Product Details
BC Racing ER Series Coilovers for the 2001-2006 BMW M3 (E46) 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 E46 chassis and refined until it balances ride quality with performance — the reason M3 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. The off-the-shelf setup from BC Racing is deliberately balanced — spring rates and valving chosen so the kit feels comfortable day-to-day without giving up performance when you push it. Drivers who want a different recipe can spec Swift Springs, custom spring rates, or fully custom valving at checkout; BC will tune the dampers to match, which is a depth of customization most brands only offer on their top-tier kits.
BC Racing has been manufacturing adjustable coilovers since 2004 and is one of the most popular coilover brands in the automotive tuning industry for a reason: competitive pricing, deep customization, proven reliability, and a fully rebuildable damper design that lasts years instead of seasons. These M3 coilovers arrive tuned for the E46 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-14-ER |
| Part Name | ER Series Coilovers |
| Vehicle | 2001-2006 BMW M3 |
| Drivetrain | RWD |
| Chassis Code | E46 |
| Damping Adjustment | 2-Way (30 levels rebound/30 levels compression) |
| Ride-Height Adjustable | Yes |
| Spring Rate - Front | 6 kg/mm |
| Spring Rate - Rear | 9 kg/mm |
| Spring Size - Front | 62-180-6K |
| Spring Size - Rear | 62-145-9K |
| Swift Springs - Front | 62-178-X |
| Swift Springs - Rear | 62-140-X |
| Camber Plates - Front | Included |
| Camber Plates - Rear | Not Applicable |
| Suspension Design - Front | True Coilover |
| Suspension Design - Rear | Divorced |
| Notes | The ER Series is not available in Extreme-Low configuration. |
Vehicle Fitment
- 2001 BMW M3 RWD (E46)
- 2002 BMW M3 RWD (E46)
- 2003 BMW M3 RWD (E46)
- 2004 BMW M3 RWD (E46)
- 2005 BMW M3 RWD (E46)
- 2006 BMW M3 RWD (E46)