Outer Limits 4x4 Board

It needs to be said again. Krap&N air filters are crap. This has become my personal crusade, to wake people up to the fact.

Case in Point:
A certain F1 team were using Krap&N air filters. DURING 1 RACE, THE ENGINES FAILED ON BOTH THEIR F1 CARS!!!

Needless to say, they are now using conventional fibrous filters from a different filter manufacturer, even though the conventional filter has double the pressure drop of the Krap&N, and more pressure drop means less HP. I have a filtration efficiency curve for the exact Krap&N filter used, but am not permitted to post it for confidentiality reasons. But the bottom line is THE FILTER WAS SO BAD IT LET IN ENOUGH DUST TO KILL 2 ENGINES - in only one race ON TARMAC. This was an oiled cotton filter, almost the same as you can buy off the shelf (except this one had a carbon-fiber housing. If you have one in a 4x4, imagine what is getting into your engine.

IF YOU USE KRAP&N, YOU HAVE ROCKS IN YOUR HEAD, AND YOUR ENGINE.

That is all, rant over. Normal programming will now resume.

EDIT, OH, and Greetings from Madison WI (USA, near Stoughton WI). All the people here know that Krap&N are Crap too (who knows why?). Here is a hint, I got to play with a 15L, 500HP diesel yesterday.

here is a link that was posted in the mitsi forum few weeks back, regarding K&N air filters not being very good. interesting reading !! substantiates your claims !

http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

cookie monster

I ordered one in for a guy at work and when I had a close look at it there is no way in hell I would put one of them in any of my vehicles!
When held up to the light there is holes just about big enough to let grains of sand though let alone dust.
I reckon a peice of fly wire would filter as good.
But yeah I can see why they flow well
Paul.

These high flow filters are not doing your engine any real benefit. They can cause the engine to run lean and move your torque curve to where you don't need or want it. This starts the "chasing the tail" syndrome associated with modifying cars. Soon you have replaced the exhaust and changed the cam and blah blah blah.

Now your car is loud and attracts cops. You never anticipated the huge fuel bills. Not to mention the bottom end which is under huge strain from the increased HP. Before you know it, you'll need to modify that too.

EDIT, OH, and Greetings from Madison WI (USA, near Stoughton WI). All the people here know that Krap&N are Crap too (who knows why?). Here is a hint, I got to play with a 15L, 500HP diesel yesterday.

bloody hell Ben, that's a bit obscure, give us some more hints

cookie monster wrote:here is a link that was posted in the mitsi forum few weeks back, regarding K&N air filters not being very good. interesting reading !! substantiates your claims !

http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

cookie monster

cookie monster, just between you and me, I think that link ended up in the mitsi forum after Isuzurover posted it in an earlier thread here.

What goes around, comes around.

Scott

cookie monster wrote:here is a link that was posted in the mitsi forum few weeks back, regarding K&N air filters not being very good. interesting reading !! substantiates your claims !

http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

cookie monster

Brilliant article that! Very interesting and surprising test results too!
Think I'll hold off on the crap'n'en filter now, I travel on dirt a lot.
The Uni-Filter results looks like a happy medium though.

sudso wrote: Think I'll hold off on the crap'n'en filter now, I travel on dirt a lot.
The Uni-Filter results looks like a happy medium though.

But the Unifilter rated highest in the "Accumulative Gain" section, which is the total amount of dirt that passed through the filter during the test.

So this filter let it the most dirt... why would you still use it?

Paper filters all the way!

i was doing a service at work the other day and this falcon had an ss inductuion set up and one of there filters same as krap&n and courious as i was i opend it up for a look and inside the hose was all dusty i could wipe it out with my finger and that was on a xr6 think about how much dust it deals with in convoy on a dirt road

rick130 wrote:

EDIT, OH, and Greetings from Madison WI (USA, near Stoughton WI). All the people here know that Krap&N are Crap too (who knows why?). Here is a hint, I got to play with a 15L, 500HP diesel yesterday.

bloody hell Ben, that's a bit obscure, give us some more hints

Well the engine I was playing with was made in the US, by a company that starts with C - is that enough? They have a division that makes filters that is based in stoughton WI, the filter brand starts with F, and are used by lots of trucking companies in OZ.

If anyone is interested, I would be able to make a cleanable filter that has a pressure drop near a Krap&N filter, but the efficiency of an OEM filter and still be cleanable. Would anyone be interested???

