Outer Limits 4x4 Board

Gday chaps,

Do you prefer to use OEM paper filters or oiled filters such as K&N?
What is your reasoning behind your choice?
Pros & Cons of either type would be appreciated also.


I have a dilemma that needs to be sorted ASAP! and your repsonses
will help my cause... I know in my mind which one i prefer and the reasoning
behind it... I would just like to see others opinions and experience before
the shit hits the fan...

I used to run a Finer Filter on my turbo Rocky, but now only use paper elements. The reason, a turbo rebuild needed because of the excess filter fluid that was drawn into the turbo. My own fault, as I didnt get rid of enough fluid when cleaning and reoiling the filter, but how do you accurately judge too little or too much fluid?

i tryed a finer filter on my non turbo 4.2 diesel patrol it was too restrictive on air flow, so now i have a k&n filter. Which lets a lot more air in than factory filter and a lot more than the finer filter.
The good thing about it is you can get the k&n spray oil which is red and it is hard to put to much on the filter. It is what i prefer because the filter from nissan are not cheap and the k&N improves performanc while still filtering as well as oem if not better.

Thanks guys, please others keep it coming...

Doesnt anyone else use an air filter?

got a k&n in my grand vitarta 2.5L v6 and it noticebly increased the power thru the mid range and top end

What are peoples experience and/or opinions on the different types (paper/oiled) in regards to keeping particles out of the engine. The K&N appear to flow a lot more freely and thus provide an increase in performance, but is it at a cost??? what do people think?

Paper off road - better filtering than other types. Just do a bit of a search on the internet and you'll see what I mean.

On road - K&N pod.

K&N all the way, simply because you service it whenever you want. Just tap it on a bench every 5000 or so kays (epending how much dust you go through), and wash every 15,000 - 20,000 kays.

Plus they are more robust than the paper type elements that you can buy.

Really hard to "over oil", easiest thing to go buy is use JUST enough fluid to make the filter from white to pink, resist the temptation to put more....

Donaldson and Mann Filter make the best air filters in the world. They are the two biggest filter manufacturers, and have the best R&D. Most other firms make lower-tech copies of their products.

If you drive in dusty conditions, only fit a K&N if you want your engine to die prematurely due to dust related wear.

If you don't believe me - read this:
http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

Finer filters should, in theory, be LESS efficient than an equivalent (good quality) paper filter, since they use foam, which is generally not as good as a fibrous filter - but I have never tested one, so can not say 100%. But I would place money on them being less efficient than an equivalent donaldson or Mann filter.

ISUZUROVER wrote:If you drive in dusty conditions, only fit a K&N if you want your engine to die prematurely due to dust related wear.

My engine killed itself , its not like i drove across the outback in the zook.

On a more serious note, I found the K&N's to be good and even gave the zook an extra 1/8th power increase to the almighty 1L big block

like the guy from dts turbo said '' ever tried to breath threw a sponge ?''

paper all the way baby

I highly recommend the K&N for on road and beach work however a keep a Toyota one in the truck and fit it when i play in dust. In my mind if 2 minutes work save me a rebuild it is worth it.
Also either will be better off with a snorkel attached; i don't mean a safari or similar (restricting crap) i mean a custom full flow stainless one. I will also be fitting a Donaldson cyclonic precleaner to mine once the snorkel is on, probably buy a normal head too and use it on road.
My 2 cents

My 2 cents worth. Foam all the way. I haven't seen a motorcross bike made in the last thirty years with a paper element filter on it! And they spend their lives in the dirt. Also on lomg trips uou can pull them out a reclean them.

plowy wrote:like the guy from dts turbo said '' ever tried to breath threw a sponge ?''

paper all the way baby

Hay Plowy, wrap your head in cellulose paper and try it Please post your findings or obituary

mick355 wrote:My 2 cents worth. Foam all the way. I haven't seen a motorcross bike made in the last thirty years with a paper element filter on it! And they spend their lives in the dirt. Also on lomg trips uou can pull them out a reclean them.

That is the perfect ammunition to settle this dilemma... Thankyou very much!

Still appreciate others opinions... I concur with several of the above ideas and have my own opinion... Just need more ammunition

Where there is a chance the filter may get wet a foam filter is best, but for keeping dust out paper is hard to beat.

Jon.

I have run genuine air filter since getting turbo installed in 98
until then I was running a finer filter.
Last pair I bought from nissan they were only approx $ 25.00
I change it with the oil at 5000k intervals ( give or take a few K's )

I have run genuine air filter since getting turbo installed in 98
until then I was running a finer filter.
Last pair I bought from nissan they were only approx $ 25.00 EACH !
I change it with the oil at 5000k intervals ( give or take a few K's )

ooops ! typo

South wrote:

mick355 wrote:My 2 cents worth. Foam all the way. I haven't seen a motorcross bike made in the last thirty years with a paper element filter on it! And they spend their lives in the dirt. Also on lomg trips uou can pull them out a reclean them.

That is the perfect ammunition to settle this dilemma... Thankyou very much!

Still appreciate others opinions... I concur with several of the above ideas and have my own opinion... Just need more ammunition

No - that information is completely misleading.

How long does a motorcross bike last between rebuilds - 1000 hours?
How long does a diesel earthmover last between rebuilds - 1000000hours or more?

Motorcross 2-stroke engines don't last anywhere near long enough for the filter to make a difference - all it needs to do is keep the rocks out - with minimum restriction to maximise efficiency.

Did you look at this? The worst THREE filters are OILED foam. (edit)

LuxyBoy wrote:I highly recommend the K&N for on road and beach work however a keep a Toyota one in the truck and fit it when i play in dust. In my mind if 2 minutes work save me a rebuild it is worth it.

