The BMW G87 M2’s S58 engine has no shortage of performance potential, but the exhaust system still plays an important role in how effectively that power reaches the road. The MAD 4" FATBOY Single Midpipe is designed to reduce unnecessary restriction through the center section while giving the M2 a deeper, more aggressive exhaust character.

Built specifically for the G87 M2, the FATBOY uses a full-length single 4" center section and maintains a minimum 3" diameter throughout the system. The large-diameter design prioritizes exhaust flow while helping produce a smoother, fuller tone compared with the factory midpipe.

A Full-Length 4" Single Center Section

The defining feature of the FATBOY is its large single-pipe configuration. Rather than splitting the exhaust flow through smaller passages, the midpipe uses a full-length 4" center section to provide a direct, high-flow path through the middle of the exhaust system.

The tubing maintains at least a 3" diameter throughout, helping minimize restrictions and keep exhaust gases moving efficiently. For S58-powered M2s running additional performance modifications, this provides a strong foundation for a less restrictive exhaust setup.

Deeper Sound With Less Rasp

The FATBOY isn't only about diameter. Its design is also intended to change the character of the G87 M2's exhaust note.

The result is a deeper, smoother, and more aggressive sound, while reducing the rasp that can become more noticeable when aftermarket downpipes are installed. The larger single midpipe helps give the S58 a fuller exhaust note without simply making the system louder for the sake of being louder.

It works with both factory and aftermarket downpipes, making it suitable for a range of G87 M2 configurations.

Designed Around Your Existing Exhaust Setup

The MAD 4" FATBOY Single Midpipe is designed to work with a variety of axle-back configurations. The kit includes both 3" and 2.75" reducer couplers, allowing the larger 4" midpipe to connect with factory or aftermarket axle-back systems where required.

This gives owners more flexibility when building their exhaust system rather than requiring a complete exhaust replacement just to accommodate the larger midpipe.

Factory Cut Point and Clamp System

Installation is designed around the factory exhaust cut point and clamp system, allowing the midpipe to be installed without permanently modifying the vehicle.

This also means the installation is reversible, which is useful for owners who may want to return the car to its original configuration later.

Because the FATBOY uses a substantially larger center section than the factory component, MAD includes an upgraded brace specifically designed to provide the additional clearance required for proper installation.

Built for the BMW G87 M2

The FATBOY Single Midpipe was developed specifically around the S58-powered G87 M2 rather than being a universal midpipe adapted to the platform.

With its combination of large-diameter tubing, vehicle-specific fitment, reducer couplers, and upgraded clearance brace, the kit provides the components needed to integrate the 4" center section into the M2's existing exhaust layout.

Key Features

• Full-length 4" single center section
• Minimum 3" diameter throughout
• High-flow design intended to reduce exhaust restriction
• Deeper and more aggressive exhaust tone
• Reduced rasp compared with more restrictive configurations
• Compatible with stock and aftermarket downpipes
• Includes 3" and 2.75" reducer couplers
• Compatible with factory or aftermarket axle-back systems
• Uses the factory cut point and clamp system
• Reversible installation
• Includes upgraded brace for proper clearance around the larger midpipe
• Designed specifically for the BMW G87 M2 with the S58 engine

Upgrade the Center Section of Your G87 M2

For G87 M2 owners looking to make a meaningful change to both exhaust flow and sound, the MAD 4" FATBOY Single Midpipe takes a straightforward approach: increase the diameter, simplify the center section, and give the S58 more room to move exhaust gases.

Whether the car retains its factory downpipes or has already been upgraded with aftermarket units, the FATBOY provides a high-flow midpipe solution with a deeper exhaust note and a purpose-built fit for the G87 M2.

Shop the MAD BMW S58 4" FATBOY Single Midpipe for G87 M2: https://mad-us.com/mad-bmw-s58-4-fat-boy-single-midpipe-m2-g87/