Filter Test

[Bruce Nunnally]

Diesel truck owner and filter test machine manufacturer test a

variety of diesel truck filters for flow, dust pass through, and

blockage point:

http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

SCOPE:

This report presents the results of an ISO 5011 test of several air filters designed for the GM Duramax Diesel. The test was independently performed under controlled conditions using a $285,000 machine at Testand Corp of Rhode Island (manufacturer of the machine). Arlen Spicer, a GM Duramax Diesel owner/enthusiast organized the test. Ken an employee of Testand offered to perform the tests at no charge. (These tests typically cost approx $1700.00 per filter).  Ken, also a Diesel enthusiast and owner of a Ford Power Stroke Diesel, shared Arlen’s interest in performing an accurate unbiased test of different types and brands of diesel engine air filters. The filters used in the test were purchased retail and donated by Arlen and other individual Duramax Diesel owners. The detailed reports from the test have been compiled and are presented in the following pages. The final pages of this report present the behind the test.

More info is better, so I am glad to see actual test data. Not sure the test supports the author's conclusions that more air flow does not mean more power; it does suggest as some others have argued, that high flow and higher passthrough are related.

[Ranger]

Suspicions confirmed! Thanks Bruce.

[Scotty]

Good Timing

[JasonA]

Great link. I think their statement sums it up well:

"The AC Delco filter test ran for 60 minutes before exceeding the restriction limit while the AMSOIL and K&N tests each ran for 20 and 24 minutes respectively before reaching max restriction. In 60 minutes the AC Filter accumulated 574gms of dirt and passed only 0.4gms. After only 24 minutes the K&N had accumulated 221gms of dirt but passed 7.0gms. Compared to the AC, the K&N “plugged up” nearly 3 times faster, passed 18 times more dirt and captured 37% less dirt."

It should be noted that the AC posted the highest flow restriction of all the filters. It's at this point where we need more data to determine the stock AC filter's effectiveness in the Northstar's airbox. What is the CFM requirement of a stock Northstar engine? What is the CFM capacity of the AC filter that fits our airbox. I think a simple comparison of those two numbers would really add a lot of value to this seemingly never-ending discussion.

[Scotty]

Compared to the AC, the K&N “plugged up” nearly 3 times faster, passed 18 times more dirt and captured 37% less dirt."

Don't you love this? This is exactly what we have been saying all along..

[JasonA]

I do wonder how it could pass 18x more dirt, but capture 37% less, at the same time. Shouldn't their test system be a closed environment? Shouldn't there be a direct (and inverse) relation between dirt passed and dirt captured?

In other words, any dirt it didn't "capture", it would "pass" right? For example, Filter A captures 1 oz. of dirt and passes .5 oz of dirt. Filter B captures .5 oz of dirt and passes 1 oz. Either way, there should be 1.5 oz of dirt total. So in comparison, Filter A passed 50% less dirt, and captured 2x more dirt than Filter B.

See what I'm saying?

Edit: Oh wait -- I re-read what I quoted. In my small example above, I assume there's a constant amount of dirt, but I also assume a constant amount of time. I do remember the test indicating that the AC filter ran almost THREE TIMES longer than the K&N before plugging. Never mind...I answered my own question.

[JasonA]

I just remembered something our Northstar guru said a while ago. He said that a "dirty" air filter means something different to an air filtration engineer than it does to a normal driver. He said that a quality paper filter can be caked with dirt and still provide all the airflow the engine needs. Interestingly, this ISO test confirms just that -- the AC paper filter consumed more dirt than any other filter before a sufficient pressure drop.

Interesting that something an engineer stated months or years ago turns out 100% confirmed by a most unlikely source of information.