Milltek Axle Back Secondary Catalyst Bypass for the BMW G8X M3 and M4 (S58). Mandrel-bent T304L stainless steel construction with a non-resonated 102mm single mid-pipe and X-pipe configuration, engineered to remove secondary catalyst restrictions post-turbocharger for improved turbo efficiency and mid-range response. Direct bolt-on to either the OE axle-back or the Milltek axle-back with no modification required.
Key Features:
Mandrel-bent T304L stainless steel with hand-finished welds
102mm bore non-resonated X-pipe design, optimized for track and closed-course use
Uses OE mounting points and hangers - no modification needed
TUV tested for durability
Fits: 2021+ BMW M3 & M4 Competition (G80/G82, S58 engine)
