Direct-fit downpipe kit for pre-06/2013 BMW F-series with N55 engines: M135i (F20/F21), 335i (F30/F31/F34), 435i (F32/F33). Replaces OEM part 18328603875.
Made from 1.4301 (SS304) stainless steel - corrosion-resistant and built for fast-road or track-day use
Includes 200cpi catalytic converter and 105mm flange - optimised flow without over-scavenging
Reduces turbo back pressure for stronger mid-range torque and lower exhaust gas temperatures
No cutting, no welding, no guesswork - bolt-on fitment with OEM-style mounting points.
