k&n vs foam [Archive] - ATV Riders Forum

Ry007

08-08-2007, 07:26 PM

I have had the best of luck with my K&N.....I ride all extreme conditions and have found that with the outerwear it is pretty much invincible. I even ride with no airbox lid. Keep her clean and you'll be fine. I did notice the air flow difference is dramatic over the UNI or stock...

buster024

08-08-2007, 08:20 PM

K&N is one of the most respected air filters on the market. Saying "they suck" or "they blew up my bike" is fairly ridiculous. Foam filters/Uni-filters are also well thought of. I have used K&N filters in all of my trucks, cars, motorcycles, and quads my entire life, and have never blown anything up. Careless riding in water or extremly harsh or dirty conditions may be too much for any filter to withstand entirely. Filter maintenance is paramount to your quads health, no matter what brand you get. Keep your K&N or Uni clean, and you will be happy with either.

project400ex19

08-08-2007, 08:21 PM

Here's the thing. K&N Filters flow MORE when they are dirty. If you took a dirty foam and dirty k&n the foam would lose. But I do not trust K&N. My brother is an automobile mechanic and every engine builder says to stay away from K&N and so we follow suit with our quads also. Just keep a foam one clean and it will flow a lot better. The *paper* style filter has a greater chance of allowing small particles through. Hope this helps in your decision making. I would get a Uni or just Keep your stocker always clean. Just take out the metal piece inside of the stock filter that will increase air flow.

firefighterjosh

08-08-2007, 08:24 PM

Just get the foam and save your self the headache

honda300EXtreme

08-08-2007, 08:28 PM

people say stay away from k&n due to neglectfull owners,, people always tend to overoil, or not clean properly,

and a k&n with a prefilter will filter just as well as a foam....

firefighterjosh

08-08-2007, 08:41 PM

Originally posted by honda300EXtreme
people say stay away from k&n due to neglectfull owners,, people always tend to overoil, or not clean properly,

and a k&n with a prefilter will filter just as well as a foam....

I never had a problem with my K and N. I always used a out wear as well. When i didnt use a outer wear I would always have dust sitting inside my carbs.

I tested it.

If you ride in dust get FOAM!

GPracer2500

08-08-2007, 08:48 PM

I ran a K&N on an EX for many years. During that time my engine did not blow up nor did I ever feel like it did an inadequate job of filtering.

HOWEVER, once I opened the engine for some upgrades I saw some things I didn't like. My intake valves were pretty heavily worn and the bore could have looked better. Tiny particles of dust in the intake air are known to be major contributors to this kind of wear. How much of that wear would have been there no matter what filter I ran? It's impossible to say. I felt the wear was more excessive than it could have been. I now choose to run a foam filter instead (in most cases).

If you often ride in dry, dusty conditions I would not run a K&N. In other conditions, the difference in filtration may not matter enough to worry about.

just $0.02

gcart2

08-09-2007, 10:08 AM

Originally posted by buster024
K&N is one of the most respected air filters on the market. Saying "they suck" or "they blew up my bike" is fairly ridiculous. Foam filters/Uni-filters are also well thought of. I have used K&N filters in all of my trucks, cars, motorcycles, and quads my entire life, and have never blown anything up. Careless riding in water or extremly harsh or dirty conditions may be too much for any filter to withstand entirely. Filter maintenance is paramount to your quads health, no matter what brand you get. Keep your K&N or Uni clean, and you will be happy with either.

lol i always kept oil with me and a spare filter. i would take ofvf my filter after riding in soem dust for a while and notice sand/dirt all the way down. dont tell me they are the best.