On the beach there are lots of small salt particles in the air. Although they are too small to cause engine wear, they will end up in the oil. A high-efficiency paper filter will stop them getting into the engine.

ISUZUROVER wrote:

South wrote:

mick355 wrote:My 2 cents worth. Foam all the way. I haven't seen a motorcross bike made in the last thirty years with a paper element filter on it! And they spend their lives in the dirt. Also on lomg trips uou can pull them out a reclean them.

That is the perfect ammunition to settle this dilemma... Thankyou very much!

Still appreciate others opinions... I concur with several of the above ideas and have my own opinion... Just need more ammunition

No - that information is completely misleading.

How long does a motorcross bike last between rebuilds - 1000 hours?
How long does a diesel earthmover last between rebuilds - 1000000hours or more?

Motorcross 2-stroke engines don't last anywhere near long enough for the filter to make a difference - all it needs to do is keep the rocks out - with minimum restriction to maximise efficiency.

Did you look at this? The worst two filters are foam.

You should also post the performace drop off graph

Heres another angle... the K&N filter is a tight fit, once its in there is no vertical or horizontal movement. The aftermarket paper filter does not seal properly and has both vertical and horizontal movement.

The OEM filter has a better seal than the aftermarket paper but the K&N wins hands down. Isuzurover, I have read that report and of the filters tested the only one suitable for the vehicle in question is the K&N, thus rendering that test useless in the dilemma.

Noting that smaller particles may be allowed to penetrate the oiled filter, I see far more damage can occur from a non-sealing fit than that of, in your opinion, an inferior filter (namely K&N).

Nice graphs with pretty colours and all but it doesn't state weather or not the foam elements are oiled or not! I wish my two stroke engine would last 1000hrs more like 10hrs before they require a new ring, this is because of how hard they are revving. Have you ever heard of a two stroke being dusted? This is when the air cleaner falls off. Engine lasts about an hour before its shagged. After every ride i clean and reoil my "twin air" element. There is never a speck of dust in the intake system.

South wrote:Heres another angle... the K&N filter is a tight fit, once its in there is no vertical or horizontal movement. The aftermarket paper filter does not seal properly and has both vertical and horizontal movement.

The OEM filter has a better seal than the aftermarket paper but the K&N wins hands down. Isuzurover, I have read that report and of the filters tested the only one suitable for the vehicle in question is the K&N, thus rendering that test useless in the dilemma.

Noting that smaller particles may be allowed to penetrate the oiled filter, I see far more damage can occur from a non-sealing fit than that of, in your opinion, an inferior filter (namely K&N).

Of course if a filter doesn't seal properly it won't work. But how does that become relevant to the original discussion. If you have a crap quality aftermarket paper filter that doesnt seal well, buy a better one (e.g. Donaldson or Mann Filter).

mick355 wrote:Nice graphs with pretty colours and all but it doesn't state weather or not the foam elements are oiled or not! I wish my two stroke engine would last 1000hrs more like 10hrs before they require a new ring, this is because of how hard they are revving. Have you ever heard of a two stroke being dusted? This is when the air cleaner falls off. Engine lasts about an hour before its shagged. After every ride i clean and reoil my "twin air" element. There is never a speck of dust in the intake system.

Thats all well and good, but have you ever tested a filter for efficiency???

At work we tested some oiled foam filters for an firm that manufactures F1 filters. After they got the test results back they switched to making fibrous filters, even though F1 engines dont see much dust, and the engine only has to last one or two races.

mick355 wrote:Nice graphs with pretty colours and all but it doesn't state weather or not the foam elements are oiled or not!

If you read the text you will find that it does - the Amsoil, uni and K&N were oiled.

The other filters, most notably the oiled reusable types, had an exponential loading response before reaching maximum restriction. These filters had a lower initial restriction, but they became exponentially more restrictive under a constant flow of dirt. Also notice the length of the curves as it shows the relative test time for each filter (time to max restriction).

BTW - these filters were tested to the ISO air filter test standard. The foam filter were the worst in the test in terms of filtration efficiency and longevity between cleaning/replacement. And although they initally had a low pressure drop, they blocked up faster than the others.

ISUZUROVER wrote:Of course if a filter doesn't seal properly it won't work. But how does that become relevant to the original discussion. If you have a crap quality aftermarket paper filter that doesnt seal well, buy a better one (e.g. Donaldson or Mann Filter).

Thats the whole dilemma, poor quality original and aftermarket paper filters vs the quality of the K&N... I was prompting for persons opinions and experiences in regards to filters in general... why they chose the particular one they are running et cetra.

Now all I need to do is convey not only verbally, but with physical evidence to the other person... maybe then this issue will be sorted.

I am still interested in others opinions, and I am very appreciative of the discussion thus far.

I put on a Hyclone and got 20kw at the blinker stem
I then fitted a Fitch, and gained another 40kw at the air conditioner.
I then fitted extractors, and gained 300kw at the front parker light
I then fitted twin 3inch stacks and gained a hard pee pee
I then fitted foam air filter and gained another 200kw...
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Have tried foam, went back to paper.

"If you read the text you will find that it does - the Amsoil, uni and K&N were oiled."(QUOTE)

ISUZUROVER- I read the info in your text and although it refers to these filters as being the oiled reusuable type I cannot find where in the text does it mention what brand or of how much oil they used on the filters during the testing. This leads my to believe the were tested dry but, I wasn't there so i guess we'll never know. And as i said before, If foam is o bad why have the Japanese being doing it for decades? It can't be to raise money because the top "works" teams are still using foam filters. These companies have the money to spend on R&D so ill stick with them