MAD G8X Full Exhaust

MAD SKU: MAD-5069-Brushed +MAD-5048

$2,128.00 $2,598.00 Save $470

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The G8x M3/M4 offers improvements in various areas compared to its predecessor, but some enthusiasts are concerned about its sound quality. MAD addresses this with a valved axle-back exhaust system, enhancing the car's sound with a deeper, more impactful note. This system, when combined with the optional single midpipe, produces an even louder, smoother, and fuller sound.

To achieve the desired sound, we increased the tubing size to 76mm, reducing backpressure for improved flow. The exhaust system's design allows for noise reduction when valves are closed and maximum enjoyment with open valves during high-load conditions. This balance caters to a range of preferences.

MAD's G8x M3/M4 exhaust is crafted from high-quality stainless steel, TIG welded for superior appearance, and brush-finished for a polished look. The quad 4.5-inch exhaust tips seamlessly integrate into the factory cut-outs, offering an OEM+ appearance with added attitude.


  • Connects to Factory Midpipe (Cutting required) or MAD Single Midpipe (No Cutting required)

  • Maximum gains of +17 HP and 15 lb-ft of torque  Full Exhaust   (Muffler only +5 whp + 5 wtq)

  • Pleasingly louder, sportier sound

  • Drone abatement technologies reduce cabin resonance

  • 4.5-inch (114mm) tips Options  (Carbon, Brushed, Black)

  • Larger diameter piping for increased flow (76mm vs. 70mm)

  • 7-pounds lighter than the stock axle back (Stock: 44-pounds vs. MAD: 37-pounds). Full system is 31 lbs lighter!

  • Reuses stock exhaust valve actuators, and the operation of exhaust valve is unchanged so the exhaust tone can be adjusted via the M-drive settings

  • Includes extended valve harness 

  • Computer-controlled exhaust valves are retained and limit noise during low-speed driving, and open fully during high-load conditions

  • 100% 304 Stainless Steel construction

  • Factory-like fitment with included mounting hardware