BC Racing coilovers are a popular choice among automotive enthusiasts for their balance of performance, adjustability, and reliability. Whether you're tuning a BMW, Nissan 370Z, or other supported models, BC Racing provides coilover kits that allow for customization of ride height, spring rates, and damping. However, the installation process can be complex, and users often seek detailed guidance to ensure proper setup and avoid common pitfalls. This guide compiles key installation information, technical specifications, and user considerations from verified sources to help users make informed decisions and execute installations correctly.
Overview of BC Racing Coilover Kits
BC Racing offers a range of coilover kits designed to accommodate different vehicle platforms and performance goals. The standard kits are engineered to provide a moderate drop—typically around 1 inch below OEM ride height at maximum height—and are tuned for a balance between street comfort and track performance. The extreme drop variant offers greater lowering capability, approximately 2 inches below OEM at maximum height, and includes stiffer spring rates in some configurations. These kits are designed with a broad adjustment range, allowing users to fine-tune their vehicle’s suspension to suit specific driving conditions or aesthetic preferences.
Coilover kits include four units, one for each corner of the vehicle. However, some models may not include top mounts, necessitating the use of original equipment manufacturer (OEM) components. For certain applications, such as E30, Q45, or 240Z platforms, additional welding may be required at the lower mount, which must be performed by a professional.
Technical Specifications and Adjustability
The adjustability of BC Racing coilovers is one of their most appealing features. Users can adjust the spring preload and damping settings independently, allowing for customization based on driving conditions or preferences. The spring rates in standard kits are approximately 15–20% stiffer than OEM specifications, and damping valving is 20–30% stiffer. These values are designed to accommodate the lowering capability of the coilovers while maintaining a balanced ride.
For users seeking more aggressive setups, BC Racing offers the ability to adjust spring rates up or down by 2 kg within the standard range. Adjustments beyond this range require a damper valving change, which must be handled by the manufacturer or a qualified professional. Custom spring and damper combinations are available for track-focused vehicles or builds with specific weight distribution or tire requirements.
Installation of BC Racing coilovers is not a one-size-fits-all process. For example, E36, E46, Z3, and Z4 models require users to determine whether their vehicle has on-center or off-center top plates before ordering. Camber and caster plates are available for off-center top plate applications. Additionally, some models require specific tools or components, such as lock rings, top nuts, and end links, which vary depending on the vehicle platform.
Installation Considerations and Requirements
Installation of BC Racing coilovers typically requires a moderate level of mechanical skill and appropriate tools. While some users may attempt the installation themselves, it is often recommended to seek professional assistance, especially for first-time installations or vehicles with more complex suspension systems. Several key considerations include:
Alignment Requirements: After installation or major height adjustments, an alignment is strongly recommended. Changes in ride height can affect the vehicle's geometry, leading to uneven tire wear if not corrected. BC Racing advises getting an alignment after approximately one week of regular driving to allow the suspension to settle.
Corner Balancing: While not strictly necessary for all users, corner balancing is beneficial for those who plan to heavily track their vehicles or have made significant modifications. It helps ensure even weight distribution across all four corners, optimizing handling and tire wear.
Professional Installation for Certain Models: Some applications, such as E30 or 240Z, require welding of the lower mount to the knuckle. These tasks must be performed by a qualified professional to ensure structural integrity and safety.
Included Components and Tools: BC Racing kits may or may not include specific components such as top mounts, end links, or camber plates, depending on the vehicle. Users should verify the contents of their kit before installation and contact the manufacturer if any required components are missing.
Adjustment Techniques: Proper adjustment of ride height and damping settings is crucial for achieving the desired performance. Users should begin with the factory-preloaded settings and make incremental changes based on their driving experience and conditions. For example, one user noted that adjusting the threaded rod on the rear coilovers to its maximum length still resulted in a 1.5-inch drop, which was more than intended. This highlights the importance of understanding the adjustment range and how it translates to actual ride height.
Common Installation Challenges and User Experiences
Several users have shared their experiences with BC Racing coilover installations, offering insights into common challenges and solutions. One user asked whether adjusting the threaded rod to its full extension was the correct method for lowering the rear suspension, and received confirmation that it was. However, the resulting drop exceeded expectations, suggesting that users should be cautious when making adjustments and measure the actual ride height against their goals.
Another user sought installation instructions from the manufacturer but found them unavailable on the website or forum. This indicates that while BC Racing provides general guidance through its FAQs and tech tips, detailed installation manuals may not be readily accessible to all customers. Users are encouraged to contact BC Racing directly or consult with an authorized reseller for additional support.
For E30 models, a user emphasized the importance of using a spring compressor during installation to safely handle the coil springs. This is a common recommendation across many coilover installations and highlights the need for proper tools and safety precautions.
Customization and Advanced Options
BC Racing offers customization options for users with specific performance needs. For example, extreme drop kits provide greater lowering potential and may include stiffer springs or shorter dampers depending on the build. These kits are ideal for track-prepped vehicles or builds that require a lower center of gravity for improved handling.
Custom spring rates are available but should be used with caution. BC Racing recommends them only for track-focused vehicles or builds with unique weight distributions, tire sizes, or handling characteristics. Users should also consider the impact of stiffer springs on ride comfort and tire wear.
For users planning to modify their vehicle further—such as by adding large wheels or aggressive fender-to-lip clearances—custom coilover setups can help accommodate these changes. However, any modifications should be carefully planned to avoid rubbing or clearance issues.
Post-Installation Recommendations
After installation, it is important to monitor the vehicle’s performance and make any necessary adjustments. BC Racing recommends checking the suspension settings after the first week of driving and performing an alignment if needed. Users should also be aware that the suspension may settle slightly over time, especially with frequent track use or aggressive driving.
For extreme drop kits, users should be mindful of the reduced ground clearance and ensure that the vehicle is not bottoming out, particularly on rough roads or during cornering. If the ride feels too stiff or the vehicle exhibits signs of instability, adjustments to the damping settings or spring rates may be necessary.
Conclusion
BC Racing coilovers offer a high degree of adjustability and performance for a wide range of vehicles. However, successful installation and tuning require careful planning, appropriate tools, and an understanding of the vehicle's suspension system. Users should start with the factory-preloaded settings and make incremental adjustments based on their driving experience and conditions. For those new to coilover installation, seeking professional assistance is strongly recommended, particularly for more complex applications.
By following the manufacturer's guidelines, verifying the contents of the kit, and considering the specific requirements of the vehicle platform, users can achieve optimal results with their BC Racing coilovers. Whether used for street driving, track performance, or aesthetic customization, these coilovers provide a reliable and tunable suspension solution for automotive enthusiasts.