Product Details
BC Racing ER Series Coilovers for the 2015-2020 BMW 4 Series (F32) put race-grade adjustability in reach of the serious track-day driver, with independent compression and rebound tuning at every corner. Every kit is extensively tested on the F32 chassis and refined until it balances ride quality with performance — the reason 4 Series coilovers from BC Racing are the best-selling adjustable kits in their segment worldwide.
ER Series kits run a linear twin-piston design in a mono-tube body, with compression and rebound on separate external adjusters. That lets you fine-tune chassis balance corner by corner — stiffer front for turn-in, softer rear for exit grip, whatever the session calls for. Where BC Racing separates itself is tuning philosophy: every off-the-shelf spring rate and damper setup is chosen to stay comfortable on daily roads while still delivering real performance at the track. If you want something different, Swift Springs, custom rates, and custom valving are all options at checkout — BC will match the valving of the dampers to whatever springs you pick, something most brands don't offer outside their flagship race lineup.
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 4 Series coilovers arrive tuned for the F32 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 (top of damper)
- 30-level compression adjustment (external reservoir)
- 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 | I-84-ER |
| Part Name | ER Series Coilovers |
| Vehicle | 2015-2020 BMW 4 Series |
| Drivetrain | RWD |
| Chassis Code | F32 |
| Damping Adjustment | 2-Way (30 levels rebound/30 levels compression) |
| Ride-Height Adjustable | Yes |
| Spring Rate - Front | 5.5 kg/mm |
| Spring Rate - Rear | 9 kg/mm |
| Spring Size - Front | 62-190-5.5K |
| Spring Size - Rear | 62-220-9K |
| Swift Springs - Front | 62-178-X |
| Swift Springs - Rear | 62-228-X |
| Camber Plates - Front | Included |
| Camber Plates - Rear | Not Applicable |
| Suspension Design - Front | True Coilover |
| Suspension Design - Rear | True Coilover |
| Notes |
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Vehicle Fitment
- 2015 BMW 4 Series RWD (F32)
- 2016 BMW 4 Series RWD (F32)
- 2017 BMW 4 Series RWD (F32)
- 2018 BMW 4 Series RWD (F32)
- 2019 BMW 4 Series RWD (F32)
- 2020 BMW 4 Series RWD (F32)