K&N air filters

So what you're saying is....... K&N filter is far better no matter what environment you're driving in?

Can a k&n be blown out with an air compressor??

If the can be, surely a quick clean up with the air gun at a stop on a dusty trip is a winner.

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Originally Posted by Clunk

So what you're saying is....... K&N filter is far better no matter what environment you're driving in?

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Pretty much. As Winnie said his filter looked disgusting after a dargo trip and his original thought was to use a paper element cos visually the stay cleaner but guess where that dust goes?

Use the filter in the zd30/td42t GU's as an example. Nissan genuine ones are ok as they Are a oil impregnated medium. A paper element once air speeds are increased there filtering potential is greatly diminished to the point where they basically only filter rocks lol. A k&n will still filter as well at air speeds of 12m/sec as it does at air speeds of 4m/sec.

You can get a paper element to work but you need to reduce air speeds to help it do so. Having an induction system with no or very little restriction is the key with an air box that allows all the surface area of the filter to be used. This is why 4" snorkels and custom air boxes are popular when increasing performance on td42's

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Originally Posted by lhurley

Can a k&n be blown out with an air compressor??

If the can be, surely a quick clean up with the air gun at a stop on a dusty trip is a winner.

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It's not ideal no. Mego's idea is a winner here and the cleaning kits for a k&n are small and easily storable. A quick tap out will help. Remember while they might not flow as well as they start to clog they still filter very well.

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Originally Posted by nissannewby

Pretty much. As Winnie said his filter looked disgusting after a dargo trip and his original thought was to use a paper element cos visually the stay cleaner but guess where that dust goes?

Use the filter in the zd30/td42t GU's as an example. Nissan genuine ones are ok as they Are a oil impregnated medium. A paper element once air speeds are increased there filtering potential is greatly diminished to the point where they basically only filter rocks lol. A k&n will still filter as well at air speeds of 12m/sec as it does at air speeds of 4m/sec.

You can get a paper element to work but you need to reduce air speeds to help it do so. Having an induction system with no or very little restriction is the key with an air box that allows all the surface area of the filter to be used. This is why 4" snorkels and custom air boxes are popular when increasing performance on td42's

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Thanks mate, superb explanation as always

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Originally Posted by nissannewby

Your thinking is wrong. K&N filter better at all stages of life than a paper filter. If anything run a paper filter on the road and k&n in dusty conditions.

Honestly mate k&n all the way. They filter better at higher air speeds than a paper element ever will and will filter better longer in dusty conditions. Obviously as the filter clogs the restriction increases so air speeds increase so this is where the k&n comes into its own.

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Very nice Mat you actually do take note eh... And you are correct our ZD air box and paper elements will pass rocks when the front 1/3 gets full in dusty conditions due to restriction hence air speeds past 4 metre/sec. A K&N in the same air box will filter all dust particles above 7 micron no matter how clogged it is, but will restrict air flow enough to lower power in that condition. The odd thing is due to the oil and the method it collects on the surface the filter can look terrible but it does suggest it is working as intended, just have a think about that, and imagine have you ever seen that much dust on your paper element. You have to wonder how well your paper element is actually working or where has all that dust gone.. I think logic should suggest to you which is better..

I learnt something new today.... Thanks Matty!!

I will say that I was surprised how well the K&N filter cleaned up

Do the K&N filters come with a seperate outer dry pre filter that slips over the main oiled filter ? (like uni filters)





I always thought the idea of the round drum air cleaner box was for the cyclonic effect ?, as the air curculates the dirt is thrown to the outside ?


Using a paper filter you may find dirt/dust in the bottom of the air cleaner box, it was my un-educated impression, an "oiled" filter would "catch" swirling dust particles, rather than letting fall to the bottom like a paper filter will ?


I thought the K&Ns would actually visually clog quicker in dusty conditions because its sticky and won't let go of any dust ?





I run a paper filter and a external foam snorkel pre filter, and had avoided a K&N for the above reasons, but now may be interested in a K&N main filter, after what Mat has said (thanks Mat, more crap to buy now !, lol)

If the air box is designed it that manner then yes but the ones in our patrol aren't. The Donaldson style cylindrical housings with the filter arrangement you describe have plastic fins at the entry and make the air travel up to the element before being drawn through it. The sizing is what sucks about them as to get something for our required flow rates it wouldn't fit under the bonnet.

They may clog quicker but they are catching all the dust. I have never had a layer of dust in the bottom of my airbox using a paper element and as above it has to go somewhere.

You get the benefit of the added flow with better filtration and you can still run your snorkel head pre cleaner so it doesn't get dirty as quick.