BMW Front Rotors (Girodisc A1-157)

The Girodisc Front Rotor set for the BMW E9X M3 provides a precision-engineered, lightweight upgrade that enhances braking performance and thermal management without the need for any modifications. Designed as a direct OEM replacement, these two-piece rotors retain full compatibility with the factory calipers and ABS system while reducing rotating and unsprung mass for sharper handling and acceleration.

Vehicle Fitment

This Girodisc front rotor set fits the following BMW models:

• BMW M3 E90 Sedan (2008–2011)
• BMW M3 E92 Coupe (2008–2013)
• BMW M3 E93 Convertible (2008–2013)

Direct bolt-on installation using the OEM calipers and hardware. No spacers, brackets, or modifications required.

Performance and Design

Each rotor weighs significantly less than the factory single-piece iron discs, resulting in reduced rotational inertia and improved suspension response. The 48 curved directional vanes inside the rotor act as a centrifugal pump, pulling air through the disc to increase cooling efficiency and reduce fade during repeated high-performance braking. The central hat is CNC-machined from U.S.-sourced 6061-T6 aluminum for strength and low weight, while the friction ring is Girodisc’s proprietary cast iron, poured and machined entirely in the USA.

Features

- Direct OEM replacement; bolts on with no modifications required.

- Two-piece floating rotor design reduces unsprung and rotating mass.

- Proprietary cast iron rotor ring with 6061-T6 aluminum hat for optimal strength and heat management.

- 48 curved directional vanes improve cooling and minimize fade during aggressive driving or track use.

- Floating mount system with ten high-strength alloy steel drive pins allows for precise axial and radial float.

- Anti-noise spring washers eliminate rattle during street driving while maintaining full float when hot.

- Cadmium-plated hardware and class 12.9 cap screws for corrosion resistance and durability.

- Fully designed, cast, and machined in the USA to Girodisc motorsport-grade tolerances.

Specifications

Rotor Type: Two-piece floating
Vane Count: 48 curved directional
Material: Proprietary cast iron with 6061-T6 aluminum hat
Hardware: 10 alloy steel drive pins with anti-noise spring washers
Fitment: BMW E90, E92, E93 M3 (2008–2013)
Installation: Direct bolt-on
Sold as: Pair (left and right front rotors)

FAQs: BMW E9X M3 Front Rotors (Girodisc)

Do these rotors fit with the OEM calipers? Yes. They are designed as a direct replacement and work perfectly with the factory calipers and pads.

What benefits do these offer over stock rotors? Reduced unsprung mass, faster suspension response, improved cooling, and more consistent braking under heavy use.

Are these noisy during normal street use? No. The use of anti-noise spring washers eliminates rattle while maintaining full floating capability under heat.

Can the rotors be rebuilt? Yes. Once the iron friction rings wear out, they can be replaced independently, allowing reuse of the aluminum hats and hardware.

Ordering Information

Sold and priced per pair. Includes left and right Girodisc front rotors for the BMW E9X M3.