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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.

The stock tune looks sloppy, the tuned run is just as bad. I simply don't under what BMW did with this engine. For reference I dynoed 242 bone stock on this very same dyno and ht 350 with a dci/meth and no other mods. For this engine to barely crack 270, that is just disappointing. Hopefully a better tune will smooth things out and try to squeeze out some more power.

Yeah it will take some time to really figure out how to tweak this engine some..not to mention most of the people who own a N55 are all leases these days, and those who finance are barely affording one.

The people with the big money seem to have these just as daily drivers..no one is willing to drop the money for R&D..

Yeah it will take some time to really figure out how to tweak this engine some..not to mention most of the people who own a N55 are all leases these days, and those who finance are barely affording one.

It's bad, the VAST majority are leases. We won't see this picking up steam until people buy them second hand and want to mod. Kind of a shame what is happening to the BMW tuning industry with people just renting the brand name instead of actually having a car.

... BMW tuning industry with people just renting the brand name instead of actually having a car.

I take offense to that statement... I'm actually financing mine, and still managing to do some Mods... Matt can attest to that... Although most of my mods are 'One Off' projects, that will probably never pick up steam

Originally Posted by Sticky

until people buy them second hand and want to mod

And once I own the car outright, I will go full steam on some of the more, radical mods, like hopefully a turbo upgrade... But that's a couple years off (2013)

CP-E great news for the 335 owners... Now get cracking on a pipe for the X5... But make it a hi-flo catted variety...

I take offense to that statement... I'm actually financing mine, and still managing to do some Mods... Matt can attest to that... Although most of my mods are 'One Off' projects, that will probably never pick up steam

Absolutely, I understand why you would take offense. I am speaking generally which is accurate, obviously the crowd here is the exception.

Hey I also own my 335d and paying for it. NO!! Im not rich or wealthy I just invested my inheritance correctly in housing and getting dividends, a question for you guys is there going to be any other MODS for the DIESEl besides JB piggyback, I am a willing GUINEA PIG in Puerto Rico willing to participate!!

I too am an outright owner. However, warranty retention is still an issue with the car so young. Hence, I am concentrating on "passive" modifications that help the car runn cooler and breathe better. Ultimately, I am thinking a larger turbo will be what is required for serious gains. However, I want to retain street manners, so not going to jump off the edge.