Slip-on system (S-PO/TI/15) for GT3 RS / Speedster OPF model must be mandatory combined with:- Evolution Header Set (E-PO/T/6)- Tail pipe set TP-T/S/19. When combining the slip-on system with optional carbon fibre diffuser DI-PO/CA/7/G, you must use tail pipe set TP-T/S/17.- An additional original Porsche stock bracket (Porsche p/n: 99111147391) is required for mounting the Akrapovič exhaust system. Please read the instructions carefully before the start of the installation.This Slip-On Race system (S-PO/TI/8) must be upgraded into a full Akrapovič Evolution Race Line exhaust system by combining it with the Evolution Header Set (E-PO/T/6) with side mufflers and valves, which is designed to supplement the performance at higher revs. With complex parts cast in Akrapovič’s own titanium foundry, the expertise used in this system, and the coating finish, the system demonstrates the highest standard of workmanship and technology. Incorporating 100 cpsi sports catalytic convertors in the exhaust manifold and side mufflers, the Evolution Race Line utilizes integrated catalytic convertors and the functionality of the exhaust valves to deliver a complete workout for the senses. The system offers a near-perfect power curve, along with an altered torque distribution, all designed to continually deliver performance as the revs rise. The use of lightweight materials results in big weight savings, and the addition of the Evolution Race Line will have the car performing like a true cup racer, with a powerful racing sound that resonates with every push of the accelerator pedal, producing a deep, pure racing growl to match the performance.The mandatory tail pipe set TP-T/S/19 needs to be ordered separately. When combining the slip-on system with optional carbon fibre diffuser DI-PO/CA/7/G, you must use tail pipe set TP-T/S/17.An additional original Porsche stock bracket (Porsche p/n: 99111147391) is required for mounting the Akrapovič exhaust system. Please read the instructions carefully before the start of the installation.When installing Akrapovič aftermarket optional link pipes with sports catalytic converters or without catalytic converters, which are developed for use on closed tracks only, remapping the ECU is mandatory. When installing Akrapovič aftermarket exhaust system that was developed for use on closed tracks, we recommend remapping the ECU in order to prevent potential »check engine light« warning signals.THIS PRODUCT DOES NOT MEET EMISSION COMPLIANCE REQUIREMENTS FOR STREET OR HIGHWAY USE.