2016-2024 Audi A4 / S4 / RS4 (B9) CCB Big Brake Kit | Akebono 9N 6-Piston
Official Warranty: 1‑year free replacement for quality defects or coating issues under normal (non-track) use.
2016-2024 Audi A4 / S4 / RS4 (B9) CCB Big Brake Kit — Genuine Akebono OEM Audi RS 6-Piston (9N) Caliper Front + TTSPORT EP4 4-Piston Caliper with EPB Rear Setup
B9 A4, S4, and RS4 owners usually arrive here because the factory iron brake package adds dust, heat saturation, and front-end mass when the car is driven hard on mountain roads, high-speed street use, or track days. This StopFlex kit pairs a 400mm front carbon-ceramic rotor with the Genuine Akebono OEM Audi RS 6-Piston (9N) Caliper, then matches the rear with a TTSPORT EP4 4-Piston Caliper with EPB on a 380mm carbon-ceramic rotor. The result is higher front thermal capacity, lower rotating and unsprung mass than an iron rotor package, cleaner open-wheel appearance, and trim-confirmed fitment rather than a generic B9 assumption.
- 400mm front carbon-ceramic rotors require 20-inch or larger wheels on this B9 A4 / S4 / RS4 kit; wheel spoke clearance is still checked against the Genuine Akebono OEM Audi RS 6-Piston (9N) Caliper before build.
- Rear braking is upgraded with a 380mm carbon-ceramic rotor and TTSPORT EP4 4-Piston Caliper with EPB, preserving the electronic parking-brake function used on B9 Audi models.
- Every kit is engineered to the confirmed A4, S4, or RS4 trim because B9 variants can differ in upright, hub, brake PR-code, and wheel-offset clearance details.
Fitment Hard Lines
| Field | Specification |
|---|---|
| Vehicle | Audi A4 / S4 / RS4 (B9) |
| Model years | 2016-2024 |
| Front setup | Genuine Akebono OEM Audi RS 6-Piston (9N) Caliper / 400mm |
| Rear setup | TTSPORT EP4 4-Piston Caliper with EPB / 380mm |
| Page type | Complete CCB kit upgrade |
| Minimum wheel size | 20" (for the 400 mm front rotor) |
Every StopFlex kit is bespoke-engineered for your exact model and trim — the brackets, rotor-hat offsets, and caliper mounting are matched to your specific car, not assumed from the platform. This matters because trims that share a chassis name can differ mechanically: a pure M or performance variant often carries different front knuckles/uprights, hub geometry, and wheel axial (ET) clearance than the standard models in the same family, so a bracket and hat offset that bolt onto one are not the same parts that fit the other. StopFlex supplies the calipers, pads, rotor hats, floating hardware, and brake lines as a matched system built to your confirmed trim. Cars with modified knuckles, modified uprights, or non-factory suspension mounting points must be reviewed before ordering and are not treated as direct-fit.
This setup uses a 400 mm front rotor, so the minimum wheel size is 20". Wheels under 20" will not clear the caliper and rotor, and spoke profile and offset affect clearance too — confirm your exact wheels before ordering.
| Wheel Size (Standard) | Disc Range |
|---|---|
| 15" | 260 mm – 285 mm |
| 16" | 285 mm – 300 mm |
| 17" | 300 mm – 330 mm |
| 18" | 330 mm – 355 mm |
| 19" | 355 mm – 380 mm |
| 20" | 380 mm – 400 mm |
| 21" | 400 mm – 420 mm |
| 22" | 420 mm – 440 mm |
Caliper Overview — Front & Rear Balance
Front Caliper (Primary Upgrade)
The front axle uses the Genuine Akebono OEM Audi RS 6-Piston (9N) Caliper, giving the B9 chassis a six-piston fixed-caliper layout for more even pad loading and firmer pedal response than a smaller sliding-caliper iron setup. Its OEM Audi RS provenance matters because the caliper is based on a production performance application, not an anonymous universal casting. StopFlex matches this caliper to a 400mm carbon-ceramic rotor, trim-specific bracket geometry, and the correct hat offset for the buyer’s exact A4, S4, or RS4 configuration.
