GiroDisc D1-307 Front Replacement Rotor Rings 348mm Toyota Supra BMW G-Chassis

Vehicle Fitment

• 2020-2026 Toyota GR Supra 3.0 (Base, Premium, A91 Edition, A91-MT Edition, 45th Anniversary Edition, RWD, 3.0L Turbo I6)
• 2019-2026 BMW Z4 M40i (G29, RWD, 3.0L Turbo I6, Equipped with GiroDisc A1-307 Front Rotors)
• 2020-2026 BMW M340i (G20/G21, RWD/AWD, Equipped with GiroDisc A1-307 Front Rotors)
• 2021-2026 BMW M440i (G22/G23/G26, RWD/AWD, Equipped with GiroDisc A1-307 Front Rotors)
• 2022-2026 BMW M240i (G42, RWD/AWD, Equipped with GiroDisc A1-307 Front Rotors)
• 2018-2026 BMW X3 M40i (G01, AWD, Equipped with GiroDisc A1-307 Front Rotors)
• 2018-2026 BMW X4 M40i (G02, AWD, Equipped with GiroDisc A1-307 Front Rotors)

Fitment Notes

• Replacement rotor rings for GiroDisc A1-307 front rotor assemblies only.
• Not compatible with OEM one-piece brake rotors.
• Not compatible with factory two-piece rotor hats or other aftermarket hats.
• Requires reuse of existing GiroDisc aluminum hats.
• Includes replacement mounting hardware.
• Front axle application only.

Features

• Direct replacement friction rings for GiroDisc A1-307 front rotor assemblies.
• Manufactured from proprietary high-carbon cast iron.
• Directional curved-vane internal cooling design.
• Improved thermal stability under repeated high-heat braking.
• Fully compatible with existing GiroDisc floating hardware systems.
• Maintains GiroDisc braking performance without replacing hats.
• Precision-machined for consistent rotor balance and thickness.
• Excellent resistance to cracking and rotor distortion.
• Designed for both street and track use.
• Manufactured in the USA.

Specifications

• Manufacturer: GiroDisc
• Part Number: D1-307
• Position: Front
• Rotor Type: Replacement Rotor Rings Only
• Rotor Diameter: 348mm
• Material: High-Carbon Cast Iron
• Vane Design: Directional Curved Vane
• Configuration: Floating Two-Piece Rotor Replacement Ring
• Minimum Recommended Replacement Thickness: 34mm
• Sold As: Pair

Included Components

• 2x Front Replacement Rotor Rings
• 1x Replacement Hardware Kit

Product Description

The GiroDisc D1-307 Front Replacement Rotor Rings provide a cost-effective solution for refreshing worn GiroDisc A1-307 two-piece front brake rotors without replacing the reusable aluminum hats. Designed specifically for GiroDisc floating rotor assemblies, these replacement rings restore braking performance while retaining the advantages of the original lightweight two-piece design.

Manufactured from GiroDisc's proprietary high-carbon iron casting, the D1-307 rings are engineered to withstand extreme heat cycles encountered during aggressive street driving, track days, and competition use. The directional curved-vane internal structure promotes efficient airflow through the rotor, helping reduce operating temperatures and maintain consistent braking performance.

Each kit includes a pair of front rotor rings along with new mounting hardware for proper installation. These replacement rings are intended exclusively for use with GiroDisc A1-307 rotor hats and are not compatible with OEM or other aftermarket two-piece rotor assemblies.