 400mm carbon ceramic rotor and matching pad. Confirm your calipers, current rotor size, and wheel clearance before ordering.
Do I have to replace the calipers too?
No. This is a rotor-and-pad upgrade that reuses the factory Akebono front calipers. That keeps the job focused on the parts you actually feel, instead of a full front-brake conversion.
Is it fine for daily driving and cold weather?
Yes. STOPFLEX carbon ceramic rotors work in normal street conditions, brake normally on the first stop even around -20°C, and do not rust after rain or a wash. Paired with STOPFLEX pads they throw very little dust, which shows on dark RS wheels.
Will the 400mm rotors clear the factory 20-inch RS4 wheels?
This setup is built around a 400mm front rotor and is presented as compatible with factory 20-inch RS4 wheels. Wheel barrel shape varies by design and market, so confirm clearance before you buy.
How long do the rotors last on the street?
For street use off the track, STOPFLEX puts rotor life at roughly 250,000 to 300,000 km. Real-world life depends on how you drive, your pad choice, and the car's condition.
