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View Full Version : 80 Series K&N vs. OEM Air Filter


corsair23
05-20-2007, 11:22 PM
Not sure if this is tech or chat...

I was doing some PM on the '97 FZJ80 today. While waiting for the AT fluid to drain out I decided to put in my new OEM Air Filter (thanks CDan) and take out whatever the PO had in there.

BTW, I know most folks say to remove the air cleaner hose so you don't crack it but I've found that by simply loosening the clamp at the throttle body you can rotate the hose and the air cleaner cap enough to easily remove the air filter without putting stress on the hose.

Anyway, when I pulled the filter out I noticed a fair amount of oily grime on both the top and the bottom of the air filter and in the bottom of the can. I recognized the look of the filter as that of a K&N and sure enough, when I wiped away the grime from the top of the air filter it was clearly marked K&N. The other thing I noticed was that the size of the K&N air filter was considerably smaller than the OEM air filter.

I've read various threads on MUD regarding K&N air filters and about not using them due to the oil in the filter getting into the hose, MAF, etc. Based on what I saw I would have to agree 100% with those that warn against using a K&N (ran one for years on my '99 Durango thinking it was the best air filter out there :().

Here are some pictures showing the obvious size difference between the filters and of the grime that I wiped off the air filter and out of the air filter can. The shop wipe with the oil on it is the one I used to wipe off the filter. The other two were used to clean out the air filter can. I used BOTH sides of the shop wipes and the other side looked about the same as what you see grime wise :eek:

P.S. Anyone want a K&N air filter before I toss it? FREE but let me know quick :)

.

Hulk
05-20-2007, 11:32 PM
Jeff, I'll take it. I'd like to clean it out and run some highly subjective street tests with an A/B comparison.

corsair23
05-20-2007, 11:49 PM
Jeff, I'll take it. I'd like to clean it out and run some highly subjective street tests with an A/B comparison.

It's all yours Matt :thumb:. Want me to bring it to the next meeting?

I don't have a K&N air cleaner kit anymore (went with the Durango when I sold it) but I think they're only like $20 or you can always use other items. FWIW I never noticed any improvement on my Durango. But I guess when you are talking only an ~11 HP increase (per K&N) and stock the 5.9L Durango put out 235 HP I'm not sure what I was thinking :hill:. I had both the FIPK Stage I (just the air filter) and then the FIPK Stage II (open cone filter with the shroud and intake hose). Although with the Stage II you could hear the difference (big sucking sound :hill:).

Oh, and the filter itself looks pretty darn clean. The grime was mostly located on the top and bottom of the filter and in the bottom of the can...But then again the filter on my Durango always looked clean as well.

Hulk
05-21-2007, 12:31 AM
Next meeting is great. I have a cleaner kit already. My understanding is that the K&N may make a difference on the street, but it's less effective on a dusty trail. I'd like to mess with it a bit and see what I come up with. Thanks!

Romer
05-21-2007, 05:20 AM
You don't want to run a K&N filter. do a search on Mud and you will see why.

Red_Chili
05-21-2007, 07:22 AM
Ditto. I have run K&Ns on several vehicles including my wife's street-going BMW motorcycle. Some will say they pass dust only if you don't keep up with cleaning, but I have found they do regardless of whether new, freshly cleaned, etc. I have found fine dust in the intake after the filter.

I currently run a K&N on the Chili mostly because there is no longer any such thing as a stock filter for it. However, I run the K&N foam prefilter, oiled with NoToil oil (fantastic stuff, sink and water cleanup, yet waterproof). Seems to do acceptably but there is no substitute for a paper filter in an airbox.

Hants
05-21-2007, 08:21 AM
Back in the 80scool/lcool days, someone (probably from down under) advocated a simple test: But a blob of grease in the intake (after the filter), then drive for a while. Everyone who tried it quickly had dust/dirt on the grease. :eek:

I'm sure that with the larger pores, there's less pressure drop across the K&N (given filters of the same surface area). Based on the pictures above, the OEM has significantly more surface area, though (deeper folds, larger filter diameter).

