Powerflex Black Series Front Radius Arm To Chassis Bush – Caster Adjustable | BMW F8X M2 / M3 / M4
Upgrade front suspension control and gain additional caster adjustment with the Powerflex Black Series Front Radius Arm To Chassis Bush – Caster Adjustable.
Designed for the BMW F8X M platform, PFF5-4001GBLK replaces the factory rubber radius arm bushes with Powerflex’s performance-focused Black Series polyurethane construction while introducing 5.5mm of caster adjustability.
This allows approximately ±0.5° of caster adjustment, providing greater control over front suspension geometry and allowing the vehicle’s setup to be tailored for improved steering response and performance driving.
Black Series Performance
This version uses Powerflex Black Series material and provides approximately 18% greater stiffness than the original component, helping the radius arm withstand increased loading and reducing unwanted bush deflection.
Reduced movement helps maintain more consistent suspension geometry during hard braking and cornering, making this an excellent upgrade for modified, performance-focused and track-driven F8X M cars.
Caster Adjustable Design
Unlike the standard PFF5-4001BLK bush, the PFF5-4001GBLK provides 5.5mm of caster adjustment, allowing approximately ±0.5° caster offset.
Increasing positive caster can provide:
- Improved steering feel and feedback
- Greater steering stability
- Additional negative camber as the wheels turn
- Improved tyre contact during heavy cornering
- Greater control over front suspension geometry
- More flexibility when setting up the vehicle’s alignment
The additional negative camber generated during steering helps maintain tyre contact with the road when the vehicle is subjected to significant cornering loads.
Improved Front-End Control
Replacing the factory rubber bushes with Powerflex polyurethane reduces unwanted movement within the radius arm mounting point.
Benefits include:
- More precise steering response
- Improved braking stability
- More consistent suspension geometry
- Reduced bush deflection under load
- Increased front-end feedback
- Greater alignment adjustability
- Improved durability compared with ageing factory rubber bushes
Why Choose Powerflex?
Factory rubber suspension bushes are designed to provide a balance between comfort, cost and performance. Over time, repeated loading and environmental exposure can cause rubber bushes to soften and deteriorate, allowing increased movement within the suspension.
Powerflex polyurethane bushes are engineered to provide improved control and durability while maintaining precise suspension operation.
Powerflex Black Series is particularly suited to drivers looking for a more performance-focused suspension setup where chassis precision and geometry control take priority.
Powerflex also backs its polyurethane bushes with a Lifetime Warranty, subject to Powerflex’s applicable warranty terms.
Vehicle Compatibility
Suitable for:
- BMW F87 M2 – N55
- BMW F87 M2 Competition – S55
- BMW F87 M2 CS – S55
- BMW F80 M3
- BMW F80 M3 Competition
- BMW F80 M3 CS
- BMW F82 M4
- BMW F82 M4 Competition
- BMW F82 M4 CS
- BMW F83 M4 Convertible
- BMW F83 M4 Competition Convertible
Powerflex lists the caster-adjustable PFF5-4001G family for the F87 M2, F80 M3 and F82/F83 M4 platforms.
Important Information
This product is intended for performance use and should be installed by a qualified professional.
A professional wheel alignment is recommended following installation, particularly due to the caster-adjustable design.
It is the customer’s responsibility to ensure compatibility with their specific vehicle prior to purchase. If you are unsure, please contact us before ordering.
Gridline Custom Motorsports is not responsible for issues arising from incorrect installation, misuse, or improper product selection.
Due to the nature of performance parts, some items may be special order and subject to supplier availability and lead times.