• cp-e N55 Downpipe preview with pictures, dyno graphs, and video

      A N55 355i Owner was kind enough to stop by last week for some testing of a prototype unit of the cp-e N55 downpipe. The day went perfectly for such testing. The part was designed and built completely from computer data, without any fabrication on the car. The part was already ready without being in any vehicle prior. This was a true testament to doing CAD development in the most effecient way possible. Fitment was dead on, lining up with brackets, flanges and sensors flawlessly. Performance was to our satisfaction as well. Dyno charts below.

      Some basic overviews:

      - Full 304 Stainless construction
      - CAM/CAD designed
      - ONLY 3 WELDS - great durability and precision of the part (precision=OEM like fitment)
      - CNC machined v-band flange and surfaces
      - Casting allows for smooth flow and transitions
      - 5" Diameter - great flow and allows for a large catalyst
      - 5" catalyst will provide high flow and effectiveness for those who seek compliance
      - Included additional O2 bung for Wideband and a bung for an EGT probe - cast in and tapped.

      All our parts, including this one when it comes out, carry a lifetime warranty.

      Enough talk!






      Dyno testing showed impressive gains at various sections of the power curve - the car felt a lot stronger through the RPMs. The graphs speak for themselves. As everyone knows - look beyond just the peak numbers.

      Stock baseline vs cp-e DP
      +17whp +21wtq - Great gains for just bolting on a part




      JB 4 Stage 2 Map 1 Baseline vs same tune with DP
      +10whp. The flow capability of the DP really shows with a bump of 25wtq in the mid range
      This is gains ON TOP of what are already gains over Stock - we are optimizing the performance of a bump in boost and a tune that the JB4 packs in.





      JB4 Stage 2 Map 2 vs Stock tune Baseline
      Massive gains over stock with a DP and tune. ~35whp ~50wtq in the mid range.













      And a clip





      Please feel free to ask questions - Ill try my best to tend to the thread!

      Thank you all!
      This article was originally published in forum thread: cp-e N55 Downpipe preview started by www.cp-e.com View original post
      Comments 45 Comments
      1. turugara's Avatar
        turugara -
        Exhaust Note from exterior with Downpipe


      1. maxnix's Avatar
        maxnix -
        Sure would like to see a flow comparison between the CP-E 5" catalytic equipped and the stock N55 catalyst. Would be surprised if CP-E published such.
      1. maxnix's Avatar
        maxnix -
        I wonder if this project died?
      1. maxnix's Avatar
        maxnix -
        Click here to enlarge Originally Posted by maxnix Click here to enlarge
        I wonder if this project died?
        Nope, $600 on the website.

        "Spun Metal" catalyst for $200 more. Pray tell, what is that? I know about ceramic.......
      1. maxnix's Avatar
        maxnix -
        Well, called CP-e and they said spun catalyst will pass emissions. Might have to verify that soon.