13-19 BMW 135i 335i 435i M2 N55 Catless Downpipe F32/F33/F36/F22/F23

Circuit Werks catless downpipe for the N55 BMW. 

Back pressure is significantly reduced by eliminating the restrictive catalytic converter in the factory downpipe with our catless which results in faster spool, an increase in power  and more aggressive exhaust note.

All M135i & 335i models produced up to 07/13 require the 3.5″ version of this downpipe that we offer as well.                                                                                                         The 3.5" uses a Pneumatic Wastegate 

M135 and 335i models produced after 07/13 require the 4″ model of this downpipe.                                          

The 4" uses an Electronic Wastegate

All M235 and 435i models require the 4″ version of this downpipe. Please confirm by looking at your Turbo Wastegate. It is located on the lower passenger side of the engine next to the Turbo. 

• Made from hand crafted, TIG welded stainless steel.
• Smooth radius bends to decrease turbulence and increase flow.
  
• CNC stainless steel flanges.
• Gains from 20-25hp with tune.