The results don't seem to debunk a myth - I though it had always been known that they filtered less to have a less restrictive flow (which they found) and is the reason high flow filters are used, or no filter at all for some drag cars. What I find odd is that the methodology is dodgy, their calculations are off, and I'm a stickler for spelling in would-be scientific research.
In their dust accumulation calculations - AC Delco ran for 60 minutes, not 59, not 61 -> it was fed 9.8 grams per minute = 588 grams total, with an undisclosed mix of particle sizes ("specific distribution of particle sizes ranging from less than 2.5 microns to greater than 80 microns (see table below)." <- no table shows particle distribution)
So 588 grams got fed to the AC Delco - 574 got caught, 0.4 was passed through... so where's the other 13.6 grams?
The K&N lasted 24 minutes, so it was fed 235.2 grams, it caught 221, 7.0 was passed through... where's the other 7.2 grams?
The dirt passing through each filter was captured in the test rigs "Post Filter" - was a new filter used each time, what type of filter is it, is it a perfect filter (impossible), are the missing grams this "post-filter's" error rate - why is the error rate not constant between tests, was the filter weighed and reused - if the test was based on inches of water air restriction and the same post-filter was used, how was the filter cleaned - was it not cleaned and therefore added progressive restriction to the assembly - in what order were the filters tested... etc etc etc.
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