These are the very same brake pads we used on the 034Motorsport Audi S3 for track days. They are extremely well-suited for the stock calipers, and we highly recommend using them in conjunction with the Cobalt XR2 Audi S3 & MkVII Golf R Track Rear Brake Pad Set.
Cobalt XR1 is an extremely high torque material with a rapid, yet controlled, transition from an aggressive initial bite to a medium-high, linear rising torque curve. Excellent friction stability and consistency coupled with very good modulation, threshold control and release characteristics over the industry's broadest operating temperature range. The XR1 material has unmatched disc life and finish versus any other competing friction material of comparable torque.
The XR1 compound effectively bridges the gap between "sprint" and "endurance" materials, providing an optimal balance of ultimate high torque and very good wear rates. Equally well-suited for a wide range of platforms, including those with active aerodynamic profiles as well as limited downforce applications, and/or ABS-equipped as well as non-ABS vehicles, due to the direct line pressure to generated torque relationship.
As with all Cobalt Friction XR-Series Carbon-Ceramic friction materials, the XR1 does not require any bedding¹, and will deliver 100% consistent performance within 1-2 laps, while still maintaining a superior, uniform disc finish.
¹ Full torque potential of all Cobalt materials will be realized within 1-2 laps. However, proper on-vehicle or inertia-dyno bedding will yield an 8-10% improvement in wear rates.