Perrin PSP-BRK-400 Master Cylinder Brace for 2002-07 Subaru WRX/STI

Vehicle Fitment

• 2002-2007 Subaru WRX (all trims)
• 2004-2007 Subaru WRX STI (all trims)
• 2003-2007 Subaru Forester XT (where applicable)

Features

• Reinforces master cylinder attachment point to chassis to reduce firewall flex
• Improves brake pedal stiffness and response under heavy braking
• CNC-machined from 6061-T6 billet aluminum for strength and durability
• Black anodized finish for corrosion resistance and clean appearance
• Includes stainless steel hardware for long-lasting installation
• Adjustable preload screw to fine-tune support tension
• Direct bolt-on upgrade using factory mounting points - no major modifications
• Designed to enhance feel without altering brake hydraulics

Specifications

• Part Number: PSP-BRK-400
• Material: 6061-T6 billet aluminum
• Finish: Black anodized
• Hardware: Stainless steel included
• Mount Location: Between firewall/master cylinder and driver-side shock tower
• Orientation: Left-hand drive vehicles only
• Fitment: Subaru WRX, WRX STI, Forester XT (2002-2007)
• Improves pedal stiffness and reduces chassis flex during braking

Included Components

• 1x Perrin Master Cylinder Brace (PSP-BRK-400)
• 1x M12 socket set cup
• 1x M12 jam nut
• 1x M6 fin hex nut
• 4x M6 flat washers
• 3x M6 button head socket cap screws
• 1x Fender washer
• 1x M6 short arm hex key
• 1x M4 short arm hex key
• Installation instructions & warranty information

Product Description

The Perrin PSP-BRK-400 Master Cylinder Brace is engineered specifically for 2002-2007 Subaru WRX, 2004-2007 WRX STI, and select Forester XT models to stiffen the firewall area where the brake master cylinder and booster mount. Subaru's factory setup uses thin sheet metal that can flex under repeated braking forces, leading to a softer pedal feel and reduced responsiveness. By bridging the master cylinder to the driver-side shock tower with a rigid CNC-machined aluminum brace, this upgrade dramatically reduces flex and gives drivers a firmer, more consistent brake pedal response - especially beneficial during spirited driving or track use.

This bolt-on solution includes all necessary stainless hardware and features an adjustable preload screw allowing owners to fine-tune the support tension. The black anodized finish not only resists corrosion but also keeps the engine bay looking clean. Easy to install with basic tools, the Perrin Master Cylinder Brace is a popular performance upgrade for Subaru enthusiasts looking to enhance braking feel without changing brake components themselves.