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      01-06-2013, 02:34 PM   #44

Drives: E92 320D M-sport
Join Date: Apr 2008
Location: belgium

Posts: 725
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Originally Posted by jsmonet View Post
bmw engineered the factory intake to function responsibly, efficiently, at 8lb of boost. even the least aggressive tunes turn that up to 12+, and most people are running something between 14 and 17lb. granted this isn't a huge turbo so you're not pulling world-shattering cfm, but there's a chance to outrun the efficiency of the stock filter in that scenario..
Oh bugger - we diesel owners then must have a major problem as we have these boost levels on box standard engines:

N47 (my engine): 22.5 psi (I reckon my remapped car is at 30psi+)
M57 (the 335d): 28 psi (I don't want to know at what level a tuned 550lbsft 335d is..)
N47 twin turbo (the 07 onwards model with really two turbo's): 29 psi

I can't read my actual max. boost pressures, as the pressure sensor I have only goes to 255 kPa = 37 PSI = 22.5 boost + 14.7 atmospheric.