MAD BMW M3 M4 G8x S58 Axle Back Exhaust

The G8x M3/M4 excels in nearly every aspect compared to its precursor, but the prevailing concern among enthusiasts lies in its sound quality. Similar to its predecessor, the S55 in the F8x, the S58 in the current generation still leaves room for improvement. While the stock sounds are a step up from the previous generation, they still have an excess of raspiness that fails to convey the refined aggression inherent to the brand's signature performance models. MAD remedies this shortcoming with a valved axle back exhaust system that delivers a deeper, more impactful note, and adds a level of amplification beyond the stock version. When paired with the optional single midpipe, it yields an even louder, smoother, and fuller sound. To achieve the desired sound volume and tone befitting the G8x M3/M4, we increased the tubing size to 76mm (from the stock's 70mm), which reduces backpressure and allows a freer flow throughout the system. The larger piping diverges into multiple paths as it app