Whiteline Anti Geometry Kit - Front Control Arm Lower Inner Rear Bushing | 2007-2014 Subaru WRX / STI Sedan & Hatch (KCA425)

Take full control of your WRX or STI's front suspension geometry with the Whiteline KCA425 Anti Geometry Kit. Replacing the front lower control arm's vertically-mounted inner rear bushing with a high-performance, low-compliance bearing, the KCA425 allows 2007-2014 WRX and STI owners to tune their front suspension geometry across a spectrum from anti-lift to anti-dive — a level of geometry tuning previously unavailable on this platform. Positive static caster gains are also achievable through the bearing's offset orientation, making the KCA425 one of the most sophisticated and versatile front suspension upgrades available for the GR/GV WRX and STI.

Note: This is an advanced suspension geometry tuning component. Geometry changes should be made in conjunction with a wheel alignment and ideally with input from an experienced alignment technician or suspension tuner familiar with anti-lift/anti-dive geometry. Recommended spacers are required to achieve specific geometry settings.

Key Features:

• Replaces front lower control arm inner rear vertically-mounted bushing
• High-performance, low-compliance synthetic elastomer with performance bearings
• Tunable geometry: adjustable from anti-lift to anti-dive via recommended spacers
• Positive static caster gain achievable via offset bearing orientation
• Optimum dynamic alignment through low-compliance bearing design
• Fits 2007-2014 Subaru WRX and STI — sedan and hatch
• Whiteline quality and engineering
• 3.8 lbs

Performance Benefits:

• Tunable Anti-Lift / Anti-Dive Geometry: Adjust the front suspension's response to braking and acceleration forces — dial in anti-lift for reduced nose rise under acceleration, or anti-dive for reduced nose dive under braking, or find the optimal balance for your driving style and application
• Caster Gain: The offset bearing orientation allows positive static caster to be added, improving straight-line stability, steering return-to-centre, and camber gain in corners
• Optimum Dynamic Alignment: Low-compliance bearing design minimizes bushing deflection under load, maintaining more consistent wheel alignment through suspension travel and under cornering, braking, and acceleration forces
• Improved Steering Precision: Reduced bushing compliance provides more direct, precise steering response and improved front end feel
• Reduced Understeer: Correct anti-geometry settings can reduce the understeer tendency of the AWD WRX/STI platform under braking and turn-in
• Geometry Consistency: Low-compliance bearings maintain geometry more consistently than factory rubber bushings, providing more repeatable handling behaviour

Specifications:

• Brand: Whiteline
• Part Number: KCA425
• Position: Front lower control arm — inner rear bushing
• Bushing Type: Low-compliance synthetic elastomer with high-performance bearings
• Geometry Adjustment: Anti-lift to anti-dive (via recommended spacers)
• Caster Adjustment: Positive static caster gain via offset bearing orientation
• Application: 2007-2014 Subaru WRX / STI — sedan and hatch
• Weight: 3.8 lbs
• Barcode: KCA425

Fitment Information:

• 2007-2014 Subaru WRX — sedan (GR chassis) and hatch (GH chassis)
• 2007-2014 Subaru WRX STI — sedan (GR chassis) and hatch (GV chassis)
• Note: Front lower control arm inner rear bushing position only — does not replace all front control arm bushings
• Note: Recommended spacers required to achieve specific anti-lift/anti-dive geometry settings — verify spacer requirements with Whiteline documentation
• Note: Wheel alignment required after installation — geometry changes are significant and must be properly set
• Installation: Professional installation recommended — front control arm bushing replacement requires pressing equipment and suspension knowledge

What's Included:

• Whiteline KCA425 anti geometry kit — front lower control arm inner rear bushing with high-performance bearings
• Note: Recommended spacers for geometry adjustment — verify if included or if they must be sourced separately per Whiteline documentation
• Note: Refer to Whiteline installation and setup guide for geometry adjustment procedure and spacer combinations

Installation Notes:

• Professional installation recommended
• Front lower control arm must be removed for bushing replacement — requires pressing equipment
• Inspect control arm, ball joint, and all surrounding suspension components while the area is accessible
• Torque all fasteners to Whiteline and Subaru specifications with suspension at ride height
• Full wheel alignment required after installation — do not drive without alignment check
• Consult Whiteline's setup guide for recommended spacer combinations for your specific geometry target
• Inform your alignment technician of the geometry changes made — anti-geometry settings affect alignment targets

Anti-Lift and Anti-Dive Geometry — What It Means:

Anti-lift and anti-dive are suspension geometry characteristics that describe how the front suspension responds to the longitudinal forces of acceleration and braking. Under braking, weight transfers forward, compressing the front suspension — this nose dive is partly a function of the suspension geometry. Anti-dive geometry is designed to resist this nose dive by using the suspension link angles to generate a force that opposes the compression under braking. Similarly, anti-lift geometry resists the tendency of the front of the car to rise under acceleration as weight transfers rearward.

