Grail BMW M3/M4 OPF Back Exhaust System (G80/G81/G82/G83)

The Grail stainless steel upgraded exhaust system for the BMW G80, G81, G82 and G83 M3 and M4 vehicles produces an incredible sound. The Grail system transforms the driving experience of the S58-powered M3 and M4. Gone is the strangled rasp of the factory system – not to mention the sizeable weight saving! This exhaust system is an OPF-back, retaining the car’s primary and secondary catalytic converters in place, as well as the OPF on UK/EU cars. If you have a US market vehicle, this system works great as an axle-back, by removing the restrictive resonator and replacing the flawed OEM backbox.The use of highly effective silencers enables maximum volume and wonderful engine sound. When the valves are closed, the exhaust gases flow through the rear backbox to allow the system to remain quiet for daily driving. When the valves are open, the rear backbox is completely bypassed for maximum noise! The rear silencer is also angled upwards so you don’t see the ugly ‘udder’ that you get with the factory system.SPECIFICATION- Hand-crafted in Germany from high-quality L304 stainless steel- Significant weight savings- Retains OEM BMW valves- Massively improved sound with the flap open and closed- 100% handmade using the TIG welding processCOMPATIBILITY- BMW G80 M3 Saloon (2021+)- BMW G80 M3 Competition Saloon (2021+)- BMW G81 M3 Touring (2023+)- BMW G81 M3 Competition Touring (2023+)- BMW G82 M4 Coupe (2021+)- BMW G82 M4 Competition Coupe (2021+)- BMW G83 M4 Convertible (2021+)- BMW G83 M4 Competition Convertible (2021+)