Do K&N filters increase power? There expensive! They use oil to trap dust apparently? That sounds like a nightmare to upkeep..
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Do K&N filters increase power? There expensive! They use oil to trap dust apparently? That sounds like a nightmare to upkeep..
well they increase air flow, in turn giving a little more power.
very easy to clean from the inside out, let air dry, then re-oil.
i have two filters that i can just swap and clean and re oil when ever i feel like it.
they are a little pricey but you only buy once and just keep reusing it.
i just replace after any dusty trip and at service intervals.
I have a K&N filter. They work well and any increase in air volume is welcome.
Although our last Dargo trip was so dusty and when I got home and looked at my filter I couldn't believe it, I won't run a K&N filter on a trip like that again, I will buy a paper filter and throw it out after the trip.
Those trips is when you need a snorkel sock..
I use both... for trips away I use a paper filter and keep a spare but for around town or highway trips keep the K&N in.... found the K&N gets so clogged up on real dusty trips.
I should have taken a photo of my filter... it was disgusting!Quote:
Originally Posted by Bloodyaussie
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.Quote:
Originally Posted by Winnie
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.
I agree with nissannewby on this.
I don't quite see the logic you blokes are using in taking out a filter that is proven to be filtering the dust out and putting in one that is letting the shit in when you go into dusty conditions?
Yes, you can throw the paper one away but, Jeez Louise, think of all the poo your engine has swallowed. Logically you should be doing it the other way around
Hmmmmm.......... !!!!!!!!!!!!!!
Interesting... thanks for that Matt.Quote:
Originally Posted by nissannewby
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.
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?Quote:
Originally Posted by Clunk
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
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.Quote:
Originally Posted by lhurley
Thanks mate, superb explanation as alwaysQuote:
Originally Posted by nissannewby
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..Quote:
Originally Posted by nissannewby
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.
Well.....you have been the first car in the convoy lots, and as you know, the last car gets soooooo much more dust, mmmm, perhaps i need to learn where im going so i can lead more often (lol) :hpfredgeorge1:Quote:
Originally Posted by nissannewby
Mine is a 4.5L and so runs a slightly different configuration air box from factory, the air box sits on a weird angle too.
Seeing Matt only half answered your questions I will add in your post.
Do the K&N filters come with a seperate outer dry pre filter that slips over the main oiled filter ? (like uni filters)
No the purpose of the fluted design is surface area a uni filter is a oil foam construction they work well but do suffer air flow compared to a K&N due to element surface area.
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 ?
Not really its more to do with element surface area with respect to element size. There is many positives with the Donaldson one being they filter well when sized correctly to flow capacity actually down to 4 micron when air speeds are below 4 metres/sec. They are a big element so service life is very good. BUT having tested many Donaldson's on a flow bench and no dust so perfect conditions they flow very well to their stated flow capacity. But they were designed for heavy machinery in low rev or constant rev engines, they were not designed for fast flexible ever changing high revs engines. They fail quite badly at air accelerations imposed by our turbo charged high rev diesel engines which can require air flow accelerations from 50 cfm to 500+cfm in a few seconds. The Donaldson type air box can see very high restrictions when this type of accelerations happen which will severally impede your turbo to spool hence driveability which is our main aim in a modern car or 4x4. In saying that they do a lot better job at accelerations and filtration than a ZD type air box with any type of element fitted..
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 ?
The dust you see in the outside bottom is fine dust or dust particles fallen off the element but the amount is tiny compared to what has been collected in the flutes of the paper element, the K&N collects all particles in the core of the element against the oiled cloth median. For a good design air box you will see fine dust particles in your induction system after the element if you have any oil in the post element tubing you will see a lot of dust but for a good designed air box these particles will be smaller than 7 micron which is proven fact will do no damage to the modern engine. K&N has a oil median so you will get oil spread through out your post element induction system so this fine dust will be collected on this oil, it looks bad but these particles are less than 7 micron so no damage to your engine FACT. (many 4x4 margarine article writers have no idea including the very best of them) Now sadly our ZD airbox cannot and will not keep air accelerations air speeds below 4 meters/ sec so the dust you see inside your post element are particles well above 7 micron. I have only done one field test on a ZD air box with a sticky 30x30mm test sample in the air box elbow. These tests are damn expensive hence only one test but that test piece was a 10 minute run behind an another 4x4 on a dirt road following quite close the sticky had 11.5% of it test sticky area with particles above 7 micron and some of those particles were as large as 80 micron. So in my learned opinion the ZD airbox is total fail with a paper element.
I thought the K&Ns would actually visually clog quicker in dusty conditions because its sticky and won't let go of any dust ?
Yep you have the right idea "wont let go of any dust" that's exactly what we want. So what if you have to clean it a bit more often, but just because it looks clogged or terrible that doesn't mean it isn't doing it's job as intended. You will feel power loss when it is clogged or fuel usage increases..
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)
Maybe you should believe your eyes and not your heart with elements. oh I forgot the TB45 airbox is only slightly better than the ZD system its flow capacity to .5 inchers of mercury is only slightly more, it still has the same issues with air speeds, lol but its a TB45 haha it may not have the ability to produce 4 metre/sec air speeds hehe
Awesome Oldmav, thanks for taking the time to explain that better for me :cheers:
Ive used K&Ns in my performance road cars for years, discussions ive heard/read, put me off the idea about them for dusty off roading , (campfire old wives tales I guess) as ive done pretty much zero testing myself, id thought what people said about not using them had made some sense at the time, the fact you have actually tested it properly in real world conditions is excellent.
