MAD BMW S55 3.5" Fat Boy Downpipes M2C M3 M4 W/ Flex Section Silver Ceramic Coated?:Yes Stock air filters are replaced

Stock air filters are replaced with 77% larger Dinan conical air filters for optimum flow

ETA: Dec 5th 2025

N55 pneumatic wastegate (PWG):

Our bar & plate core is also much more durable than the OEM tube and fin core

MAD BMW S55 3.5" Fat Boy Downpipes M2C M3 M4 W/ Flex Section Silver Ceramic Coated?:Yes Stock air filters are replacedWe are proud to introduce the MAD S55 Fat Boy 3. 5" Downpipes. These are the largest BMW S55 M2 M3 M4 downpipes on the market. Upgrade from the stock S55 downpipes to the MAD 3. 5" S55 catless downpipes for maximum airflow, power, and sound! Upgrade to the MAD BMW 3. 5" S55 downpipes to eliminate the backpressure caused by your stock catalytic converters. By upgrading to our downpipes, your turbos can now spool faster and achieve maximum power. As a