You won't find a K&N on my rig -- not even for evaluation!

nakman
05-21-2007, 08:34 AM
Good move ditching that thing Corsair... they are not good. did you clean out the tuna can?

And coincidentally I tried washing my paper one yesterday, the water didn't seem to make any of the dirt leave, and I swished it up & down about 50x. I'm just going to get a new one...

Hants
05-21-2007, 08:45 AM
...I tried washing my paper one yesterday, the water didn't seem to make any of the dirt leave, and I swished it up & down about 50x. I'm just going to get a new one...

Did you try compressed air (inside to out)? I've got my "spare" sitting in the garage awaiting a blow-out. I just assumed it would be like other filters, so didn't worry. :confused:

nakman
05-21-2007, 08:49 AM
I didn't want to sit there all day blasting it, I guess I could have done a better job. The dark dusty areas just became dark and mud-like in the water, but then when it dried it was just dark and dusty again.

corsair23
05-21-2007, 10:55 AM
My understanding is that the K&N may make a difference on the street, but it's less effective on a dusty trail. I'd like to mess with it a bit and see what I come up with. Thanks!

Word is the dirtier a K&N gets the better it is supposed to work :confused:. You're really only suppose to "clean" them only so often which IIRC isn't near as often as you would replace a regular paper filter.

I would fathom a guess that this is because the filter gets clogged up and subsequently less crap can pass through over time :hill:

corsair23
05-21-2007, 11:02 AM
Good move ditching that thing Corsair... they are not good. did you clean out the tuna can?

I surely did :D

The top right and bottom shop wipes in the above pictures are what came out of the tuna can. Found no such stuff in the LX when I took out the aftermarket paper filter that was in it and put in an OEM filter.

K&N does state to not over oil the filters when you clean them but that is subjective and more often than not people assume more is better...I can only guess the PPO felt that way. I know it wasn't the PO who did this (realtor guy than knew nothing about vehicles) and according to him the guy he bought the 80 from was a Cruiser nut :rolleyes:

On a side note, it was nice seeing bright red ATF coming out during the AT drain so I just did a drain and fill on the 80 as opposed to a full 20 qt swap like I did on the LX :eek:

nuclearlemon
05-21-2007, 11:25 AM
there's oil in the cleaner because whomever serviced it over oiled it. a common issue. you're only supposed to get it damp, not soak it with oil. many people spray it until the entire thing is pink because that's what they look like when they come from the factory. after you clean them, put enough oil to get a light pink shade, but it will be much whiter than a new k & n filter.

i run k&n's in everything because of their life. i don't make a lot of money and have way too many vehicles to be spending $25/vehicle every six months or so.

the minute amounts of dirt that might get passed them will find a way into the engine anyways. of course, i don't run one of them new fangled sensitive motors...everything i've got is junkyard/tractor stuff that isn't easily effected by the smallest amount of dust.

i also don't run synthetics, i run fram oil filters, valvoline oil, plain jane marine grease in my hubs, and whatever 90wt shoco has in stock. while i agree that there are some things where you shouldn't buy the cheapest stuff out there, i think too many people take a lot of it way too seriously.

Beater
05-21-2007, 11:50 AM
i run k&n's in everything because of their life. i don't make a lot of money and have way too many vehicles to be spending $25/vehicle every six months or so.

the minute amounts of dirt that might get passed them will find a way into the engine anyways. of course, i don't run one of them new fangled sensitive motors...everything i've got is junkyard/tractor stuff that isn't easily effected by the smallest amount of dust.

i also don't run synthetics, i run fram oil filters, valvoline oil, plain jane marine grease in my hubs, and whatever 90wt shoco has in stock. while i agree that there are some things where you shouldn't buy the cheapest stuff out there, i think too many people take a lot of it way too seriously.

Hear Hear.. Couldn't have said it better

Hants
05-21-2007, 12:03 PM
i also don't run synthetics, i run fram oil filters, valvoline oil, plain jane marine grease in my hubs, and whatever 90wt shoco has in stock. while i agree that there are some things where you shouldn't buy the cheapest stuff out there, i think too many people take a lot of it way too seriously.


