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      03-14-2011, 12:54 PM   #26
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Drives: Krooked Sk8board
Join Date: Feb 2008
Location: Pasadena, Ca

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hey guys i wanna talk bout exhaust and gains for the N55.

As some of you may know i've been prep'n to dyno
Injen's intake and in doing so I found some interesting finds in my
exhaust + oem intake from my recent pulls.

To fill you in, this is the process I've taken in the past week or so.
-received new injen intake - test driven no dyno.
-then removed intake, took e90 to dealer for 15k service (scheduled service)
-E90 was reprogrammed according to mandatory update.
-drove a few days with stock intake, for adaption to settle with bimmer
-Dyno'd with vanguard exhaust and stock intake.
-removed stock intake, installed injen intake -
-been driving around a few days with injen intake, letting the adaption feature settle before dyno.

I got the numbers for the dyno with the exhaust + OEM intake.
and look'n at these numbers compared to my baseline numbers
it show some loss in power.

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I lost a few whp, torque number seems to be fine but pass 5800k
you'll see the drop up top. There were no gains.

Looking at these numbers lead me to think -
that the oem exhaust really does not have a restriction.
Unlike the N54 or the N55 xi where you'll have cats the only
restriction the n55 does have are the double cats on the DP.

does the N55 xi have 1 or 2 cats on the DP?

Honestly the exhaust adds great sound but i see no gains.
anyone else do a dyno with their aftermarket exhaust?
if the findings are similar, I would make the conclusion
that gett'n the Catless DP before an exhaust would make more
sense. I have DP's and the procede next up to bat for my N55.
I like to see if any gains would come out of DP's and a after market
exhaust for our N55.

let's discuss.
2011 335 E90 MTECH 6MT KW V3 INJEN Intake Berk 4" DP Vanguard V2 exhaust Procede V5 Stoptech BBK RPI Scoops Karbonwerk CSL Trunk LUX H8 19" BBS LM 18" BBS GT4