ISUZUROVER wrote:If anyone is interested, I would be able to make a cleanable filter that has a pressure drop near a Krap&N filter, but the efficiency of an OEM filter and still be cleanable. Would anyone be interested???

Yes. $$$?

$$$ will depend but Yes.

Proton 1.6 and zook sierra

I thought the dust issue with the KandN filters was common knowledge, I’m sure it says in on the box

Its common knowledge among us...
But they still claim:
"Designed to increase horsepower and acceleration while providing excellent filtration "

How can it be classed as excellent filtration when it is worse than a standard element? lol

K&N only has claims of performance, and this is seen in thier testing section on thier page.. They only do flow tests and pressure drop tests.. no filtration test

HotFourOk wrote:Its common knowledge among us...
But they still claim:
"Designed to increase horsepower and acceleration while providing excellent filtration "

How can it be classed as excellent filtration when it is worse than a standard element? lol

K&N only has claims of performance, and this is seen in thier testing section on thier page.. They only do flow tests and pressure drop tests.. no filtration test

So, in theory, I could go out and fab up some fancy plate, with mesh, and sell it as a 'performance' filter, thats 100 times better than K&N and sell it to all the rice out ther ..... could prolly get away with it on ebay for a while

:Flame suit is now on.

I use a K&N filter on my 22r. I am happy with it, No dust comes in. I have used it for years. If i was doing a 4wd convoy on dirt roads i wouldnt dare use it. Its not what there were made for, That is a precleaners Job.

Lower down torque , more throttle response ( small) and better overall engine drivability. rtunning a large filter on a small motor means increased service intervals, Meaning less costs and service time.


If i was using the 4runner for a lot of offfroad work, I would change this setup with an airbox,etc. But im using it for more street work atm.

I am happy to wear a flame suit with my K&N filter . So many comparos are rigged and have varying reults based on (Lab results) and unsuited Real world " Scenario's" . I havent looked at this one due to this fact.


Anyways, Im about to get shot down in flames, So if i dont reply its because my flame suit is working very well

ive seen dyno results that show the vechiles performance was worse with the k&n filter than the original paper style

and as one turbo manufacturer said in regards to any foam style air filter
''ever tryed to breath threw a sponge ''

Ever tried to breathe thru a newspaper?

That doesnt work either so paper filters must be crap too.



Lol, even so I'd never put a K&N on anything of mine again.

HotFourOk wrote:

sudso wrote: Think I'll hold off on the crap'n'en filter now, I travel on dirt a lot.
The Uni-Filter results looks like a happy medium though.

But the Unifilter rated highest in the "Accumulative Gain" section, which is the total amount of dirt that passed through the filter during the test.

So this filter let it the most dirt... why would you still use it?

Paper filters all the way!

tanks hot4, Just looked at the test again (with my glasses on!)
Looks like I'll stick with paper filter, specially since I want a snorkel too.

pongo wrote::Flame suit is now on.

I use a K&N filter on my 22r. I am happy with it, No dust comes in. I have used it for years. If i was doing a 4wd convoy on dirt roads i wouldnt dare use it. Its not what there were made for, That is a precleaners Job.

Did you read the first post? The Krap&N was so bad that 2 F1 engines failed during one race on tarmac! The race track had some sand on the track, the sand was getting sucked in the intake and hitting the filter hard enough to penetrate the filter!!!

I am seriously considering making a "high performance", cleanable filter that actually works. I don't know at this stage if I would get it made myself or go through one of the major filter manufacturers. The fibrous media I have in mind is extremely expensive, but the media only makes up a small component of the filter cost, so, overall I can"t see it costing more than a Kreap&N. Further expressions of interest are welcome...

Make some, test some and let us know how they go.

Me and a mate fitted one yesterday, he dropped the 12mm ring spanner just as I pegged the engine to 5000 from the carby to get some fully sick induction noise happening. The spanner bounced straight of the foam filter didn't get sucked in at all! I think you fella's are all full of crap, did I mention the fully sick induction sound

need to keep things in perspective too..... F1 cars run at 20,000rpm, and draw enormous amounts of air through their intake. You would suck a house brick through a K&N at those revs....could be worse... they could have used a FINA (sp) filter don't get me wrong, i'm not disputing whats has been said, i don't use washable filters. Been told all along to always use the paper filters.... cheaper to change regularly. Also heard people say they use and love K&N filters...... each to their own i guess

ISUZUROVER wrote:

pongo wrote::Flame suit is now on.

