Girodisc A1-309
Pair of two-piece floating front brake rotors
Girodisc is an American company founded in 2003 in California and based since 2007 in Bellingham, Washington, where it designs and builds two-piece floating brake rotors for sports cars, supercars and track cars. The iron castings for the friction rings are poured in the USA and every part is machined and inspected in the Girodisc factory.
The cast iron friction ring has curved internal vanes that pump air outwards and bring temperatures down quickly, and it is joined to the 6061-T6 aluminium hat with floating steel drive pins. The ring can therefore expand freely with heat, self-centres between the pads and resists warping and judder even after many laps. Compared with the original rotor it also reduces unsprung weight.
They are the choice of many enthusiasts who take their car to track days: they replace the original rotors, including factory-fitted Brembo or other brands, and work with the standard calipers. The first purchase is the pair of complete rotors with hats; once the ring is worn, often after more than one season depending on use, only the pair of replacement rings is needed (D1 series for the front, D2 for the rear).
Finish: curved slots
Construction: two-piece floating
Ring material: cast iron
Package contents: 2 complete rotors with hats (left A1-309SL and right A1-309SR)
Pair code: A1-309
Part numbers: A1-309SL, A1-309SR
Replacement rings: D1-309SL, D1-309SR
Images for reference only: the photo is a generic Girodisc picture; hat shape, drilling and ring pattern vary by application. The technical drawing shows the correct orientation of the left and right rotors.
When the ring is worn, here is the matching pair of Girodisc D1-309 replacement rings. To complete the system see the Girodisc brake pads and all Girodisc rotors for Audi.
Availability: usually shipped within 3-4 working days from the European warehouse; codes not in stock are delivered within about 15 days. Contact us for up-to-date availability.
Compatibility:
Audi S4 Quattro 2.7 Twin Turbo (B5) 1997-1999
Audi S4 Quattro 2.7 Twin Turbo (B5) 1999-2001
Audi S4 Quattro Avant 2.7 Twin Turbo (B5) 1997-1999
Audi S4 Quattro Avant 2.7 Twin Turbo (B5) 1999-2001
List supplied by the European Girodisc distributor. If your car is not listed or you have any doubt, contact us before ordering.
