GiroDisc D2-007 Slotted Rear Replacement Rotor Rings Subaru WRX STI 04-17 316mm

Vehicle Fitment

• 2004-2017 Subaru WRX STI - Rear axle (replacement rings for GiroDisc A2-007 rear rotor kit)

Fitment Notes

• Replacement rings only - these are cast iron rotor rings sold without hats; the existing GiroDisc aluminum hats from the A2-007 kit are reused with new rings and fresh hardware
• Compatible with GiroDisc A2-007 hats ONLY - these rings are not designed to work with OEM Subaru hats, any other brand's hats, or factory 2-piece rotor hats
• Due to tight tolerances between the rear caliper and the rotor hat, minor arching of the rear outboard brake pad may be required for clearance; brake pads purchased directly from GiroDisc for this application are pre-arched on their CNC equipment for a plug-and-play installation
• Sold as a pair (2 rings - one complete rear axle set); all required replacement hardware is included
• 2018+ Subaru WRX STI uses a different rear rotor kit (A2-185) and different replacement rings - use GiroDisc D2-185 for those vehicles, NOT D2-007
• For the front axle replacement rings (A1-007 front kit), see GiroDisc D1-007 (326 mm)
• Rotor ring installation should be performed by a qualified brake technician; GiroDisc provides full re-assembly instructions with each ring set

Features

• Restores A2-007 rear rotor assemblies to new performance - worn or cracked rings are the only consumable component of the GiroDisc 2-piece system; replacing them with D2-007 rings returns full braking performance and thermal capacity while retaining the existing aluminum hat and floating hardware
• Proprietary GiroDisc cast iron - rings are machined from GiroDisc's proprietary cast iron alloy, poured and machined entirely in the USA from domestically sourced materials; to the same specification used by professional racing organisations
• Curved internal vanes - the replacement rings share the same directional vane geometry as the original A2-007 rings, acting as a centrifugal pump to draw cooling air in through the hub and drive it outward through the disc for rear axle thermal management
• Slotted rotor surface - precision-cut slots on the ring face continuously sweep brake dust, gases, and debris from the pad contact zone for consistent bite and resistance to glazing
• All replacement mounting hardware included - new drive pins, grade 12 cap screws, hardened washers, and anti-noise spring washers are supplied with each ring set; re-use of old hardware is not required or recommended
• Significant cost saving versus full assembly replacement - purchasing D2-007 rings and reusing existing A2-007 aluminum hats costs substantially less than replacing complete rear rotor assemblies
• Manufactured in the USA from domestically sourced materials (GiroDisc, Bellingham, WA)

Specifications

• Part Number: D2-007
• Product: Rear Replacement Rotor Ring Set
• Quantity: 2 rings (1 pair - rear axle set) + complete hardware kit
• Rotor Outer Diameter: 316 mm
• Rotor Style: Slotted
• Ring Material: Proprietary GiroDisc cast iron (poured and machined in USA)
• Compatible Assembly: GiroDisc A2-007 (Subaru WRX STI 2004-2017 Rear Rotors)
• A2-007 Rotor Weight: approx. 11 lbs per rotor (vs. approx. 18 lbs OEM)
• Hat Included: No - reuse existing GiroDisc A2-007 aluminum hats
• Hardware Included: Yes - grade 12 cap screws, hardened washers, anti-noise spring washers, and drive pins for both rings
• Pad Note: Minor arching of rear outboard pad may be required; GiroDisc-supplied pads for this application are pre-arched
• 2018+ STI Rear Rings: D2-185 (different application - A2-185 kit)
• Front Axle Rings: D1-007 (326 mm, for A1-007 front kit)
• Country of Manufacture: USA (Bellingham, WA)

Included Components

• 2x GiroDisc proprietary cast iron rear replacement rotor rings (316 mm, slotted)
• 2x Complete hardware kits (new grade 12 cap screws, hardened washers, anti-noise spring washers, drive pins - one kit per ring)
• Re-assembly instructions

Product Description

The GiroDisc D2-007 is a pair of 316 mm rear replacement rotor rings for the GiroDisc A2-007 two-piece rear rotor kit fitted to the 2004-2017 Subaru WRX STI. The GiroDisc two-piece system is engineered to be serviceable over the long term: the 6061-T6 aluminum hat and floating hardware are fully reusable across multiple ring service cycles, while only the cast iron rings need replacement at end of service life. Purchasing D2-007 rings and reusing the existing A2-007 hats is substantially more cost-effective than replacing complete rear rotor assemblies - a meaningful consideration for STI owners who use their cars regularly on track or in tarmac rally events.

The replacement rings are machined from GiroDisc's proprietary cast iron alloy, poured and machined entirely in-house at their Bellingham, WA facility from domestically sourced materials, and carry the same directional curved vane geometry as the original A2-007 rings. This vane geometry functions as a centrifugal pump during rotation, pulling cooling air in through the hub and driving it outward through the rear disc face to maintain lower operating temperatures under sustained rear braking loads. The slotted ring face keeps the pad contact surface swept clear of debris and outgassed compounds throughout the ring's service life. All required replacement hardware - new grade 12 cap screws, hardened washers, anti-noise spring washers, and drive pins - is included with each D2-007 set; old hardware should not be reused.

One important installation note: due to the tight clearance between the rear caliper and the rotor hat on the STI platform, the rear outboard brake pad may require minor arching for clearance. A disclaimer and instructions for this modification are included with the rings. Brake pads purchased directly from GiroDisc for this application are pre-arched on their CNC equipment, providing a plug-and-play fit. Owners of the 2018+ Subaru WRX STI should order GiroDisc D2-185 instead, as the later STI uses a different rear rotor kit (A2-185) with a different ring diameter. Front axle replacement rings for the A1-007 front kit are GiroDisc D1-007. All D2-007 components are manufactured at GiroDisc's Bellingham, WA facility.