Product Details
These BC Racing RM Series coilovers fit the 2004-2005 BMW 645Ci RWD (E63/E64). They are purpose-built for McPherson-strut cars that see serious track time, with an inverted mono-tube damper engineered to outlast a hard season of lateral loads. Every kit is developed specifically for the BMW E63/E64 645Ci and refined to balance ride quality with performance, which is why BC coilovers are the best-selling adjustable kits in their segment worldwide.
The RM Series inverts the mono-tube damper on strut-equipped chassis, putting the heavy internals where the lateral loads are worst. A wider piston shaft than conventional uprights means more consistent damping on long sessions and more fatigue life before rebuild. 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 BC Racing E63/E64 645Ci coilovers arrive ready to bolt in, with no break-in period and 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 simultaneous compression/rebound damping adjuster
- Inverted mono-tube damper (front) with oversized 46 mm piston shaft
- Handles higher lateral loads on McPherson-strut applications
- 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-52-RM |
| Part Name | RM Series Coilovers |
| Vehicle | 2004-2005 BMW 645Ci |
| Drivetrain | RWD |
| Chassis Code | E63/E64 |
| Damping Adjustment | 1-Way (30 levels) |
| Ride-Height Adjustable | Yes |
| Spring Rate - Front | 7 kg/mm |
| Spring Rate - Rear | 4.5 kg/mm |
| Spring Size - Front | 62-180-7 |
| Spring Size - Rear | 62-220-4.5 |
| Swift Springs - Front | 62-152-X |
| Swift Springs - Rear | 62-203-X |
| Top Mounts - Front | Camber Plates |
| Top Mounts - Rear | Reuses OEM Mounts |
| Rear Damping Extenders | Not Compatible |
| Suspension Design - Front | True Coilover |
| Suspension Design - Rear | True Coilover |
| Notes |
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