EBC 13 15 Porsche 911 (991) GT3 3.8L (Cast Iron Rotor Only) Bluestuff Front Brake Pads Effort Square 140 King Street East, Hamilton Effort Trust. Bluestuff NDX is a high friction sport and race material that can be used for aggressive street driving and certain types of track use. The material has had much success on the track with quality aftermarket calipers (Multi piston systems with better release and cooling and larger rotors) and limited success with street based calipers where pad size and caliper drag can challenge any brake material. The biggest advantage of EBC Bluestuff NDX is their bite from cold and progressive brake feel and the ability to bring a car to a complete stop. This has led to the ECE R90 brake safety regulation approval of R90 which is now completed and certificates are being obtained (during July 2011). There are certain older street based caliper systems where even the new Bluestuff will have trouble handling the caliper and slider drag inherent in the systems but this scenario is exactly the same for our competitors. There is NO material that will be PERFECT on the track in all older street based caliper systems. This Part Fits: Year Make Model Submodel 2021 2022 Porsche 718 Boxster 25 Years 2021 2022 Porsche 718 Boxster GTS 4. 0 2020 2023 Porsche 718 Cayman GT4 2023 Porsche 718 Cayman GT4 RS 2021 2023 Porsche 718 Cayman GTS 4. 0 2014 Porsche 911 50th Anniversary Edition 2019 2022 Porsche 911 Carrera 2015 2016 Porsche 911 Carrera 4 GTS 2013 2023 Porsche 911 Carrera 4S 2015 2016 Porsche 911 Carrera GTS 2013 2018,2022 2023 Porsche 911 Carrera S 2014 2016 Porsche 911 GT3 2016 Porsche 911 GT3 RS 2014 2015 Porsche 911 Targa 4S 2014 2018 Porsche 911 Turbo 2014 2018 Porsche 911 Turbo S 2018 Porsche 911 Turbo S Exclusive Series 2016 Porsche Cayman GT4