Thumbnail for Two-piece Girodisc brake rotors with curved slots with black rotor hats and gold-colored hardware.

Thumbnail for Close-up image of a Girodisc 2-piece brake rotor viewed from the back

Two-piece Girodisc brake rotors with curved slots with black rotor hats and gold-colored hardware.

Close-up image of a Girodisc 2-piece brake rotor viewed from the back

Girodisc Audi with Brembo 18Z Front Rotors

These Girodisc A1-309 two-piece front rotors are purpose-built for Audi models using the Brembo “18Z” 6-piston caliper (Cayenne/Q7/Touareg sourced). They bolt to the car and work with 18Z calipers while reducing unsprung weight and improving cooling versus one-piece rotors.

Vehicle Fitment

Audi S4 (B5) – Front, with Brembo 18Z caliper conversion
Audi A6 (C5) 2.7T – Front, with Brembo 18Z caliper conversion
Audi Allroad (C5) 2.7T – Front, with Brembo 18Z caliper conversion

Fitment note: Minor clearancing on the bottom of the upright is required on C5 chassis per Girodisc instructions. Will not fit C5 A6 4.2 V8, RS6, or Allroad 4.2 V8.

Lightweight, High-Flow Design

High-carbon iron rings with curved internal vanes act as a centrifugal pump to draw cooling air through the disc. Reusable 6061-T6 aluminum hats and cadmium-plated drive pins control thermal growth while keeping street noise in check.

Features

Direct fit for 18Z caliper swaps on B5 S4 / C5 2.7T (A6, Allroad)
Two-piece floating construction reduces unsprung weight
High-carbon rings, curved vanes for efficient cooling
Reusable aluminum hats; new hardware included
Manufactured and assembled in Bellingham, WA
Sold/priced per pair

A1-309 FAQs

Will these fit C5 4.2 V8 or RS6? No. These are for B5 S4 and C5 2.7T cars only when running 18Z calipers.

Is any modification needed? On C5 chassis, Girodisc specifies minor upright clearancing; a guide/video is provided.

Do I need different brake lines or brackets? No additional lines or brackets are required for standard 18Z swap geometry.

What rings do I use later? Use D1-309 front replacement rings.

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