Product Details
BC Racing HM Series Coilovers for the 2000-2006 BMW 3 Series Convertible M3 (E46 M3) combine the inverted-damper durability of the RM Series with the independent compression and rebound tuning of the ER Series — BC's pick for track-day McPherson-strut builds. Every kit is extensively tested on the 3 Series Convertible M3 chassis and refined until it balances ride quality with performance — the reason 3 Series Convertible M3 coilovers from BC Racing are the best-selling adjustable kits in their segment worldwide.
HM Series kits use an inverted mono-tube damper on McPherson-strut chassis (upright on double-wishbone) with external reservoirs feeding separate compression and rebound adjusters. The result: the tuning depth of the ER Series inside the heavy-load chassis architecture of the RM. 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 3 Series Convertible M3 coilovers arrive tuned for the 3 Series Convertible M3 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)
- Inverted mono-tube damper on McPherson-strut vehicles; upright on double-wishbone
- Combines RM Series inverted-damper architecture with ER Series 2-way adjustability
- 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-121-HM |
| Part Name | HM Series Coilovers |
| Vehicle | 2000-2006 BMW 3 Series Convertible M3 RWD (E46 M3) |
| Drivetrain | RWD |
| Chassis Code | E46 M3 |
| Damping Adjustment | 2-Way (30 levels rebound 30 levels compression) |
| Ride-Height Adjustable | Yes |
| Spring Rate - Front | 6 kg/mm |
| Spring Rate - Rear | 8 kg/mm |
| Spring Size - Front | 62-180-6K |
| Spring Size - Rear | 62-150-8K |
| Swift Springs - Front | 62-178-X |
| Swift Springs - Rear | 62-152-X |
| Camber Plates - Front | Included |
| Camber Plates - Rear | Not Applicable |
| Suspension Design - Front | True Coilover |
| Suspension Design - Rear | True Coilover |
| Notes | The HM Series is not available in Extreme-Low configuration. |
Vehicle Fitment
- 2000 BMW 3 Series Convertible M3 RWD (E46 M3)
- 2001 BMW 3 Series Convertible M3 RWD (E46 M3)
- 2002 BMW 3 Series Convertible M3 RWD (E46 M3)
- 2003 BMW 3 Series Convertible M3 RWD (E46 M3)
- 2004 BMW 3 Series Convertible M3 RWD (E46 M3)
- 2005 BMW 3 Series Convertible M3 RWD (E46 M3)
- 2006 BMW 3 Series Convertible M3 RWD (E46 M3)