Air Flow Tests on Napa Gold, Amsoil,Jackson Racing,K&N, and Baldwin

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This is a direct link to our Air flow tests on the above filters provided by AnthonyS. I want to thank him for his time and donation of this info to our site.

Any comments or discussions on his tests are reserved for this link. Thanks.
Bob

Air Flow Tests

[ July 27, 2003, 01:59 PM: Message edited by: BOBISTHEOILGUY ]
 
So what does this mean for all the K&N and Amsoil promoters out there? Are manufacturers tests "rigged" to get the results they want? Everybody cant have the "best" filter in all categories! Looks like this test was almost as scientific as the rest, yet it showed very different results than the manufacturers would want you to beleive!
 
quote:

Originally posted by Jim:
I want a filter made from the same material the "after filter" was made from.

Not any problem Jim as it was the media from an OTC Fram filter.
 
I will say like many non-scientific, non-standardized "flow" tests the results can vary widely depending on the set-up.

I saw this awhile back on the web, not sure of the sudden posting, Bob?

I won't argue too much with the flow numbers, as he stated, not a huge difference between the bunch. I also agree the oiled foam is a bit of a hassle.

I will argue a bit with a series test - IOW, 1 or 2 of the filters could have hit a lot more dirt than the others. Not standardized at all.

I will argue with his "dirt amount verification". How much of that is dirt, how much is oil...in other words, would an oiled filter look worse because the oil hits his test paper and causes more dirt to stick, vs. a dry filter just allowing the same dust to pass, then pass his filter paper as well? I just have not seen elevated numbers in the oil of my cars with Amsoil oil filters - that would correspond with the dark patch.

Lastly - I wonder on all the filters - just how much of that dirt went around the filter via lousy seal vs. through the filter?
 
I'd like to see the surface area of the various air filters listed.

I've noticed that the cotton gauze type filters, with their two layers of support screen, have a very thick element. As such, they just can't pack as many pleats into a filter as a "paper" air filter.

Having looked at both types of air filters for my car, I noticed that the "paper" air filters have about 2-3X the surface area as the cotton gauze type air filters.

Another thing to note is that the surface area of "paper" air filters is also somewhat variable. I noticed that my OEM "paper" air filter has about 1.5X the surface area of a popular aftermarket replacement "paper" air filter.

"Paper" elements, with their greater amount of pleats, generally have much greater surface area than the cotton gauze type. I would contend that this is why the pressure drops for both types of air filters is surprizingly simmilar.

[ July 27, 2003, 11:06 PM: Message edited by: Rick in PA ]
 
I don't know what this proves?

All I see is discolored paper. No microscope analysis of weather it is dirt and what size the dirt particles are?

Looks are deceiving and not always what they appear to be.

Automotive air filters are not intended to clean the air, they are designed to filter out dirt in the 5 and up (some claim) micron size.

Also it seems that some of the filters were cleaned and re-oiled. Wonder why that was done? is it possible that they did not give the same results if they were tested new out of the box?

I noticed h is not inclined to take the manf. word on anything so it would appear to this observer that he is biased from the get go.

Why is this even out there? This is on his final page..
quote:

Like everything in life, this filter test wasn't done right the first time. Nothing ever is.

edited for typos, forgot to run spell checker..

[ July 28, 2003, 07:20 AM: Message edited by: Mike ]
 
Well I'll make a few comments.

1) I'll submit to you that surface area of the filtration material is not nearly as important as the total volume of the filtration media. Certain filters like the Mazda OEM would measure poorly in surface area, but have a significant volume compared to the others.

2) No test is perfect, and there are plans for future testing that will address some areas that will be easy to improve. These areas are already mentioned on the page. If you take them out of context and chop only one sentence out stating the test isn't perfect, then you are really reaching to say it is invalid. Believe what you like, but only real data proving the contrary will ever sway my findings.

3) There was a repeatability test performed on one of the filters to determine the relavancy of the filtration test. The results were the same for the repeat test. The repeat test was done on the Baldwin filter. This is mentioned in the test.

4) The deposits left by the K&N and Amsoil filters are not oil residue. I put a few drops of K&N oil on a test filter. It stays nice and red, and doesn't blacken even after sitting for 6 months on my shelf. The deposits on the non oiled filters are identical to the ones on the oil filters, only there is less deposit density on some compared to the others.

And yes, I am not inclined to take manufacturers words on anything, especially when it comes to the automotive aftermarket. Do you really believe Castrol's oil is synthetic? They say it is. That is just one example. Manufacturers are far to concerned with the bottom line profitability and care very little for the customer.