Yes, but unlike a ZD30, at least the TB45 has a better chance of staying "together", long enough for dust ingestion to become a problem ! :blowup: (haha)Quote:
Originally Posted by OldMav
.:wink:
Also remember my comments are directed to the ZD air box and its paper element not all paper element boxes, many work very well, Paper or K&N With a properly designed box.
The K&N has had a lot of bad press over the years mainly from 4x4 margarines writers who made a judgment using their eyes and not their brain and some simple basic research.
To be very honest the K&N isn't the be all to end all they do have faults one being under oiling and over oiling which can interfere with maf sensors dramatically causing limp mode issues to but name a few.
So is that purely from user error over/under oiling, or from oil sag/build up at the lower part of the filter over time ?Quote:
Originally Posted by OldMav
User error only..Quote:
Originally Posted by 04OFF
Oldmav, I have the Patroldocta ZD30 style airbox on my TD42 with a K&N filter, is there a better option for me? I don't have a lot of room there with dual batteries either.
Fatz fabrication may have an option.Quote:
Originally Posted by Winnie
I have tested that particular air box option I wont write the name for obvious reasons, but they are hardly better than a ZD box, The first thing you learn with air boxes is the 30mm minimum rule for all round element clearance, Then you need some system of diffusion at the inlet point to force the air to use all the element for filtration. the FATZ or 4Bfab or any of the new panel element boxes now days are a good option which can be fitted to allow the second battery.Quote:
Originally Posted by Winnie
So what is the benefit of those air boxes??? I have thought they were a big pain in the arse as they take some time to open up to inspect or do maintenance on and have seen many a member not be bothered to open it up to inspect due to not being bothered..Quote:
Originally Posted by OldMav
Now I have a stock tb42e airbox that has had the blow by fitted for gas but I no longer run gas... is it worth putting back to stock?
They look shiny :). They are ok until you put the filter in then there is not enough room for it to all work correctly.Quote:
So what is the benefit of those air boxes???
They do look good... hahaha.
Would there really be much benefit in getting an airbox like Oldmav suggested before for my setup, or is it more for the boys running bigger numbers?
Yes. The less restriction in your intake system the easier your turbo can work. Most people when they go to one of options suggested need to reset their boost as it generally increases with the less restrictive setup.Quote:
Originally Posted by Winnie
Air filters are overrated!! Lol
I will try and explain this a little. I have already pointed out some of the things that are issues with a ZD box but don't get confused with my comments. I am somewhat a idealist so I always chase the 1% improvements. Its just that the ZD type air box design is very restrictive even for the ZD engine. Its not just the air box either the STD tubing from air box to turbo is terrible even the std snorkel tubing through the GU guard is terrible, So very simply the turbo tubing is a 1%er the guard tubing is a 1% er as you can see these 1% improvements all add up so there is good driveability improvements here not Kilowatts but torque rise and how quick that torque curve rises due to the turbos ability to spool faster and the turbo shaft speed or revs can stay more constant. This stuff you can feel in the seat of your pants even though it only improves KW marginally, torque changes is the stuff you feel and makes your rig nicer to drive due to flexibility or in this case engine response.
So Winnie there is considerable improvements by having a free flowing induction system it allows the full potential of your engine to be realised. But even for your patrol doctor there are improvements to be had by a simple element change. I will post a comment from another forum which a member took on my pointed suggestions to see what would happen.
Quote follows. using a patrol doctor Air Box.. He is also a member of this forum..
"well, thought I would have a play around with different filters in the ute...
went from a Ryco A1412 to a Ryco A1504 (which is the filter that suits the 3L diesel rodeo's) and happily got some positive results.
my MAX EGT's have reduced from 550degC to 500degC.
my max boost has increased from 15psi to 17psi.
from eye, rpm and boost response seems to be a touch more responsive.
from the seat of the pants, seems a touch better then previously.
happy with that result."
So you see a simple element change has a considerable effect to driveability which should suggest to you how fail that air box really is without even considering filtration issues due to air speeds. Imagine if he had a FATZ or a Millweld or a simular panel big HP airbox with ideal induction tubing. I call these improvement things 1%ers because they increase driveability and response which is the stuff we feel and want for our rigs not outright bragging rights that big KW numbers have. Even though to get higher torque which is the stuff we feel we need KW to maintain this power, hence why I have big numbers. Big KW numbers are easy to get, more fuel more air pumped = big numbers, I broke the 200rwkw value April 1990 24 years ago but you couldn't drive the bloody thing on the road it was madness to drive. Its taken 24 years of stuffing about to get real improvements and I am still playing.
I've used K&N filters in most of my 4WD's and love them , But i haven't put one in the Patrol because the other K&N's I have used have to be sprayed with oil after cleaning and didn't want to cover the MAF sensor in oil !
Yeh, and fark they are spencive for a 4.5L !
I'll give ya a $100 for your rear bar if that helps lol :)Quote:
Originally Posted by 04OFF
Haha, that wont even cover the cost of the lights Stevo ! :tease:Quote:
Originally Posted by gaddy
It's all a bit of philosophy and commercialism I reckon.
Back in the early, mid 20th.C. you serviced your wheels and an air filter had a foam element which you cleaned with a kero bath, dried , reoiled and but back. Lasted damn near forever and worked a treat.
21st.C. and the vast majority don't know where the bonnet release is let alone what's in there. ALSO, MOST IMPORTANTLY, the manufacturers want you to buy new every time, all the time. Answer?. Replaceable paper air filters. Dead quick, dead easy, dead profitable. Don't work as well but shoot, there's money in a replacement engine in quicker time anyway.
As always, it's a matter of time, knowledge, effort and convenience. Bit like women really. The late models look real good but expensive whilst the old one's really, really reliable and you know what you're doing and where you're going.
Cheers
Col.