N55 CP-E Sport Metallic Catted Downpipe - 135i/335i N55
Higher-flow N55 downpipe includes sport cat
The factory catalytic converter on the 2011+ E82 135i and E90/E92 335i is very restrictive and robs a lot of horsepower and torque but works great for cleaning the exhaust gases. The metallic sport cat in this cp-e downpipe flows better while still stripping out the pollutants with a catalytic element. Allowing more flow makes sense on a track/racing car as it frees up horsepower and removes a potential failure point (a totally clogged cat will kill performance). With less restriction the turbo can spin more freely and with less strain. This not only makes more power and torque but helps the turbos last longer. This version of the cp-e downpipe uses a metallic sport cat instead of the ceramic factory cat. The metallic sport cat is not intended as a replacement for a factory cat and may not meet emissions standards. A check engine light and fault codes may appear. A cat-less downpipe for full race use is also available.
The cp-e Quickpower Downpipe has more well-thought out features and design than any other N55 downpipe we have seen. It's a full 5" stainless steel body - quite a bit larger than others. The end pieces on either side are a cast stainless steel instead of multiple tubes welded together. Casting the ends results in smoother flow and less chance of cracks and leaks from bad welds. cp-e used the latest CAD technology to digitize the stock downpipe and replicate its layout and dimensions in their new design. Flanges and fixture points are laser cut and CNC machined and TIG welded to ensure precise fitment on every part. Other high volume and cheaper downpipes do not have the level of precision we have seen on the cp-e. This downpipe is used with the factory gaskets, hardware, and sensor bungs. 304 stainless steel is used without and cp-e has a lifetime warranty on this part. Made in the USA.
This version with metallic sport cats is excellent for race/track cars that want to the extra power and reliability of donwpipes 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 downpipes, with or without a catalytic converter.
* - Notice of Fault Codes/Check Engine Light - Using any Racing downpipe could result in a check engine light and fault codes, even with metallic cats. Although we have heard of cases where no check engine light appeared, these Racing downpipes are not designed to meet emissions testing and regulations. Race software that is specific to your mods is strongly advised to better adapt your car to a racing environment, keep the fault codes from appearing, optimize power gains, and improve general drivability. Our Epic Motorsports Race software is strongly encouraged to meet all of your tuning goals.
Notice of Emissions Non-Compliance. Removing, disabling, or altering emissions equipment on a pollution-controlled road vehicle is illegal. Installing devices or software that trick, disable, or modify emissions controls and monitors on a pollution-controlled road vehicle is also illegal. This product is sold only for racing, competition, track, hobby, or other off-road use. It's use is prohibited in any motor vehicle that is subject to emissions inspection or control. Legal only for racing vehicles that may never be used, or registered or licensed for use, upon a public highway. Some suppliers will not ship to certain states, requiring extra delivery time. We will advise you of any delays.
E82 / E88 (08-13) > 135i
E82 / E88 (08-13) > 135is
E90 / E91 / E92 / E93 (06-13) > 335i