XXXRACER165

08-09-2007, 10:35 AM

I properly took care of my K&N, whenever I pulled it off for service there was a coat of dirt in the intake boot. I switched to WB's powerfilter

EX LONERIDER

08-09-2007, 10:40 AM

personally, i had the K&N since my bike was new. 5 years later when i tore into the motor i also seen some things that raised a red flag. first was the intake boot. i ride at the dunes and at ocotillo. so theres much fine dust and sand in the air that has to be filtered.

when i put the K&N in initially, i coated the intake with some sticky foam oil. in the 5 years its been in. i had collected **some** fine particles of sand. i smeered my finger along the intake and seen that sand/dirt had made it through the K&N. other then there, thats the only place i seen traces of dirt getting past the filter. luckily enough, most of the stuff had stuck to the oil in the boot and didnt make it past any further to cause further wear on the motor.

now, with this in mind i took the best of both worlds and used the K&N filter with a uni filter outter. actually, i used a uni 14" oval outterwear and double wrapped it around the K&N. granted its stuffed in there pretty snug but i doubt its going to allow much to get past in concerns to dirt.

like mentioned, i believe K&N's get a bad rap due to neglected matinance. if you clean them and oil them accordingly, they work just fine. a uni will work just as good and is relatively just a notch better then K&N and usually cheaper too.

zdowell

08-09-2007, 10:42 AM

Anyone want to buy a K&N filter? I have one I don't use. Its in great shape.

davetheslave

08-09-2007, 10:47 AM

how many people have taken that metal screen filter out of their foam filter? I was wondering if that really made a big difference, and if it is even a safe idea.

NacsMXer

08-09-2007, 11:47 AM

Foam filters much better in my opinion. Much thicker/more porous media for junk to get trapped in.

I've seen K&N's pass very fine dust into my intake tract first hand; the mess it creates can't do much good for the longevity of a motor. My UNI foam filter keeps that same intake squeaky clean.

While I have no problems running a K&N on the street in my truck, I feel it is much smarter to run a foam style filter in my quad when things get really dusty :o

NacsMXer

08-09-2007, 11:50 AM

Originally posted by davetheslave
how many people have taken that metal screen filter out of their foam filter? I was wondering if that really made a big difference, and if it is even a safe idea.

That metal screen keeps the filter from collapsing on itself when you're on the gas. Wouldn't really be worth much to take it out.

Kaleigh

08-09-2007, 12:21 PM

K&N are great filters but for quads I would go with a foam.. they're easier to clean and oil and they keep out more dust..

Foam is the way to go..

buster024

08-09-2007, 01:39 PM

lol i always kept oil with me and a spare filter. i would take ofvf my filter after riding in soem dust for a while and notice sand/dirt all the way down. dont tell me they are the best.

If you actually read the post, I never said they were the best. I said if you take care of them, they will take care of you. I also stated that foam filters are highly respected as well. Your point of "K&N blew up my bike" is irresponsible. You blew up your bike by riding in conditions not suited for your bike, and it's modifications.

08-09-2007, 01:53 PM

as long as you have the outerwears prefilter you should be good. And if you run opoen airboxlid I suggest getting the outerwears airbox cover. If you have tat you shouldnt have problems. Also I have seen someone cut the 1st stage of the stock foam filter out and slip it over the K&N when they ride in dusty areas. It was in one of the other threads i'll try to find it

fastredrider44

08-09-2007, 03:20 PM

I would personally go with a foam filter. On that same note, if they're not taken care of, they wil cause a new kind of headache. I knew a guy, (no one ever accused him of being smart) that never oiled his foam filter. It ended up dry rotting on his fourwheeler, and made a mess. However, I still have to say that if you care about your fourwheeler, and take care of it, foam is the way to go.

450rJam

08-09-2007, 04:58 PM

K & N all the way

you bump the compression, add a cam,put on exhaust, cdi to rev past its intended limit etc. etc. etc.
all these take away from longevity/reliability
its a chance you are willing to take for performance.
like choosing the best flowing filter available.

I maintain my atv's well and have always ran the k&n with pre-filter, never had a problem (maint. and a good seal to intake are important)

400exrapes

08-10-2007, 01:03 AM

lmao im suprised one rascal on here didnt say Did you know theres many threads on this already?

