These Girodisc D1-122 front replacement braking surfaces (350 × 34 mm) allow you to replace the braking surfaces on your GIRODISC floating-caliper rotors for your Porsche 911 (991.1) Carrera S, 4S, and GTS (2011–2015), Porsche Boxster (981) Spyder (2015–2016), while retaining the compatible rotors after inspection. These cast-iron pads maintain the floating mounting’s functionality and facilitate maintenance of a braking system subjected to repeated stress. Sold in pairs, without rotors.
The curved internal cooling fins channel air through the disc to dissipate heat during repeated braking. The floating mounting limits stresses caused by thermal expansion differences between the track and the caliper housing and helps the track center itself between the pads, maintaining consistent contact when hot.
New brake pads must be installed with new discs or rotors. Their shape and compound must match the mounting configuration, cast iron type, and intended use; follow the specific requirements for this part number and perform the prescribed break-in procedure.
Each application is subject to its specific brake system configuration, calipers, and any requirements for brake pads or spacers. Verify these conditions before ordering.
Select brake pads whose shape is compatible with the calipers, D1-122 pads, and/or rotors, and whose compound is suitable for sport driving or track use. The Endless, pagid Racing, or Ferodo Racing ranges may be considered after verifying the appropriate part number.
For intensive use, we recommend compatible aviation-grade flexible hoses and high-performance brake fluid that meets the vehicle’s specifications, along with proper bleeding and fluid replacement. This recommendation complements the mounting compatible with the original hydraulic system.
When worn, replace the pads with the part number compatible with your existing rotors. Reusing a rotor for up to three pad replacements is subject to inspection of its condition, its mountings, and the mounting instructions; this number does not constitute a guaranteed service life. Use a new mounting each time you replace the pads.
What are the sizes of the D1-122 tracks for my vehicle? The part number shown measures 350 × 34 mm and mounts to the front axle. The track height, mounting bracket, and cups must also be compatible with the mounting.
Is the product sold in pairs? Yes. It includes a left and a right component for the same axle. The brake shoes are not included.
Do I need to replace my vehicle’s brake pads?Yes. Always install new brake pads with new rotors or new braking surfaces. Use a compound suitable for cast iron and your intended use. For A1-122 sets only. On has modified 991.1 with A1-032 rotors and GT3 pads, use the D1-032 brake tracks. The existing mounting must retain the appropriate caliper spacers.
How do you identify the left and right sides? Girodisc rotors come with a label attached to each rotor: LEFT for the left side and RIGHT for the right side, as viewed from the direction of travel. On a left-hand-drive vehicle, “LEFT” corresponds to the driver’s side and “RIGHT” to the passenger side. Follow these labels and the instructions. On models with curved internal fins, the rolling direction depends on this internal ventilation; the surface grooves alone are not sufficient to determine the side.
How do I break in this mounting on my vehicle? Follow the Girodisc procedure and the brake pad manufacturer’s instructions to build up an even transfer ply. The PDF documents below detail installation and break-in.
We have included two PDF documents below: an instruction manual for installing and breaking in the discs, and an instruction manual for installing new tracks on existing bowls. Consult the document that applies to your specific task before you begin.
