BC Racing ER Series 2-Way Coilover Kit – Mazda MX-5 Mk4 ND Roadster 2015 Onwards • N-34-ER

BC Racing N-34-ER ER Series 2-Way Coilover Kit

BC Racing ER Series coilover kit for Mazda MX-5 Mk4 ND Roadster 1.5 and 2.0 2015 onwards applications listed in the compatibility table.

The ER Series is BC Racing's two-way adjustable external-reservoir suspension range, designed for drivers who require greater control over suspension setup for demanding fast-road, track-day and motorsport use.

Compression and rebound damping can be adjusted independently, allowing each aspect of the damper response to be tuned separately. Compression provides 30 adjustment positions through the external reservoirs, while rebound provides a further 30 adjustment positions at the dampers.

The external reservoirs increase available damper oil capacity and help manage temperature during sustained hard use. Combined with monotube damper construction and ride-height adjustment independent from spring preload, the ER Series provides extensive scope for tailoring the suspension to the vehicle, tyres and intended use.

The current N-34-ER configuration uses 5 kg/mm front and 2.5 kg/mm rear springs, with external-reservoir dampers and pillowball upper mounts at both the front and rear.

• Product type: Complete 2-way adjustable coilover suspension kit
• Series: ER Series
• Primary use: Fast road, track day and motorsport
• Location / system: Front and rear suspension
• Brand: BC Racing
• Product reference / part number: N-34-ER
• Vehicle application: Mazda MX-5 / Miata Mk4 ND Roadster 2015 onwards
• Engine applications: 1.5 and 2.0 SKYACTIV-G petrol
• Damper design: Monotube
• Suspension design: True coilover front and rear
• External reservoirs: Front and rear
• Front spring rate: 5 kg/mm
• Rear spring rate: 2.5 kg/mm
• Damping adjustment: Independent 2-way compression and rebound adjustment
• Compression adjustment: 30 positions via the external reservoirs
• Rebound adjustment: 30 positions at the dampers
• Ride height adjustment: Adjustable independently from spring preload
• Front top mount: Pillowball
• Rear top mount: Pillowball
• Camber plates: Not applicable for this application
• Quantity supplied: Complete four-corner coilover suspension kit

Fitment advice: Designed for Mazda MX-5 Mk4 ND Roadster applications from 2015 onwards, including the applicable 1.5 and 2.0 SKYACTIV-G models listed in the compatibility table. The exact N-34-ER application data checked specifically identifies the Roadster; RF compatibility has therefore not been assumed. For imported, modified or previously repaired cars, matching the vehicle generation, chassis code, suspension layout and kit reference is recommended before ordering.

Other items to consider: When fitting or setting up this product, you may also want to consider purchasing replacement suspension fasteners, anti-roll bar links, suspension bushes and any worn suspension arms or ball joints. For a track-focused installation, professional four-wheel alignment and corner-weighting should also be considered once the final ride height has been established.

Useful tools / consumables: Suitable vehicle lifting equipment and axle stands, socket and spanner set, torque wrench, penetrating fluid, anti-seize compound and the appropriate BC Racing coilover adjustment tools. Professional wheel-alignment and suspension setup equipment will be required for final geometry and damper setup.

Difficulty guide: DIY Difficulty: Advanced. Installation involves replacement of the complete front and rear suspension assemblies together with installation and positioning of the external reservoir components. Ride height, geometry, compression and rebound damping must then be set correctly. Professional installation and setup are recommended for a suspension system of this type.

Why BC Racing? BC Racing ER Series suspension provides independently adjustable compression and rebound damping together with external reservoirs, giving considerably greater suspension tuning control than a conventional single-adjustable coilover. The combination of monotube dampers, increased oil capacity, independent ride-height adjustment and separate 30-position compression and rebound adjustment makes the ER Series particularly well suited to serious fast-road, track-day and motorsport applications.

What’s in the box: Complete four-corner BC Racing ER Series coilover suspension kit with front and rear dampers, 5 kg/mm front springs, 2.5 kg/mm rear springs, front and rear external reservoir assemblies, pillowball upper mounts, coilover adjustment tools and associated installation components supplied with the N-34-ER kit.

Installation / setup notes: The external reservoirs must be positioned and secured correctly during installation. Ride height, spring preload, compression damping and rebound damping should be set methodically, beginning from a known baseline and making controlled adjustments. Once the required ride height has been established, all suspension mounting hardware should be tightened to the appropriate specification and a full four-wheel geometry alignment carried out before final suspension tuning.