The list of aftermarket automotive suppliers that are no longer allowed to advertise due to FTC sanctions grows every year. Slick50 and Splitfire plugs come to mind. They claimed all sorts of wonderful stuff. People still purchase engine additives containing teflon too, only under a different name. 3M the manufacturer of Teflon says that it should never be used in an internal combustion engine. Of course, 3M isn't trying to sell me something for my car either.

5) As for the miraculous secondary filter. There is no such thing. Any secondary filter would've trapped particles passing through the first filter. I think next time I'll go with a Mazda OEM as they are white and not the orangish tint of the Fram. If you study systems engineering, statistic or redundancy, you'll find that putting filters in series always increases the overall filtration ability. If you have two filters that are 95% efficient and put them in series, you end up with a filter that is 99.75% efficient.
 
Anthony, thanks for sharing your tests with us. I strongly suspect that the relative efficiencies of filter types you found will hold true.

And for the critics, a quote from Teddy Roosevelt:

Far better it is to dare mighty things, to win glorious triumphs, even though checkered by failure, than to take rank with those poor spirits who neither enjoy nor suffer too much, because they live in the gray twilight that knows not victory nor defeat.

patriot.gif
 
Anthony - thank you for taking the time to respond. I respect you for that and running the tests.

What I mean about the oil isn't so much that the darkness is from the oil, but rather the oil coated dirt particles (and some tiny amount of oil) stick to the secondary filter MORE than "dry" particles through the paper filters. I really think a scientific analysis of the deposited material will solve this, not purely visual, (or worse, web photos!)

I also wonder if there is a method to determine how much of the dirt is from around the filter, rather than through it. I have stated publicly here, my biggest complaint with Amsoil planar air filters is a very imperfect edge seal.

Lastly I meant what I wrote about the passed dirt not showing up in my oil analysis', for examples my Volvos and my Toyota all have/had Amsoil oil filters. The older 245Ti gets 10,000 mile oil changes per Amsoil's max recommendation. Si, Na and wear metals (Fe, Pb, etc) are NOT high. The 96 855 went 20,000 miles on the same oil, 15K miles were with an Amsoil air filter - elemental analysis was extremely low.

I really like your testing. You are 1000% ahead of the average garage joe. I actually solute you!
patriot.gif
But - you have doubts about mfr claims, I have doubts about your testing.
wink.gif
 
Anthony,
Based on what I read in your test, it confirmed my positive opinion of the K&N air filters. For one, it confirmed K&N's claims that they flow better. Even if it's only slightly better the difference probably gets bigger at higher power levels / flow rates. And it seems that they do filter "good enough" to protect the engine.
 
Pablo, the Amsoil Miata filter has no rubber seal. The filter I got was actually oversized by about 1/2" all around. I just squeezed it down into the airbox. I seriously doubt any dirt could have gone around it as the airbox is rectangular and the filter assumed its shape very well. All other filters had rubber seals. For the pressure loss testing without a filter, I actually used one of the seals to seal the airbox.
 
I had used the Amsoil foam on three engines years ago. UOA on all and when the Amsoil filters either stretched out or fell apart from heat I went back to the OEM paper. The UOA for silicon content decreased! OEM air filters are king IMO!
 
quote:

Originally posted by mph:
My silicon ppm improved substantially since ditching the K&N and installing a paper filter. I don't know for sure what's "good enough" and what isn't, but I'm not going back to the K&N.

Ah I should clarify. The application is a custom built race car that sees frequent autox and periodic street use. Max HP rules, all I want to do is keep big particles out of the engine. The car comes from the factory with a custom intake and K&N air filter. The K&N seems perfect for this application.

I use OEM air filters in my other cars.
 
A friend just received emails from both K&N and Amsoil regarding the airflow specs of their filters for a 2001 5.9L Dakota QC. Here's what they sent:

K&N = 478 cfm @ 1.5" of water pressure
Amsoil = 200 cfm @ 0.25" water pressure (approx 320 cfm @ 1.5" water pressure)

Based on the manufacturers flow data, it appears that at the same pressure the K&N flows much more air than the Amsoil foam filter. Is there anything I'm missing in that comparison?
 
dd91 -
smile.gif
good one!

r2r - I'm willing to concede some shapes of K&N flow better than some Amsoil filters, but for the most part they are fairly close - heck look at the debatable air filter test that Bob posted - I don't understand how you arrived at:

200 cfm @ 0.25" water pressure = (approx 320 cfm @ 1.5" water pressure)? are both these figures from from Amsoil or is the part in parenthesis calculated?
 
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