MAD BMW S58 4" Fat Boy Single Midpipe M3 M4 G80 G82 Good GO or custom modes

or custom modes

requiring no cutting or welding

delivering superior cooling efficiency compared to the stock cooler and keeping your transmission cool even in the most demanding driving conditions

Bolt-On Installation: No need to be a master mechanic—our kit includes all the hardware you need for a straightforward installation

MAD BMW S58 4" Fat Boy Single Midpipe M3 M4 G80 G82 Good GO or custom modesG8X M3 M4 4" FATBOY Midpipe Flow Is Everything Flow is everything and the new MAD 4" FATBOY Midpipe delivers exactly that. Designed specifically for the G8X M3 M4 platform, this midpipe is built to maximize performance and sound without compromise. Featuring a full length single 4" center section and a minimum pipe diameter of 3" throughout, the FATBOY Midpipe is all about maintaining optimal exhaust flow from front to back. Expect a deeper, more