Equal-Length Valved Cat-Back Exhaust System

The Valvetronic Designs Equal-Length Valved Cat-Back exhaust system is engineered to enhance the sound of the BMW F8X M3 and M4's S55 engine, addressing criticisms of excessive rasp and a lack of tonal depth in the stock system. This cat-back system provides a definitive solution for achieving a rich, balanced exhaust note. Constructed from brushed T304 stainless steel, the system features a 2.75-inch equal-length mid-section with an H-pipe design, leading to a 3.5-inch axle-back. The equal-length configuration is key to smoothing the exhaust tone across the rev range while maintaining an aggressive character. Dual-mode operation is achieved through electronic valve control: valves open for maximum volume and performance, while valves closed route gases through a quad-chamber muffler for a quieter, more refined sound suitable for daily driving. Installation is designed as a direct bolt-on process, requiring no cutting or welding. The system is 21.7 lbs lighter than the OEM equivalent and includes Valvetronic Designs Black Single Wall Tips. For optimal sound refinement, the use of high-flow (200 cell) catalytic converters is recommended. It's noted that with free-flow/race downpipes, some 2k RPM rasp may occur during low-RPM shifts. The system fits the 2014-2020 BMW M3 and M4 models.