


Product Details
About this part
Free Shipping
G8X 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 aggressive tone with significantly less rasp, even when paired with aftermarket downpipes. Whether you're pushing the limits on track or just want that perfect balance of refined aggression on the street, the FATBOY Midpipe transforms your G8X's character in all the right ways.
Key Features:
-
Full-length single 4" center section
-
Minimum 3" diameter throughout for consistent flow
-
Deeper, more refined exhaust note with reduced rasp
-
Perfect pairing with aftermarket or stock downpipes
-
Includes 3" and 2.75" reducer couplers to connect to 3'' aftermarket axle-backs such as ours or factory axle-back systems
-
Utilizes Oem Cut location and clamp design for easy installation and reversibility
Fitment:
- 2021+ BMW G80 M3
- 2021+ BMW G82 M4
Fitment
Not sure it fits? Contact us with your car's year, model and VIN and we'll help you confirm before you order.
If a part doesn't fit as expected, contact us and we'll work with you to resolve it.
Majority of products have a fitment section in the product description or within the title.
Returns
- Unused, uninstalled parts can be returned or exchanged within 30 days of the order date.
- To start a return: Contact us first, don't use Return to Sender.
- Returns can have up to a 20% restocking fee.
- Built-to-order and special-order items can't be returned or cancelled once production begins.
Shipping
- Orders are processed 7 days a week to ensure your product ships as quickly as possible.
- Inspect parts within 10 days of delivery, and reach out regarding any damage or missing pieces.
See our Tariff Policy
Warranty
- All parts retain the manufacturer's warranty.
- Warranty claims are subject to the manufacturer's approval.