3-Series (E21, E30)Chat relating to the BMW 3-Series from 1975-1983 and 1984-1991 line. Specific models: BMW 315, BMW 316, BMW 318, BMW 318i, BMW 320/4, BMW 320i, BMW 320/6, BMW 323i, BMW 320i. E30 Family models include: BMW 325e, BMW 325i, BMW 325is, BMW 325ix.
Hey all. I swapped the old stock style air filter in my car for a nice, high flow K&N and noticed the difference immediately. The thing I am wondering is if any difference would be noticed if I were to remove the 'snorkel' from inside the air box that is attached to the Mass Air Meter. There is only a gap of a couple of cm's between the tip of the snorkel and the wall of the airbox. Would pulling that thing out of there be less restricting for the airflow into the MAFM, or is it there to smooth the flow into the MAFM?
Sounds like it might be best to leave it in there, uniform flow is better than marginally higher and turbulent!
No no no no no no no no. You're thinking of laminar flow through a pipe, which is true, with laminar flow, you have a thinner boundary layer and faster travel through the pipe, but that does not apply to an engine intake because you want turbulence, so you have a rough intake runner in the head itself with a lip to act as a vortex generator. For a car intake, you want greatest flow through the intake possible, because the intake is running on vacuum and small changes make a big difference when your highest pressure is ambient only (14.7psi worth of flow if you have a full vacuum, which isn't much really and that's at sealevel) because you really have a massive pressure cap, so you can't cram to get your flow, you have to go bigger and less restricted, turbulence doesn't cause much damage to a low pressure flow in a fat 3" pipe.
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