GiroDisc Porsche 718 GT4 RS Front 2-Piece Slotted Rotors - Porsche Cayman / Boxster - A1-291
GiroDisc Porsche 718 GT4 RS Front 2-Piece Slotted Rotors - Porsche Cayman / Boxster - A1-291
TAG Motorsports is pleased to offer the GiroDisc Porsche 718 GT4 RS Front 2-Piece Slotted Rotors (part number A1-291) for the Porsche Cayman / Boxster.
These GiroDisc 2-piece rotors are a direct replacement for the Porsche 718 GT4 RS with the factory iron brake system. Weighing in at around 29 lbs per rotor, these fully floating assemblies help shed unsprung weight and rotating mass from the front axle of the vehicle.
The rotor rings are machined from a proprietary casting made of high-carbon iron formulated to GiroDisc’s specifications. This superior metallurgy results in a rotor that holds up better, and the 72 curved vanes act as a centrifugal pump pulling air in through the hub to effectively cool the rotors under hard use. The 2-piece design means a reusable hat which can be attached to new rings (part number D1-291) when they need to be replaced.
All major components including the hats, rotor rings, and drive pins are manufactured in-house at our facility in Bellingham, WA from domestically sourced materials. The hat is made from 6061-T6 aluminum and coated in a black anodize finish. The drive pins are made from a high-strength steel alloy and cadmium-plated for corrosion resistance. All rotors are assembled with spring clips and Belleville washers for race-ready float while also being street-friendly with no noise from loose hardware.
Diameter: 408mm
Thickness: 36mm
Weight: ~29 lbs per rotor assembly
The minimum thickness at which we recommend replacing these rings is 34mm. We also recommend replacing them if a crack leads to the edge of the ring.
GiroDisc part number: A1-291. Sold and priced per pair (one axle).
Fits: Porsche Cayman/Boxster Cayman GT4 RS (Without PCCB).
| SKU | A1-291 |
|---|---|
| Brand | GiroDisc |
| Exhaust Tip Size | 90mm |
PROP65 WARNING

PROP 65 WARNING – Products sold by TMS such as lead acid batteries contain lead, which is known to the
state of California to cause cancer and birth defect or other reproductive harm. Safety Data Sheets for
products sold by TMS are available upon request.
For more information go to:
www.p65warnings.ca.gov/fact-sheets/lead-and-lead-compounds
