GiroDisc 380mm Front Rotors 2021-2027 BMW M3 M4 M2 G8X

The G80 M3, G82 and G83 M4 and G87 M2 all share a 380 mm front iron rotor, and on track it is the first part of the brake system to wear out. These Giro Disc 2-piece front rotors are a direct replacement for the factory front discs. Each ring has 72 curved vanes against 30 in the factory disc, which moves far more cooling air through the rotor under hard braking.

How GiroDisc builds it

Each assembly is fully floating: a slotted iron ring rides on drive pins around a separate aluminum hat. The ring is machined from a proprietary high-carbon iron casting made to GiroDisc's own specification, which holds up better under hard use. Its 72 curved vanes act as a centrifugal pump, pulling air in through the hub to cool the rotor. GiroDisc makes the hats, rings and drive pins in-house in Bellingham, Washington, from domestically sourced material. The hat is 6061-T6 aluminum with a black anodized finish, and the high-strength alloy steel drive pins are cadmium plated against corrosion. Spring clips and Belleville washers give the ring race-ready float without rattling from loose hardware on the street.

Reusable hats

Because the hat is a separate part, you only replace the iron when it wears out. New GiroDisc rings (D1-282) bolt onto the hats you already have, which costs much less over time than buying complete rotors. Replace the rings at 34 mm minimum thickness, or sooner if a crack reaches the outer edge of the ring.

What's Included

Two assembled front rotors, one per side, each iron ring already mounted to its aluminum hat. Pads are not included.

Specifications

Fitment notes

For G8X cars with factory iron front brakes only, not M Carbon Ceramic. The G81 M3 Touring was not sold in North America, so it is not listed. Replacement rings: D1-282. The product photo is GiroDisc's representative image of its 2-piece rotors.

Fitment