08-10-2007, 11:10 AM

I mentioned about other threads and solutions they had in my post

coryatver

08-10-2007, 04:54 PM

I love how people say "Oh as long as you have the outerwears prefilter you should be good"

OK WHY DO I NEED A FILTER FOR MY FILTER?? That is ridiculous.

lets see 50 bucks for a K&N plus 20 bucks for an outerwear or like 25 for a foam filter that works just as good

and those who are like oh i will sacrifice reliability for performace well guess what flow benches time and time again have proven K&N's with outerwears don't flow any more than a good UNI or twin air foam filter. And if you run a straight K&N for performance and don't care about the reliability might as well take the filter off all together

project400ex19

08-10-2007, 06:02 PM

Originally posted by coryatver
I love how people say "Oh as long as you have the outerwears prefilter you should be good"

OK WHY DO I NEED A FILTER FOR MY FILTER?? That is ridiculous.

lets see 50 bucks for a K&N plus 20 bucks for an outerwear or like 25 for a foam filter that works just as good

and those who are like oh i will sacrifice reliability for performace well guess what flow benches time and time again have proven K&N's with outerwears don't flow any more than a good UNI or twin air foam filter. And if you run a straight K&N for performance and don't care about the reliability might as well take the filter off all together

Exactly...Very well put.

450rJam

08-10-2007, 06:22 PM

run the outerwear in dusty conditions and the bare k&n if not

uni filters are good or there wouldnt be as many out there as there are

K&N has had the market cornered for a long time, by producing more flow than anyone else

krt400ex

08-10-2007, 08:16 PM

Originally posted by gcart2
I BLEW MINE UP CUZ OF K &N. THEY SUCK FOAM IS GREAT =)

my valve seals started to go bad last yr because of the k and n i was running...and it has only gotten worse. i was getting dirt in my intake, and i was cleaning and oiling the filter properly and with every 3-5 hrs of riding. i switched to foam (twin air) and havent had to clean my filter yet, and i got about 20 hrs on it since i switched the filter

zdowell

08-10-2007, 09:33 PM

Cory that is perfect way of putting it. I know have the perfect response to anyone that says k&n v. foam.thanks. I would like to add that people take short cuts in areas they shouldn't. People who are like, "I need a performance boost, lets get a k&n" where they should be putting a cam in or something else. You shouldn't scrap for horse power by sacrificing longevity.

gcart2

08-11-2007, 04:38 AM

450rJam

08-11-2007, 06:54 AM

most of the things we do sacrifices reliability for performance

each person has to choose where they want to be in the ratio
performance/longevity

project400ex19

08-11-2007, 07:01 AM

Originally posted by 450rJam
most of the things we do sacrifices reliability for performance

each person has to choose where they want to be in the ratio
performance/longevity

But a clean filter is a clean filter. And the only time a K&N shines is when it is dirty. So don't be lazy about cleaning your filter and get a foam filter. Then you will not have to worry about is my crappy K&N letting in particles? A foam filter will flow just as much air as a K&N and you don't have to sacrifice reliability with a foam. So why buy a K&N. So you can put a K&N sticker on everything you own. Wow that's cool.

450rJam

08-11-2007, 07:14 AM

how does it flow better dirty ? I dont have a flow bench but I asumed like any other type of filter that dirty equals less flow

I clean mine all the time to keep it from getting clogged up with dirt/dust

is the stock foam inferior to the foam uni/white in flow?
what about protection?

im off to do some more research

project400ex19

08-11-2007, 07:21 AM

Originally posted by 450rJam
how does it flow better dirty ? I dont have a flow bench but I asumed like any other type of filter that dirty equals less flow

I clean mine all the time to keep it from getting clogged up with dirt/dust

is the stock foam inferior to the foam uni/white in flow?
what about protection?

im off to do some more research

It is proven that a K&N will flow more than a foam. When it is dirty. we have dynoed my brother's 400ex and my 400ex. Both CT racing exhaust. Same jetting, we are pushing the same hp numbers. I used to have a K&N with no airbox lid. and he ran a stock filter with a K&N lid. There is exactly no difference. but I did notice a diry air intake tube with my K&N. It wouldn't fit into my Aluminum airbox anyways. So i threw it on the ground bought a UNI and threw my K&N away. My brother is an Auto Mechanic and goes to performance classes and every guy there says stay away from K&N. What I'm saying is you don't have to sacrifice reliabilty or performance if you just keep a foam filter clean. No matter what brand foam filter it is.

