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Discussion in 'The Garage' started by ntsqd, Apr 11, 2005.
Think again: TEST
Might be a repost, but I've not seen it ref'd here b4.
"A paper filter does not do well if directly wetted or muddy. It may collapse. This is why many off-road filters are foam. It is a compromise between filtering efficiency and protection from a collapsed filter. Now how many of our trucks collapse their filters from mud and water?"
2nd paragraph from the bottom.
I know I have gotten my filter wet more times than I can count that is why after the first time I got a K&N. They do serve a purpose to off-road driving in water and mud.
I have an expanded steel grid around my filter just for that reason.... can't collapse with steel in the middle of it.
Wish i knew the poor filtering qualities of the k and n before i spent 100 bucks for the filter and chrome xtreme lid.... that is why i'm going prefilter on it. best of both worlds. If i didn't have so much money into it i would have gone ac delco.
I've been saying it for years but no one listens... K&N sucks!
It seems like there was an exact trade off between filtering and restriction. I guess it depends on your priorities, but I'd run AC after seeing this.
I listened. I just keep a good factory type elememt in everything I drive and call it good.
A race engine that gets rebuilt a bunch is probably not that big of a deal and helps to use a K&N on.
I think I read somewhere recently that even in the diesel trucks the K&N stlye filters are only marginally high flow than a new stock filter.
Maybe theres something I'm missing here, but can't you keep water and mud off an air filter with a snorkel or something?
If my air filter got wet enough to collapse, by the time that happened, the engine would be hydrolocked, and thats with the stock air cleaner housings.
I'm assuming perhaps that has to do with personal preference to "open" vs "closed" air cleaners?
is there a test with the prefilter on it? I want to know if i should just scrap my whole k and n setup...
does the foam or other material prefilter work better?
its a repost and always sparks a big debate post.
/me sits back and waits for the fallout.... while changing his OE style filter for the same damn thing....
except now i'll admit k and n's filter like a screen door.
Ahh, here we go.
Everyone thinking of posting in this thread, read this, see your question posed, answered, argued about endlessly, beaten like a dead horse, and then rejoice.
Being in So. CA I tend to forget that issue. I would rather duct the intake to someplace well baffled from water than use a K&N.
Whether the filter collapses or not, a wet paper filter still doesn't work very well. Ask any oil burner driver with a RACOR that didn't get drained soon enough. They'll tell you how poorly a paper filter passes anything when saturated with water.
And just to show you what a hypocrit/lazy SOB I am, my 'glas buggy has a K&N on it. I hate it, but haven't invested the time to change it to something better.
I would liken an oil-wetted foam type pre-filter to the results of the UNI filter. They are very similar in design.
EDIT: This probably is like a "Which Diesel Engine is better" thread, but I can't help myself. I doubt I can convert anyone to the "One, True Faith" (<-Note: sarcasm), but maybe this will make some think b4 spending $$$.
Bottom line, i'm a little curious who actually performed the test, because as we all know, you can't believe everything you read. Take it with a grain of salt guys. Not saying they are wrong, just that everybody has an agenda.
I believe that the only reason why K&N is so large currently is because they pushed their name into every corner of automotive racing they could so people would always think "K&N" when it came to a "performance" filter. Their filtering is another story...
I run a 5" drop base stock air cleaner. It provides more air than I'll ever need. Since it has a drop base the water sits in the base of the air cleaner. A wet filter doesn't flow for beans. I know this because I've had a wet filter many times.
K&N filters have their uses... mainly when you're limited to a certain filter size and you need the flow. I used to run one on TT races and in the dunes with an Outerwears pre-filter on them years ago. Also did the same on the sandrail with DeLorto carbs on it. Can't run a K&N without an Outerwears prefilter.
Crosscountry racing I used to run a Uni two stage filter and an Outerwears prefilter... lot more dust.
I don't see a reason to run a K&N on most vehicles. They do let more dirt in than a PJ1 soaked Uni or a regular paper element but they also take longer to clog and maintain the same amount of air flow for longer.
What about using a prefilter on a OEM set up to try and resist water? I have always been skeptical about the K&N's and the first time I saw this test was proof enough for me. I just use the tallest FRAM 14" filter I can find.
exactly, I feel the same way about Fram oil filters, they're crap, but when a customer hears Wix and then Fram they always go with Fram cause it's cheaper, they've heard of it, and it's the "orange filter", pisses me off... instead of putting money in the quality of their products it's all put into advertisments.
but on topic, i run a K&N on my truck but after all this i'll be sure to order me a prefilter as soon as i get to work tomorrow.
All I can say is spin spin spin. You give me 20 filters and tell me which one you want to win and I will find a test that will do it. I have seen many of these tests and the only consitancy I have found in them is that the results are not only varied but they are wildly varied. Dyno tests prove a paper filter is a restriction PERIOD end of story as to how well they filter I don't think there are many desert racing trucks running paper filters. In the Paris Dakar rally Purolator sponsered a truck several years ago but after the first day(in Africa) they pulled the air filter and put a K & N on it because the purolator (paper) filter had plugged 3 times I am not saying the K & N is the best but a paper filter in will plug faster than an oiled gauze or foam filter. My own experiance has shown that the oiled gauze filters work well enough for me. Someday I will have enough money to do my own test and I am sure someone will call my test biased too.
Nearly all of the Buggies raced in the California, Nevada, and Baja deserts and quite a few of the trucks use the UMP filters which are lightweight aluminum housings for heavy equipment Paper Filter elements. There are some trucks that use a K&N type filter. Typically they have them directly on top of the engine in a ducted enclosure of some sort. I believe that the only reason a K&N type filter is used in these trucks is b/c the UMP type filters are a big package. Finding a place for it and the large plumbing required may not be possible.
The key is proper baffling and ducting. Look at heavy or off highway equipment air filters for clues. They solved the problem years ago and they do not use a K&N type filter element.
As to the "grain of salt" comments, the article I linked claims to have used commercial testing equipment made for performing such a test and that the test was conducted in accordence with ISO Std 5011. I googled "ISO Standard 5011" and found this: http://www.standardsglossary.com/iso5.htm which confirms that the std. is an air filter test std. Assuming that their claim of the test being in compliance with the std is valid that means that anyone else, in any location in the world can reproduce those results IF they have access to suitable testing equipment.
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