Maruha Motors BC Street Coilover Suspension
Mazda Miata / MX-5 NA & NB (1990–2005)
 
Developed specifically for the NA and NB Mazda Miata, the Maruha Motors BC Street Coilover Kit delivers the balanced handling and ride quality these lightweight roadsters deserve.
 
Unlike many generic coilovers, this system addresses a well-known limitation of the NA/NB chassis — reduced rear suspension stroke when the car is lowered. Maruha solves this with their 20mm extended rear upper mounts, restoring valuable shock travel and dramatically improving composure over uneven roads.
 
With 6kg/mm front and 4kg/mm rear springs, 15-way adjustable damping, and full ride height adjustment, the BC Street kit is tuned for responsive street performance without sacrificing daily comfort.
 
Manufactured in small batches in Japan, this suspension reflects Maruha Motors’ long-standing reputation for building thoughtfully engineered performance parts specifically for the Miata platform.
 
Designed for Real Street Driving
Maruha approached this suspension system with a street-first philosophy. Through extensive testing, they developed custom spring specifications and damping settings that maximize grip and driver feedback while preserving comfort for daily driving.
 
The 15-stage adjustable damping system allows drivers to fine-tune suspension response for different road conditions, weather, and driving styles.
 
Thanks to a full-length height adjustment system, ride height can be adjusted without sacrificing suspension stroke, ensuring proper damper performance at any height setting.
 
Built with Long-Term Service in Mind
Unlike many coilover kits that are treated as disposable, the Maruha BC Street system is designed to be fully serviceable. The dampers can be overhauled and refreshed, allowing owners to maintain peak suspension performance for years to come.
 
Each kit is custom-produced in Japan, ensuring strict quality control and the performance standards expected from Maruha Motors.
 
Key Features
Height adjustable coilover suspension
Full-length ride height adjustment for optimal stroke retention
Custom spring rates: 6kg/mm front / 4kg/mm rear
15-way adjustable damping with billet adjustment knobs
20mm high-stroke rear upper mount to increase suspension travel
NB OEM-style upper mounts for improved comfort and durability
Dedicated aluminum upper spring seat for stable spring positioning
Rust-resistant plated damper bodies
Fully rebuildable / overhaul capable
100% made in Japan
Small batch production for consistent quality
 
Vehicle Fitment
Mazda Miata / MX-5 NA & NB
Model Years 1990–2005