Benchmarking Airflow

[RedWolf4000]

correct me if im wrong, but isnt it hard to benchmark air flow....?

If you compared a paper filter and K&N, with a low pressure intake, say at idle, or up to 2500rpm on a engine, wouldnt the restrictions match?

But, if you take the car to 7000rpm (lets say this is an SER V-Spec for the sake of high redline) wouldnt the paper start to become restrictive, and the K&N maintain its previous restrcition to a closer degree?

What i mean is, there has to be a bottleneck point for paper filters, so without testing the air flow in many different air pressure levels, how can you get an accurate test?

 

[rpn453]

Not sure if this is going to answer anything, but I'll start rambling anyway and see what happens:

The pressure drop across any filter will increase exponentially as flow increases. So a slightly less restrictive filter at low flow may become substantially less restrictive than others at high flow rates.
You could test air flow at a specific pressure drop, or pressure drop at a specific air flow. This would give you information on the relative restriction of a collection of filters. Without in-depth knowledge or further testing for a certain vehicle (i.e. pressure drop of intake components and total air flow, at various rpm and power levels), the numbers from the test won't be very useful though other than for saying that Filter A has less restriction at X pressure drop or Y flow rate than Filter B.