The factory WRX and STI suspension has a fixed amount of anti-lift and anti-dive built into its geometry — a compromise between ride quality, handling, and tyre wear that suits the broad range of drivers and conditions the car is designed for. The Whiteline KCA425 allows this geometry to be adjusted by changing the angle of the front lower control arm's inner rear pivot point — the point that most directly influences the anti-lift/anti-dive characteristics of the front suspension. By using the kit's recommended spacers to alter the bearing's position, the effective angle of the control arm's inner rear pivot can be changed, shifting the geometry toward more anti-dive (better braking stability, less nose dive) or more anti-lift (better acceleration stability, less nose rise) depending on the driver's preference and application.

Caster Adjustment — The Additional Benefit:

Caster is the angle of the steering axis when viewed from the side of the vehicle. Positive caster — where the top of the steering axis leans rearward — provides several handling benefits: improved straight-line stability, stronger steering return-to-centre, and increased camber gain as the wheel is steered. The factory WRX and STI have a fixed caster angle that cannot be adjusted through the standard alignment process. The KCA425's offset bearing orientation allows positive static caster to be added by rotating the bearing to its offset position, effectively moving the inner rear pivot point of the control arm and changing the caster angle. This caster gain is a meaningful handling improvement for performance driving, particularly for track use where maximum cornering grip and steering precision are priorities.

Low-Compliance Bearings — Why They Matter:

The factory front lower control arm inner rear bushing is a rubber bushing that provides compliance — it flexes under load, absorbing road noise and vibration but also allowing the control arm to move slightly from its designed position under cornering, braking, and acceleration forces. This compliance means that the wheel's alignment changes dynamically as the suspension is loaded, reducing the consistency and precision of the front suspension's behaviour. The KCA425 replaces this rubber bushing with a high-performance, low-compliance bearing that resists deflection under load, maintaining the control arm in its designed position more consistently. The result is more precise, consistent wheel alignment through all driving conditions — improving steering feel, front end grip, and handling predictability.

2007-2014 Subaru WRX / STI — Platform Context:

The GR/GH/GV-chassis Subaru WRX and STI (2007-2014) use a double-wishbone front suspension that provides excellent geometry for performance tuning. The platform is extremely popular for performance modification, with a large and active aftermarket. The front lower control arm inner rear bushing is a key geometry point on this suspension — its position and compliance directly influence caster, anti-lift, and anti-dive characteristics. The Whiteline KCA425 is one of the most sophisticated geometry tuning tools available for this platform, allowing experienced drivers and tuners to optimize the front suspension geometry for their specific driving style, track, and setup.

Why Whiteline?

Whiteline is an Australian manufacturer of suspension geometry correction and performance suspension components with decades of experience developing solutions for a wide range of vehicles. Their anti geometry kits represent some of the most advanced suspension tuning components available for the platforms they support, developed with genuine engineering knowledge of suspension geometry and its effects on vehicle dynamics. The KCA425 is a well-established, proven product for the GR/GV WRX and STI, trusted by performance drivers, alignment specialists, and suspension tuners worldwide.

Perfect For:

• 2007-2014 Subaru WRX and STI owners wanting to tune front suspension anti-lift/anti-dive geometry for their specific driving style
• WRX/STI track day and time attack builds wanting caster gain and low-compliance front suspension geometry for maximum front end grip
• WRX/STI owners experiencing understeer under braking or turn-in who want to address it through geometry adjustment
• Performance-oriented WRX/STI owners wanting the most sophisticated front suspension geometry tuning available for their platform
• Anyone wanting Whiteline's KCA425 anti geometry kit for improved dynamic alignment consistency and geometry tunability on their 2007-2014 WRX or STI

Perfect For: 2007-2014 Subaru WRX and STI owners seeking Whiteline KCA425 anti geometry kit for tunable anti-lift/anti-dive geometry, positive caster gain, low-compliance front suspension, and optimum dynamic alignment consistency.

Pro Tip: Work with an alignment technician or suspension tuner who understands anti-geometry settings when setting up the KCA425 — the geometry window it provides is powerful, but the optimal setting depends on your specific suspension setup, tyre choice, and driving application. A tuner with experience on the GR/GV WRX/STI platform will be able to guide you to the right spacer combination and alignment targets for your goals.

Anti Geometry | Tunable Anti-Lift to Anti-Dive | Caster Gain: 2007-2014 Subaru WRX / STI sedan and hatch. Spacers required for geometry adjustment. Alignment required after installation. 3.8 lbs. Professional installation recommended.

Unlock advanced front suspension geometry tuning on your WRX or STI with Whiteline KCA425 — tunable anti-lift to anti-dive, positive caster gain, low-compliance bearings, optimum dynamic alignment for 2007-2014 Subaru WRX and STI.