The build and parts list
| Vehicle | Audi S4 (B9) |
|---|---|
| Front caliper | Factory Akebono 6-piston fixed caliper (retained) |
| Front rotor | STOPFLEX carbon ceramic, 380 x 34 mm |
| Pads | STOPFLEX low-dust ceramic compound |
| Wheel context | Clears factory 19-inch S4 wheels |
| Scope | Front-axle rotor conversion using the stock front calipers |
Confirm before you order
This kit is built for the Audi S4 B9 running the factory Akebono 6-piston fixed front calipers. Verify your caliper type first, since that hardware is what the rotor is sized around.
What the upgrade actually does
| STOPFLEX feature | Why it matters on the S4 B9 | What you notice |
|---|---|---|
| Carbon ceramic rotor, ~half the weight of steel | The S4 is nose-heavy and front-biased, so cutting mass at the front wheel matters more here than at the rear. | Front suspension settles quicker over rough pavement and the nose feels lighter on turn-in. |
| Carbon ceramic friction surface | The factory Akebono caliper is plenty strong; what limits confidence is iron-rotor heat soak after repeated hard stops. | Pedal stays consistent down a long grade or after back-to-back stops instead of going soft. |
| Low-dust ceramic pads | S4 owners know the black-dust cycle: wash the wheels, drive a few miles, watch it come right back. | Wheels stay clean far longer, so you clean them less and the car looks better between washes. |
| Rotors that don't rust | Iron discs flash-rust after rain or a wash, which looks rough through open spokes. | No orange film on the rotor face after wet driving or sitting overnight. |
| Long-fiber CCB construction | Daily-driven S4s rack up miles, so rotor durability changes your maintenance math. | Street life can reach about 250,000 to 300,000 km when the car stays off track. |
What gets better
- Less unsprung weight at the front axle, where the S4 needs it most
- More consistent pedal under repeated hard braking and long descents
- Much lower brake dust with the matched STOPFLEX pads
- No rotor rust after rain or washing
- Long street service life with no track use
What to confirm first
- Your front calipers are the factory Akebono 6-piston fixed units
- Your wheels are the factory 19-inch S4 fitment or clear a 380 mm rotor
- This is a front-axle conversion, not a full four-corner kit
- Your goal is street feel, cleaner wheels, and heat stability rather than a track-only build
If you're not sure your car matches the spec shown here, send us your details and we'll confirm Audi S4 B9 fitment before you order through our Audi CCB collection.
Build gallery
Audi S4 B9 CCB FAQ
Does this STOPFLEX kit keep the factory Audi S4 B9 Akebono calipers?
Yes. This is a front rotor-only conversion built for the Audi S4 B9 with the factory Akebono 6-piston fixed front calipers. You keep the original calipers and swap the rotors and pads.
Why upgrade only the front axle on the S4 B9?
The S4 carries a front-biased layout, so the front brakes take most of the heat and load. Targeting the front axle puts the carbon ceramic rotor where the demand is highest, which is where you feel the gain in fade resistance and pedal consistency.
Will the 380 mm front rotor clear factory 19-inch S4 wheels?
Yes. The 380 mm front rotor is sized to fit within factory 19-inch Audi S4 wheel barrels.
How do these carbon ceramic brakes handle rain?
With the matching STOPFLEX pad compound, wet braking stays predictable. The rotors also do not rust after rain or washing, so you avoid the surface corrosion common with iron discs.
How long do STOPFLEX rotors last on a street-driven S4?
For street use with no track work, STOPFLEX states rotor life can reach about 250,000 to 300,000 km. Real-world life depends on your driving style, pad choice, and conditions.