I use a K&N filter on my 22r. I am happy with it, No dust comes in. I have used it for years. If i was doing a 4wd convoy on dirt roads i wouldnt dare use it. Its not what there were made for, That is a precleaners Job.

Did you read the first post? The Krap&N was so bad that 2 F1 engines failed during one race on tarmac! The race track had some sand on the track, the sand was getting sucked in the intake and hitting the filter hard enough to penetrate the filter!!!

I am seriously considering making a "high performance", cleanable filter that actually works. I don't know at this stage if I would get it made myself or go through one of the major filter manufacturers. The fibrous media I have in mind is extremely expensive, but the media only makes up a small component of the filter cost, so, overall I can"t see it costing more than a Kreap&N. Further expressions of interest are welcome...

Yes i did read it. But they arent the same filter as i bought from supercrap auto, IS IT

Same company yes, but different model. My car has never been on a dyno, But as i said "Drivability" . The biggest performance variation is the nut on the end of a steering wheel, Not a air filter. I know people who have run them on there bikes for years. So, If a baby 4 cyl engine can stay clean, then why wouldnt my 22r providing i maintain the filter.


Now, I do have to say that 4wd systems suck, So maybe our efforts are better pointed in that direction

ISUZUROVER wrote:Did you read the first post? The Krap&N was so bad that 2 F1 engines failed during one race on tarmac! The race track had some sand on the track, the sand was getting sucked in the intake and hitting the filter hard enough to penetrate the filter!!!

Ben, I'm not doubting that K&N are suspect, but I think you're getting carried away with this as an example. Now, I'm sure you'll correct me if I'm wrong (you usually do ) but don't F1 cars use ram induction? So the failure mode in this instance (sand particles punching through a filter with (effectively) 200 or 300km/h of momentum) isn't likely to be an issue with my snorkel fed Pajero breathing through a U-bend.

This also helps complete the picture for me. I couldn't understand how an F1 team could choose a filter which didn't filter adequately. I suspect they tested filtration efficiency, and were happy with the performance they were expecting over a 2 hour race - but they didn't anticipate this failure mode.

Like some others have said here, when I remove my K&N and check upstream in the intake, I'm not finding dust - unlike some others are finding. So I'm happy to keep using my K&N until you can come up with something better again.

Cheers,

Scott

Washable oiled type filter rely on the oil to hold on to the dirt when a foam element filter is full of dirt i wont cause a restriction the oils capacity to retain the dirt it full so it lets the dirt through. Washable filters need to be cleaned anf oiled regulary. I used the Unifilters for many years then went back to paper element for piece of mind as i just didn't trust the oiled foam. One other thing that comes to mind is that a few years back it was identified on the hitech fourstroke dirt bikes were having big problems with valves receding and was mainly in Australia this was attributed to Australia being one of the dryest continents and we have the finest dust here compared to the rest of the world. The bikes speced for sale in Australia have a different filter material to capture the finer dust. I think it was the last ISDE in Australia had a large number of international teams suffered engine failures attributed to the fine dust we have.


My ten cents

Wally

Definately interested but is this going to be a universal fitment filter or will there be a range of sizes? I also know of someone that tested some filters in their lab at work and has now reverted to paper. The other styles improved performance but the filtration was worse.

OK so I use a K&N 3" pod filter at the moment. What should I use instead? Keeping in mind that I don't have an air box....

NJ SWB wrote: Ben, I'm not doubting that K&N are suspect, but I think you're getting carried away with this as an example. Now, I'm sure you'll correct me if I'm wrong (you usually do ) but don't F1 cars use ram induction? So the failure mode in this instance (sand particles punching through a filter with (effectively) 200 or 300km/h of momentum) isn't likely to be an issue with my snorkel fed Pajero breathing through a U-bend.

In the end I dont think the speed the sand is sucked in makes any difference, it's the fact that it gets sucked in at all that is the problem.

I would agree - airspeed through a filter can be pretty high, regardless of road speed.

I would never touch a oiled cotton filter after seeing how much dust was in the inlet of Greg's 660cc sierra after about 12 months. He was very careful with servicing. Let's just say lucky it wasn't a diesel. He now runs a paper 1.3 sierra filter and his next car will be running a stock Jimny airbox.

Fair point about the pod though - My next project will most likely require a pod (in a box, fed through a reversed bonnet vent) and I don't want to dust my engine. I suppose I could build the box to take a panel, but the pod would be easier to shield from splashes.

Steve.