COBB Front Roll Center Bump Steer Kit – 2008-2021 Subaru WRX/ STI

Cobb Front Roll Center / Bump Steer Kit — 2008-2021 Subaru WRX / STI

The Cobb Front Roll Center and Bump Steer Kit for the 2008-2021 Subaru WRX and STI corrects the roll center drop and increased bump steer that occur when these platforms are lowered. Extended ball joint studs restore the roll center toward factory geometry at the new ride height, while adjustable tie rod ends allow bump steer to be corrected after lowering. The result is a lowered WRX or STI that handles with the predictability and steering feel the factory geometry was designed to deliver.

DETAILS

• Platform: 2008-2021 Subaru WRX EJ255/FA20DIT and 2008-2021 WRX STI EJ257
• Corrects roll center drop from lowering — extended ball joint studs raise outer pivot
• Reduces bump steer — adjustable tie rod ends correct fore-aft geometry
• Designed for 1-1.5 inch lowering: springs or coilovers
• Addresses both roll center and bump steer simultaneously
• Four-wheel alignment required after installation
• All hardware included

Roll Center and Bump Steer: Two Lowering Problems Solved Together

When a car is lowered, the front suspension geometry changes in ways the factory alignment cannot fully correct. One issue is the roll center — the geometric point around which the front suspension rolls during cornering. As the car is lowered, the roll center drops relative to the center of gravity, increasing the moment arm between them and making the car roll more for a given lateral force. A roll center correction kit raises the outer tie rod end mounting point to restore a more appropriate roll center height after lowering. The second issue is bump steer — the tendency of the wheel to change toe angle as the suspension travels up and down. On a lowered car, the factory tie rod geometry produces more bump steer than at factory ride height, making the steering feel nervous and inconsistent over bumps and during suspension travel in corners.

Extended Ball Joints, Adjustable Tie Rods, and Alignment After Installation

The Cobb Front Roll Center and Bump Steer Kit provides extended ball joint studs at the front lower ball joints that raise the outer suspension pivot point, restoring the roll center closer to factory geometry at the new, lower ride height. The extended tie rod ends are adjustable — they allow the tie rod geometry to be corrected for bump steer by changing the effective length and angle of the tie rod at the wheel. After installation, a four-wheel alignment is required to set the front toe, camber, and caster correctly at the corrected geometry. The kit addresses both roll center and bump steer issues simultaneously with a single installation, sized correctly for WRX and STI builds running 1-1.5 inch lowering springs or coilovers.

What’s in the Box

• Extended front ball joint studs
• Adjustable front tie rod ends
• All hardware

Why Choose Cobb Tuning

Cobb Tuning has been developing performance software and hardware for turbocharged enthusiast vehicles since 1999. Founded in Austin, Texas, Cobb built its reputation on the Accessport and expanded into a full catalog of hardware engineered to complement it. Every OTS map is developed in-house on real vehicles, and every hardware product is validated as part of a complete system — not sourced and sold in isolation. That integrated approach is why Cobb produces consistent, reliable results across the builds we see every day.

The RallySport Take

The Cobb Front Roll Center and Bump Steer Kit for the GR and VA WRX and STI is the correct geometry correction for any lowered build on these platforms. Lowering consistently produces two handling issues on these cars — roll center drop and increased bump steer — that factory alignment adjustments cannot fix because they are geometry problems, not alignment setting problems. The Cobb kit addresses both with one purchase. After installation with a proper four-wheel alignment, the lowered WRX or STI handles with the predictability and steering precision the factory suspension geometry intended — just lower.

Fitment

Year	Make	Model	Notes
2008-2021	Subaru	WRX	EJ255/FA20DIT MT/CVT
2008-2021	Subaru	WRX STI	EJ257 MT