Best Induction Kit / Set up

[jondee86]

comparing the airflow through one square inch of media is meaningless and
misleading. With the exception of a flat panel foam filter (if such a thing
exists) all air filters use some type of pleating or folding of the filter media.
This allows the active surface area of the filter to be many times the area
of the filter face area.

There are a range of factors that need to be considered when comparing
engine intake air filters. These include flow rate, initial resistance to airflow,
dirt holding capacity, particle capture efficiency, service life and how the
performance of the filter changes during its service life.

Research shows that the particle sizes that cause the most wear in engines
are in the 10-20 micron range. So it is critical that the filter have a high
efficiency in capturing particles in this range. Smaller particles tend to pass
straight through the engine and larger particles are more easily captured.

Testing for filter efficiency on capturing particles in the 10-20 micron range
can only be carried out in a properly equipped laboratory with sophisticated
measuring instruments and a supply of an ASTM standard test dust. Any
claims made by filter manufacturers that cannot be backed up by
independent laboratory testing should be taken with a grain of salt.

You could make a filter out of scotchbrite pad, oil it and use it on your off-
road racer, and it would collect a lot of dirt. It would have low resistance
which gave you better airflow for more performance and you could wash it
out and re-use it many times. Win all round you say But after a couple of
races your engine would be down on power... losing compression... oil very
dirty

Your engine just got 100,000 miles of wear in 500 miles of use because your
filter only captured the big lumps and a bit of fine dust on the oiled strands.
The wear causing particles passed straight through.

At the other end of the scale you could make a filter out of six layers of
used Covid surgical face masks. It would capture all the wear causing
particles but you would need a huge amount of filter surface area and the
filter would reduce the airflow to your engine as it loaded up with dirt.

What I am saying is that an automotive air filter has to meet a number of
goals. Low resistance and high efficiency do not go hand in hand.



The high efficiency HEPA filters used in the airconditioning systems for
operating theatres will usually have a low efficiency panel filter in front to
trap the largest particles, a second high efficiency filter to capture most of
the dust load, and then the HEPA filter only has to capture the very finest
micron size particles.

Most people looking for a filter upgrade will use one that fits in the available
space, looks good and is a nice colour. I chose ITG for my ITB's, Apexi for
single throttle and used oiled foam on my dirt bikes.

Cheers... jondee86

PS: Sunday morning under Covid lockdown... and since I once worked
selling air filters you get some rambling