GiroDisc A1-220 400 mm 2-Piece Slotted Front Rotors for 2012-2021 BMW M2/M3/M4

Vehicle Fitment

• BMW M2 (F87, M2 Competition / CS) - 2016-2021
• BMW M3 (F80 / LC-F80) - 2012-2018 (S55 3.0 L Twin-Turbo)
• BMW M4 (F82 / F83 / LC-F82/F83) - 2014-2020 (S55 3.0 L Twin-Turbo)

Features

• 2-piece floating rotor design - aluminum hat + cast-iron disc ring for reduced unsprung & rotational mass
• Large 400 mm diameter vented and slotted disc - maximizes braking surface and heat dissipation under heavy load or track use
• Curved-vane internal ventilation - acts as a centrifugal "pump" to pull cooling air through the rotor under braking, improving thermal management
• Floating-mount system using high-strength alloy steel drive pins with anti-noise spring washers - allows thermal expansion with zero cold-start rattle
• Direct bolt-on replacement - compatible with stock calipers and hub bolt pattern, no adapters or machining required
• Replaceable cast-iron rotor rings - aluminum hats remain reusable, reducing long-term maintenance and cost
• Maintains factory brake geometry, bias, and ABS compatibility when used with appropriate pads - no overhaul needed
• Sold as a matched pair (front left + right), ready to install

Specifications

• Part Number: A1-220
• Rotor Diameter: 400 mm
• Construction: 2-Piece Floating (6061-T6 aluminum hat + proprietary cast-iron disc ring)
• Disc Surface: Slotted & vented with curved internal vanes
• Mount Type: Floating mount - 12 alloy steel drive pins + anti-noise washers and hardened cap screws
• Sold As: Pair (front left + right rotors) including floating-mount hardware

Included Components

• 2x Front brake rotors (left and right), 400 mm slotted/vented, 2-piece floating
• Floating-mount hardware (drive pins, anti-noise washers, cap screws/bolts)

Product Description

The GiroDisc A1-220 400 mm Slotted Front Rotor kit is engineered for high-performance braking upgrades on 2012-2021 BMW M-series cars - including M2, M3, and M4 models. By replacing the stock one-piece rotors with a floating, 2-piece aluminum-hat + cast-iron design, A1-220 reduces unsprung and rotating mass, which improves suspension response, braking modulation, and steering feel. The large 400 mm diameter and slotted, vented surface increase braking surface area and enhance heat dissipation - especially beneficial for spirited driving, track days, or heavy-duty braking.

Curved-vane internal ventilation actively pulls air through the rotor during braking, keeping operating temperatures lower and minimizing fade. The floating-mount construction accommodates thermal expansion, while anti-noise washers eliminate cold-start clicking or rattles typical of many two-piece rotors. Because the rotor mounts directly using OEM calipers and hubs - no adapters - installation remains straightforward and reversible. Additionally, when rings wear out, you only need to replace the cast-iron rings, reusing the aluminum hats, which keeps long-term maintenance costs down. For M-series owners seeking a strong, durable, and serviceable brake rotor upgrade without altering factory brake bias or systems - A1-220 is an excellent, proven upgrade.