XYZ Racing Hollow Rear Brake Kit — Subaru IMPREZA STI GDB(E/F) φ 315/ φ 191 (2005-2007)

The GDB Impreza STI puts power down through all four wheels, so it carries corner-exit speed that punishes the rear axle far harder than any rear-drive car would. The XYZ Racing rear big brake kit for the 2005-2007 Subaru Impreza STI GDB(E/F) answers that with a 315mm two-piece floating rear disc, handing the back of the car the thermal headroom the factory Brembo setup starts to run short of on a hot track day.

This is a rear-specific kit, a matched pair of left and right corners, built either to balance a front brake upgrade or to cure the rear-end fade that creeps in under repeated heavy braking. Three pad compounds, Street, Sport and Racing, let you match it to how the car is actually driven, from fast-road duty to back-to-back sessions at Cadwell or Anglesey.

What this rear big brake kit does for your 2005-2007 Subaru Impreza STI

The 315mm rear disc gives you a larger swept area and more mass to soak up heat, so the rear brakes hold their bite deeper into a session instead of going long and wooden after a handful of hard stops. On a turbo AWD car that loads its rear axle hard turning in, that means a more stable, more predictable platform into slow corners. The Racing pad option resists fade at the temperatures a tracked GDB genuinely sees, the Sport compound covers spirited fast-road with the odd track day, and the Street compound keeps cold bite sharp and dust down for the daily run. Caliper finish is yours to set, painted Red, Yellow, Gold, Black or Anodized Black at no cost, or a Custom Color in any Pantone, so the upgrade reads as deliberate behind the wheels rather than an afterthought.

About the rear big brake kit

XYZ Racing builds this as a rear-axle big brake kit specifically for the GDB(E/F) Impreza STI, pairing the 315mm two-piece floating disc with a caliper and bracket package sized to clear the chassis without improvisation. The floating disc that lets the friction ring expand against its alloy bell trims rotating and unsprung mass at the rear and cuts thermal distortion, which helps both the dampers and the brakes’ cold response; the caliper body is a hollow-cast forging as standard, with an optional Hollow Racing upgrade rated to 1000C and a two-year warranty for dedicated track work. You select the pad compound at point of order: Street for road use, Sport for spirited fast-road driving, and Racing for track work where pad fade is the limiting factor. Painted caliper colours, Red, Yellow, Gold, Black and Anodized Black, come at no extra cost, with a Custom Pantone for £150 plus premium polished-forged and candy finishes, while disc faces are drilled or slotted at the same price and the centre bell upgrades to a five-colour anodized two-tone or titanium at checkout. The whole package exists to restore rear braking balance once front grip and front stopping power have been pushed beyond standard.

Fitment for the Subaru Impreza STI GDB(E/F) (2005-2007)

This kit is cut for the GDB(E/F) Impreza STI built between 2005 and 2007, the hawkeye-era cars, in the 315mm rear disc specification. Confirm your chassis code reads GDB and that the build year falls inside the 2005-2007 window before ordering, since earlier GD-series STIs run different rear hardware.

What buyers also search for

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Choose your pad compound and caliper colour from the options above, then build your GDB rear brake kit.