Rear Caliper (Balance)
The rear axle uses the TTSPORT EP4 4-Piston Caliper with EPB on a 380mm carbon-ceramic rotor, adding real rear thermal capacity instead of leaving the rear axle as an afterthought. The EP4 uses four hydraulic service pistons plus a dedicated EPB actuator piston, so the car keeps factory electronic parking-brake convenience while the rear brake package is sized to work with the 400mm front system.
Front & rear, engineered together: This kit is engineered as a front-and-rear system so the 400mm Akebono front package and 380mm EP4 rear package share the work instead of creating a front-heavy brake conversion. Matching rotor diameter, piston area, hat offset, brackets, pads, lines, and hardware to the exact B9 trim helps maintain stable brake bias, predictable ABS behavior, and consistent pedal feel.
Make It Yours — Color & Logo Customization
Every StopFlex kit-upgrade order can be finished with custom caliper colors, a custom caliper logo, and custom rotor hat colors, so the brake package matches your exact build instead of a fixed off-the-shelf look.
- Custom caliper color
- Custom caliper logo
- Custom rotor hat color
Why StopFlex CCB
Lower Unsprung Mass
StopFlex carbon-ceramic rotors are engineered to reduce rotor mass versus comparable iron discs, helping the suspension react cleaner and the steering feel more precise.
High-Temperature Stability
The carbon-silicon-carbide matrix is built for stable braking behavior at temperatures that can push iron rotors into heavy fade.
Rust-Free Rotor Surface
Carbon ceramic does not form orange flash rust after rain, washing, or storage, keeping the visible rotor face cleaner behind open wheels.
Long Street-Service Potential
In normal road use with matched pads and proper bedding, StopFlex CCB rotors are designed for far longer service life than typical iron replacement rotors.
Low Visible Dust
When paired with matched StopFlex pads, the system produces very low visible brake dust compared with conventional iron rotor and pad combinations.
Premium Ceramic-Glaze Appearance
StopFlex's proprietary coating creates a bright, high-end ceramic-glaze finish with subtle glaze texture and a more premium visual character behind open wheels.
Street-Usable Cold Bite
Street Spec and Track-Day Spec rotors are designed for normal first-stop road use, including cold-weather operation. Motorsport Spec is the competition-focused exception.
Continuous Fiber Reinforcement
Long-fiber carbon ceramic construction improves structural strength and thermal durability versus chopped-fiber approaches.
Heat Management Note
Carbon ceramic rotors tolerate extreme surface temperature, but they do not remove every heat-management requirement. During repeated hard stops, heat can still soak into pads, fluid, seals, calipers, wheels, and nearby components. For long track sessions, mountain descents, or sustained aggressive driving, brake cooling and high-temperature fluid are still recommended.
Street / Track-Day / Motorsport Rotor Options
Street Spec
Ceramic coating, cross-drilled face, and large cooling channels.
Best for daily driving and premium street builds that need clean cold bite, low dust, corrosion-free appearance, and long service life.
Track-Day Spec
Ceramic coating, blank face, and honeycomb cooling channels.
Best for fast-road and track-day use where repeated braking stability matters more than maximum visual drilling style.
Motorsport Spec
Uncoated blank face with honeycomb cooling channels.
Best for race-focused builds that run competition pads, high-temperature fluid, cooling strategy, and a proper warm-up window. Not the default street choice.
