cp-e N55 QKspl™ 5″ Cast Stainless Downpipe BMW (e82) 1-Series 2008+

cp-e (Custom Performance Engineering)

$ 698.99

Excessive back pressure in the exhaust system can cause delayed turbocharger response. Eliminating restrictions in the exhaust system is key to increasing engine efficiency and power.


  • CAM/CAD Engineering
  • CNC Machined Castings
  • Full 304 Stainless construction
  • Perfect Fit
  • Cast bellmouth for a smooth transition
  • TIG welded
  • Available with custom cp-e™ designed High Flow Catalytic converter
  • Standard Wideband O2 bung included
  • EGT bung included
  • Made in the USA
  • Lifetime Warranty

The cp-e™ 5″ cast stainless downpipe has been designed specifically for the N55 engines to minimize back pressure in the collector and optimize exhaust flow.

The CAD designed castings on both ends of the downpipe are designed to work with a 5” diameter center section. This will be available with and with out a catalyst. The entire system (castings and tube) is made from 304 stainless steel.

We used our FARO CMM (Faro Technologies Coordinate Measuring Machine) to design the downpipe. With our CMM we were able to digitize the model and keep within .010” of the stock flanges and mounting points. In addition to the downpipe being designed in CAD, our fixtures for the manufacturing of the downpipe were also designed in CAD. The fixtures were then laser cut and CNC machined to assure precise fitment, every time.

This extensive process is nearly impossible to replicate with a hand fabricated part.

The 5″ downpipe may be installed without any permanent modifications, and is available with or without a cp-e™ custom designed high-flow catalytic converter.

While this may not trip a Check Engine Light, we cannot guarantee that all of the codes will be in the “ready” state.

This item fits the following BMWs with the N55 engine:
2011-2013 E82 BMW 135i 135is
2011 E90 BMW 335i 335xi 335i xDrive - Sedan
2011-2013 E92 BMW 335i 335xi 335i xDrive - Coupe
2011-2013 E93 BMW 335i - Convertible
Left Hand Drive ONLY

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