HERESY!!! :hill:

If you were on MUD, you wouldn't merely be flamed, you'd be nuked, for such utterances! :rip:


:lmao::lmao::lmao::beer:

wesintl
05-21-2007, 12:05 PM
Yeah. but you nickel and dimers need to take into acct water to spray out the filter, cleaner and new oil and beer consumed while waiting for the cleaner to set in and the filter to dry. It really isn't that *MUCH* cheaper. I have one in my camry but I prefer paper. Once i'm out of oil and cleaner i'm going back to paper. I don't like K&N.

SteveH
05-21-2007, 12:33 PM
My father once said 'The brand of oil isn't nearly as important as keeping some in there' - and I have met folks that go on and on about using only Valvoline or some such and then also admit that they let it run low on occasion.

I wrote K+N years ago, asking about filter efficiency, and they sent me a photocopy of a test conducted on a K+N filter by a company in England. The test was paid for by K+N, and was an efficiency test on the '95% largest particles that were typically trapped by the filter'. The test results were badly written, and of course mentioned nothing about 'the other 5%'. I thought if this report was the best K+N could do, I would part my relationship with them. They sent a paper copy, and I don't have it anymore.

It would be nice to see Four Wheeler or Car Craft do an objective test on a K+N filter instead of another error-ridden 'what hits and what fits' tire guide.

Steve

Red_Chili
05-21-2007, 12:37 PM
I just wish I could find a full-blown foam filter for my truck, a la what I run in the Nuclear Thunderpig (Honda XR650R). It gets EVERYthing, becomes nasty nasty dirty (the images after riding the Kokopelli Trail are fresh in my mind), yet behind it the airbox is spotless. And it cleans up with NoToil detergent in the kitchen sink. And fresh NoToil oil as soon as it dries, squeeze it, plop it into position, good as new.

I want a foam truck filter!

(I am close with the K&N prefilter, but it is not as fine a filter as the version on the bike, and it uses a regular K&N as a sort of filter holder...:p: )

corsair23
05-21-2007, 01:01 PM
there's oil in the cleaner because whomever serviced it over oiled it. a common issue. you're only supposed to get it damp, not soak it with oil. many people spray it until the entire thing is pink because that's what they look like when they come from the factory. after you clean them, put enough oil to get a light pink shade, but it will be much whiter than a new k & n filter.

Agreed and based on what the one I have looks like, Matt may never have to oil it again :hill:

wesintl
05-21-2007, 01:29 PM
I just wish I could find a full-blown foam filter for my truck, a la what I run in the Nuclear Thunderpig (Honda XR650R). It gets EVERYthing, becomes nasty nasty dirty (the images after riding the Kokopelli Trail are fresh in my mind), yet behind it the airbox is spotless. And it cleans up with NoToil detergent in the kitchen sink. And fresh NoToil oil as soon as it dries, squeeze it, plop it into position, good as new.

I want a foam truck filter!

(I am close with the K&N prefilter, but it is not as fine a filter as the version on the bike, and it uses a regular K&N as a sort of filter holder...:p: )

I thought the general consensus is that foam filters trap the least amount of particals? Hence the reason you can't get them for autos. :confused:

Inukshuk
05-21-2007, 01:57 PM
I plan to retrofit two VW Oil Bath Air Filters to my 80.

nakman
05-21-2007, 02:34 PM
I plan to retrofit two VW Oil Bath Air Filters to my 80.

Get the supercharger, then convert the stock air cleaner housing into a big water tank, then ram all the air through it.

You'd have the first ever air intake bong... :smokin: :lmao:

Uncle Ben
05-21-2007, 04:54 PM
Get the supercharger, then convert the stock air cleaner housing into a big water tank, then ram all the air through it.

You'd have the first ever air intake bong... :smokin: :lmao:


Rut Ro....this just went off topic....take it to the hookah thread! :lmao: :hill:

On the other hand as long as you don't step on it after the conversion technically your truck didn't inhale which makes it OK.....:rolleyes: