Product Details
BC Racing ER Series Coilovers for the 2003-2005 Honda Civic Si (EP3) 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 Civic Si EP3 chassis and refined until it balances ride quality with performance — the reason Civic Si 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's reputation in the aftermarket suspension world is built on four things: competitive pricing that beats the rest of the fully-adjustable market, customization depth that rivals the top-tier race brands, long-term reliability earned over 20 years of production, and a rebuildable design that keeps the same set of dampers serving you through multiple builds. These Civic Si coilovers arrive tuned for the EP3 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 | A-06-ER |
| Part Name | ER Series Coilovers |
| Vehicle | 2003-2005 Honda Civic Si FWD (EP3) |
| Drivetrain | FWD |
| Chassis Code | EP3 |
| Damping Adjustment | 2-Way (30 levels rebound 30 levels compression) |
| Ride-Height Adjustable | Yes |
| Spring Rate - Front | 6.5 kg/mm |
| Spring Rate - Rear | 12 kg/mm |
| Spring Size - Front | 62-180-6.5K |
| Spring Size - Rear | 62-130-12K |
| Swift Springs - Front | 62-178-X |
| Swift Springs - Rear | 62-127-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
- 2003 Honda Civic Si FWD (EP3)
- 2004 Honda Civic Si FWD (EP3)
- 2005 Honda Civic Si FWD (EP3)