JDMThoughts

08-11-2007, 08:11 AM

My feeling is K&N isn't as good as every says. It's better than stock, but not the easiest one to clean, and many people who aren't so mechanically savvy can't seem to get them cleaned correctly. I have a K&N on my Banshee and it works, but I had a Uni on my 400 and switched to a foam style Sparks filter so I would say go with foam as they are simpler to clean in my opinion. K&N filter recharging is like a 2 hour affair. You need to tap the loose dirt off, rinse it then use the cleaner, then let it dry for a while, then apply the oil and then let it dry some more and then finally bolt it back on.

ride-to-live

08-11-2007, 08:16 AM

All i have to say is k&n Rule. I have had them on all my quads if i didnt have a Uni... get a Uni or k&n they both rock.

450rJam

08-11-2007, 01:45 PM

ok, the crap about the k&n flowing better when dirty is false, it actually looses its flow advantage rather quickly if it isnt cleaned
and maintained properly,
JDMthoughts-----do not rinse prior to cleaner,and do not let the cleaner dry on filter.
1. soak filter with cleaner (both inside/outside) let soak 10 min.
2. rinse good with water from inside out & shake off excess
3. re-oil (till the filter is pink, dont over oil)
this is perfect example improper cleaning/maint.

the foam filter does break down from cleaning due to the message of the soap/water to clean and the rub of re-oiling

I read so many articles and graphs of flow vs filtration of K&N (cotton)vs uni/amsoil/white (foam) vs fram and others (paper)

conclusion is that the K&N flows better but not by alot and the
foam filters better but again, not by alot. maintain which ever you choose and it will keep you happy.
google it or ask jeeves or how ever you search, there are alot of tests by unbias people/agencies for your viewing pleasure

project400ex19

08-12-2007, 08:19 AM

[QUOTE]Originally posted by 450rJam
[B]ok, the crap about the k&n flowing better when dirty is false, it actually looses its flow advantage rather quickly if it isnt cleaned
and maintained properly,

Well I know from personal experience that they do. Go talk to some real engine builders. guys from Gale Banks Engineering, Super Chips, none of them even reccomend K&N, they actually advise people to stay away from K&N.

Like u said the K&N barely allows more airflow than a Foam filter. So why not keep your dependability for the same amount of power and own a Foam Filter?

Why would curtis sparks and a bunch of other QUAD Engine builders offer only Foam if they weren't the best?

kilgoja

08-12-2007, 11:40 AM

personally i've never even thought about trying a k and n....why pay more money for less filtering?....more airflow = less filtering...it's just common sense....even the foam filters allow fine dust into the carb....that's just part of the atv world....u just want as little as possible to get in there to keep it clean as possible...so cleaning ur filter on a regular basis is the way to go...i have the stock filter and a moose racing filter that is pretty much the same foam.....i just rotate them out...uni or twin air is good too....i think people worry too much about a "little" more performance...such as more airflow or whatever....it's really not worth it....go buy a 450 or a 700 if u want more performance.....pretty much the more u "modify" an atv away from how it was designed the more reliability u are taking away from it....that's just how it is....i mean if u have the money and reliability isn't what ur after then go for it....but basically most aftermarket stuff that promises "more" is just bad for ur atv in the long run....i try to stick with stock parts or aftermarket parts that are equal to the stock parts...honda knows how to make reliable quads....they don't need help from other companies...lol

08-12-2007, 12:20 PM

that is very true but exhaust and other parts DO NOT harm your engine. The only thing that really takes away your atvs life is being dirty or opening up the engine and changing something. I bought a K&N due o the fact they are so much easier to clean! For me its easier to maintain a K&N than the foam filter. If you use the prefilter(outerwears) that blocks more than the foam filters. After riding the outerwear is covered with dust but when you take it off the filter is almost as good as before you went riding as with the foam all that dirt just gets trapped in. IMO its better to keep the dust out than store it in your filter. To me open airbox lid is what will harm your atv, if you put the powerlid or outerwears airbox cover you are fine but running it completely open is how the dirt gets into everything.