From digest.v4.n835 Fri Jul 12 14:48:04 1996
From: bbowden_at_hach.com (Brian Bowden)
Date: Fri, 12 Jul 96 11:36 MST
Subject: K&N Airfilters
>Has anyone truly
>believed that they have gotten significant performance enhancement from
>any of the aftermarket filters such as the K&N?
>Your comments are appreciated as I will be changing the air filter in my
>1991 Model 535i in the near future.
Well, you asked. I recently installed the K&N replacement filter in my 1994
325is. At the same time, I removed the air funnel thing inside the stock
airbox based on previous information that this is also a restriction on airflow.
Observations: More noticeable intake noise, car appeared to breathe better
and pull stronger. I noticed significant improvement in driveability with
the AC on, car does not seem to bog down as much. Car also does not bog
down as much on hard acceleration from a stop.
Testing: As an advocate of the 2nd gear acceleration test, after
installation I promptly performed this test fully expecting to register a
numerical result reflecting the improvement that my observations were
telling me where there-well the numbers showed only a 0.03 sec improvement,
after temperature correction. An insignificant improvement.
My opinion: My results show that any improvements in flow are very minor
with the standard filter replacement on a 325is. So, I don't necessarily
believe this is a performance upgrade that is meaningful. However, I'll
never have to replace the filter again!
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