Product Details
BC Racing ZX Series Coilovers for the 2017+ Audi A4/S4 (B9) bring the same three-axis adjustability as the race-spec ZR Series with valving tuned for drivers who split time between street and track. Every kit is extensively tested on the B9 chassis and refined until it balances ride quality with performance — the reason A4/S4 coilovers from BC Racing are the best-selling adjustable kits in their segment worldwide.
ZX Series kits share the three-axis damper architecture of the race-spec ZR Series, tuned out of the box for drivers who want race-grade adjustability without the ride harshness on the commute home. BC Racing takes pride in choosing spring rates and damper valving that balance comfort and performance — you never end up with the oversprung, harsh-riding kit some brands ship as their only option. Drivers who want to deviate from the factory setup can order Swift Springs, custom spring rates, and custom valving at checkout; BC will re-valve the dampers to match whatever you specify, a level of customization most brands reserve for their top-tier race kits.
Since 2004, BC Racing has grown into one of the most trusted names in aftermarket coilovers — not by racing to the bottom on price, but by pairing that price with real build quality, deep customization options, and a damper design any suspension shop can rebuild instead of replacing. These A4/S4 coilovers arrive tuned for the B9 chassis and ready to bolt in — no break-in period, no guessing at setup. Every kit ships with a 2-year manufacturer warranty, lifetime access to BC service parts (pistons, seals, shafts — no unit replacement required when it's time for a rebuild), and in-house tech support from both BC Racing and the Springrates team.
Features
- 30-level rebound adjustment
- 15-level low-speed compression adjustment
- 12-level high-speed compression adjustment
- Inverted mono-tube damper with linear twin-piston design
- Ride height adjustable independent of spring preload
- Upper mount hardware varies by chassis — camber plates, pillowball, or reused OEM mounts. See the Specifications table for what's included on your kit.
- Swift Spring and custom spring rate upgrades available at checkout
- Custom damper valving paired with custom spring rates on request
- Fully rebuildable — replacement parts available from BC for the life of the shock
- 2-year manufacturer warranty against defects
Specifications
| Part Number | S-27-ZX |
| Part Name | ZX Series Coilovers |
| Vehicle | 2017+ Audi A4/S4 |
| Drivetrain | FWD/AWD |
| Chassis Code | B9 |
| Damping Adjustment | 3-Way (30 levels rebound/15 LSC/12 HSC) |
| Ride-Height Adjustable | Yes |
| Spring Rate - Front | 10 kg/mm |
| Spring Rate - Rear | 8 kg/mm |
| Spring Size - Front | 62-220-10K |
| Spring Size - Rear | 62-190-8K |
| Swift Springs - Front | 62-203-X |
| Swift Springs - Rear | 62-178-X |
| Camber Plates - Front | Not Applicable |
| Camber Plates - Rear | Not Applicable |
| Suspension Design - Front | True Coilover |
| Suspension Design - Rear | True Coilover |
| Notes |
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Vehicle Fitment
- 2017 Audi A4/S4 FWD/AWD (B9)
- 2018 Audi A4/S4 FWD/AWD (B9)
- 2019 Audi A4/S4 FWD/AWD (B9)
- 2020 Audi A4/S4 FWD/AWD (B9)
- 2021 Audi A4/S4 FWD/AWD (B9)
- 2022 Audi A4/S4 FWD/AWD (B9)
- 2023 Audi A4/S4 FWD/AWD (B9)
- 2024 Audi A4/S4 FWD/AWD (B9)
- 2025 Audi A4/S4 FWD/AWD (B9)
- 2026 Audi A4/S4 FWD/AWD (B9)