The Downpipe Kit fits to: BMW 135i E82/E88 BMW 335(x)i E90/E91/E92/E93, E84 X1 n55
On my car for 1.5 year.. going back to stock.
From Wagner:
The Wagner Tuning N55 downpipes flow better than stock and other designs thanks to CAD engineering, oversized stainless steel piping, and OE-style connectors. These are some of the best fitting E82/E90/E92 downpipes we have seen to date. Reducing backpressure makes the turbo more efficient and longer-lasting while minimizing the potential for fault codes and limp modes when on track. With less backpressure the turbo can spool up faster and be more responsive - more boost is available sooner and with less lag.
This version with metallic sport cats is excellent for race/track cars that want to the extra power and reliability of downpipes but must retain cats for rules compliance. With more racing series moving to catted exhaust systems these high-flow sport cats are exactly what a tracked N55 needs. We strongly advise race-specific software* for all non-factory down pipes, with or without a catalytic converter. $400