GiroDisc A1-146 380 mm 2-Piece Slotted Front Rotors for 991 GT3 / GT3RS / GT2RS

Vehicle Fitment

• Porsche 911 (991) GT3 / GT3 RS / GT2 RS - front axle, non-PCCB (iron-disc) variants

Features

• 2-piece floating rotor - aluminum hat + cast-iron disc ring to reduce unsprung and rotational mass
• Vented disc with curved-vane internal design for efficient heat dissipation under heavy braking
• Slotted rotor surface - improves pad bite, cleans debris/gases, and enhances wet-weather braking performance
• Direct OEM bolt-on replacement - uses factory calipers and pads, no modifications required
• Floating-mount system with high-strength drive pins and anti-noise spring washers to allow thermal expansion without warping or rattle
• Rotors lighter than stock - improves suspension response and reduces unsprung mass for better handling
• Disc-ring is replaceable - you can swap worn rings without replacing the hat to save cost and waste
• Maintains factory brake bias and ABS function (when used on original-equipment calipers & pads)

Specifications

• Part Number: A1-146
• Rotor Diameter: 380 mm
• Construction: 2-piece floating (6061-T6 aluminum hat + proprietary cast-iron ring)
• Surface: Vented, slotted with curved-vane internal vanes for cooling
• Sold as: Set of 2 (front left + right)
• Mounting: Floating-mount with alloy drive pins + anti-noise spring washers

Included Components

• 1x Pair of front brake rotors (left + right), 380 mm slotted 2-piece design
• All necessary floating-mount hardware (drive pins, washers, fasteners)

Product Description

The GiroDisc A1-146 2-Piece Slotted Front Rotors provide a high-performance brake upgrade for Porsche 991-series GT3, GT3 RS, and GT2 RS (non-PCCB) cars. By replacing the heavier stock iron rotors with a lighter, ventilated, and slotted 2-piece design, A1-146 reduces unsprung and rotational mass, improving suspension response, steering feel, and braking performance - especially under aggressive driving or track conditions. The curved-vane ventilation, combined with slotted rotor surfaces, helps dissipate heat more efficiently and purge pad gasses or debris, which improves consistency under repeated hard braking.

These rotors are a direct OEM-style bolt-on - they work with original calipers and pads, preserving factory brake bias and ABS system behavior. The floating-mount system accommodates thermal expansion without warping or brake judder, while anti-noise washers keep operation smooth and quiet. Additionally, because the disc ring is replaceable, you don't need to replace the entire rotor when the rings wear - a cost-effective advantage for track or performance-oriented owners. GiroDisc A1-146 offers a balanced mix of performance, durability, and practicality for both spirited street driving and demanding track use.