Product Details
BC Racing ER Series Coilovers for the 1990-2005 Mazda Miata/MX-5 (NA8C/NB8C) 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 Miata/MX-5 chassis and refined until it balances ride quality with performance — the reason Miata/MX-5 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.
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 Miata/MX-5 coilovers arrive tuned for the Miata/MX-5 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 | N-04-ER |
| Part Name | ER Series Coilovers |
| Vehicle | 1990-2005 Mazda Miata/MX-5 RWD (NA8C/NB8C) |
| Drivetrain | RWD |
| Chassis Code | NA8C/NB8C |
| Damping Adjustment | 2-Way (30 levels rebound 30 levels compression) |
| Ride-Height Adjustable | Yes |
| Spring Rate - Front | 8 kg/mm |
| Spring Rate - Rear | 6 kg/mm |
| Spring Size - Front | 62-180-8K |
| Spring Size - Rear | 62-150-6K |
| Swift Springs - Front | 62-178-X |
| Swift Springs - Rear | 62-152-X |
| Camber Plates - Front | Not Applicable |
| Camber Plates - Rear | Not Applicable |
| Suspension Design - Front | True Coilover |
| Suspension Design - Rear | True Coilover |
| Notes | The ER Series is not available in Extreme-Low configuration. |
Vehicle Fitment
- 1990 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 1991 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 1992 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 1993 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 1994 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 1995 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 1996 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 1997 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 1998 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 1999 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 2000 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 2001 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 2002 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 2003 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 2004 Mazda Miata/MX-5 RWD (NA8C/NB8C)
- 2005 Mazda Miata/MX-5 RWD (NA8C/NB8C)