Package Scope
| Item | Details |
|---|---|
| Front calipers | Genuine Akebono OEM Audi RS 6-Piston (9N) Caliper |
| Front CCB rotors | 400mm |
| Rear calipers | TTSPORT EP4 4-Piston Caliper with EPB |
| Rear CCB rotors | 380mm |
| CCB brake pads | Matched for the supplied StopFlex carbon ceramic rotors |
| Rotor hats and floating hardware | Vehicle-specific hardware package |
| Brake lines | Included for complete kit-upgrade orders |
| Color customization | Custom caliper colors, a custom caliper logo, and custom rotor hat colors are available for every kit-upgrade order. |
| Order scope | Default listing is full-car set when front and rear are specified. Front-only or rear-only orders can be arranged after confirmation. |
EPB & Rear Caliper Options
This vehicle leaves the factory with an electronic parking brake (EPB) built into the rear brake, so the rear of the kit is built to keep that EPB working. There are two rear paths. The first is a dual-caliper rear: a main performance caliper handles braking while a dedicated EPB actuator caliper is retained alongside it, so the electronic parking brake, auto-hold, and hill-start assist all keep working; on this path the rear performance caliper can be the TTSPORT EP4 / EP4S 4-piston caliper. The second is an EPB-integrated caliper, a single rear caliper with the electromechanical parking-brake motor built in for a cleaner install with fewer parts behind the wheel; on this path the rear is the TTSPORT EP4 / EP4S 4-piston caliper with integrated EPB. Which path fits best depends on your exact trim and EPB configuration, your budget, your appearance preference, and your wheel size and spoke clearance. Confirm your car's rear-brake configuration with StopFlex before ordering so the correct EPB-compatible rear option is built for your kit.
| Rear option | What it is | Rear caliper | Best when |
|---|---|---|---|
| Dual caliper (EPB retained) | Performance caliper plus a dedicated EPB actuator caliper, both fitted on the rear, so the factory electronic parking brake keeps working. | TTSPORT EP4 / EP4S 4-Piston Caliper | You want guaranteed factory EPB, auto-hold, and hill-start behavior preserved. |
| EPB-integrated caliper | A single rear caliper with the electromechanical parking-brake motor built in, for a cleaner install with fewer parts behind the wheel. | TTSPORT EP4 / EP4S 4-Piston Caliper with integrated EPB | You want a cleaner single-caliper rear with full EPB function. |
TTSPORT EP4S rear caliper specification (the EP4 shares the same engineering, slightly more compact):
| Specification | EP4S |
|---|---|
| Axle position | Rear |
| Piston count | 4 hydraulic + 1 EPB actuator |
| Piston type | Two-piece heat-insulated, dust boots + EPB actuator |
| Piston diameter | 28 mm × 4 / 27 mm × 1 |
| Total piston area | 30.4 cm² per caliper |
| Manufacturing process | Two-piece forged aluminum body |
| Net weight | 4.50 kg per caliper (no pads) |
| Surface finish | High-temperature gloss coating |
| Recommended wheel size | 18 in or larger |
FAQ
Will this kit fit every 2016-2024 Audi A4, S4, and RS4 B9 the same way?
No. StopFlex does not treat the B9 chassis name as a universal fitment. Brackets, rotor-hat offsets, caliper mounting, and wheel-clearance checks are built around the confirmed A4, S4, or RS4 trim, brake PR code, hub/upright geometry, and wheel package.
What wheel size do I need for the 400mm front rotor?
The 400mm front carbon-ceramic rotor requires 20-inch or larger wheels. Wheel diameter alone is not enough; spoke profile, offset, and barrel shape must also clear the Genuine Akebono OEM Audi RS 6-Piston (9N) Caliper.
Will my electronic parking brake still work?
Yes, this kit uses the TTSPORT EP4 4-Piston Caliper with EPB at the rear. It has four hydraulic service pistons for braking and a dedicated EPB actuator piston, so the B9 retains electronic parking-brake operation while gaining a 380mm rear carbon-ceramic rotor.
Why move from factory iron brakes to this carbon-ceramic kit on a B9 Audi?
Carbon-ceramic rotors reduce brake dust and rotating mass while increasing heat capacity for repeated high-speed stops. On a B9 A4, S4, or RS4 with open wheels or aggressive driving use, the payoff is cleaner wheels, less front-end weight, and better resistance to heat-related fade than a comparable iron rotor package.
Need Fitment Confirmation?
Send the exact vehicle details, current rotor sizes, and caliper type before ordering.
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