K&N Cone Air Filter.

[scrounger]

I ran a stock sized K&N on my Yamaha production two stroke road racer. Even though it was run on pavement except for some of the pit areas, the inside of the air intake was loaded with dust.

Have had much better luck with some of the foam intakes.

I still have a K&N on my 500 single mainly because it was on it when I purchased it. I don't ride it much. At the next rebuild I am going with a foam sock.

[RabbitJockey]

the second test is a bit flawed, he's sucking all the air through a 3" square of filter not even pleated. This has to yield a much higher velocity and pressure than you cold ever hope to achieve with a full size filter. 
Also where one filter has 7 pleats, and another has 15, it won't show a difference despite one having 2x the area.

Yeah that's crap especially hen u see a Mann filter compared to anything else

[bajacalal]

How does it cost more if it will outlast the car?
Mine lists at $25, which adds up to a $46 K&N real fast.

The fact that it's sold somewhere for $25 as an inflated list price is not relevant when we all know that in the real world you can get one for half that.

TD air filters are NOT cheap around here, unless you want some cheap no-name, white box vato-zone, or O'reilly garbage...

I'm convinced I could make a living out of selling stuff like this. Around here they sell the Mahle OC51 filter for the TD engine for under $5 if you know where to look. IIRC you said they were like $10 where you are.

IDK dude.. they run K&N filters on rigs that run the Dakar rally, the Baja 500 and 1000, as well as plenty of other dusty races..

im gonna stand by what i said, if they are cleaned and oiled properly, they will filter almost as much dust out of the air as a paper filter, but with ALOT more flow..

im gonna say that the guy you got your truck from, was an idiot, and probably used compressed air to blow the junk out of his K&N filter, and blew the gauze apart, leaving big holes in the filter media, just letting dust RIGHT THRU..

ive run K&N filters on ALL of my ATVs and motorcycles.. they are often times ridden in VERY dusty conditions.. and ive never had a dirty intake duct, or dirty carb throat either..

But that's different. That's a race. The object is to go fast and with the 1000, just getting to the end is an accomplishment. Who cares if the engine only lasts 5000 miles! It's a race engine and the race is only 1000 miles long! As long as it doesn't suck in a cactus it's the 1000 miles of dust isn't an issue for an engine that's going to be torn apart and inspected after those 1000 miles. It's totally different for a daily driver. you can't compare the two. I want to get to work every day on time. I want to keep my truck for a long time. I don't want to rebuild my engine. Fortunately it was a low mileage truck even with the dust. For those reasons, I will take a filter that does a better job of filtering the air, even if it takes away a few HP and even if costs more in the long run, I want the best filtration, not the best air flow or lowest price.

But as I said, at least I think I said, K&N filters do have a place in the automotive world. I forgot to mention that I had one on my FIAT spider. And that was after I took it off the Jeep (but not the same filter). That car wasn't a daily driver. A few more specks of dust didn't matter. But over 100 or 200 thousand miles on a daily driver that does matter. On a boat, they're fine in my book. Even on a dirtbike, a K&N filter is fine, because how often are you riding the thing really? A few hours a month maybe? But to put one on your truck that takes the dirtbike to where you ride it? Hell no.

As far as the previous owner of my truck? I have no idea. I never blew mine out with air or brake cleaner, but the Jeep did get dust in the intake, although fitment with that filter was in issue too, something else I've noticed with their filters. They're made of wire mesh and rubber, they don't squish nicely into an airbox, at least some of them don't, so I think you can get leaks around the edges of their filters.

[tyb525]

Something that no one has mentioned, is when dust is found in the intake when using a K&N: Are all connections airtight? It seems like a very good possibility that air is getting in somewhere besides the filter. I have seen many different airboxes that don't even look air tight.

Also we don't know how they were oiled/if properly oiled at all.

[homerj1]

Not to complicate things - but what about a Honda s2000 paper cone filter?

http://www.canadapartsonline.com/air-filter/honda/s2000.html

From what I can find Ford engines and some Chev vortex engines also use a paper cone- type filter.  Maybe a trip to Napa might be in my future?

Also found this '88 to '91 Honda Prelude Air Filter

update: http://mymiata.paladinmicro.com/#DIYIntake
 

So build an air box and change paper cone filters?

[homerj1]

Not to complicate things - but what about a Honda s2000 paper cone filter?

http://www.canadapartsonline.com/air-filter/honda/s2000.html

From what I can find Ford engines and some Chev vortex engines also use a paper cone- type filter.  Maybe a trip to Napa might be in my future?

Also found this '88 to '91 Honda Prelude Air Filter

update: http://mymiata.paladinmicro.com/#DIYIntake
 

So build an air box and change paper cone filters?

[745 turbogreasel]

I have  cones that I won't use, as the area is less than my stock  rectangle.

[scrounger]

A simple test would be to put a vacuum gauge tapped into the inside of the air box (before the turbo) some place and see how much pressure drop there is.

I have a feeling that you might need a very sensitive unit to detect the pressure drop through a stock air filter.

Also picking up the air from behind the radiator would raise the temperature of the charge, decreasing the amount of oxygen that the engine actually gets.

[R.O.R-2.0]

Paper filters out smaller particles and flow less air, are cheaper, and aren't reusuable.

K&N filters slightly worse than paper, flow more air, are reusable, and are more expensive initially.

Pick your poison, I don't think it as big of an argument as people on the internetz make it out to be. Kind of like the argument whether amsoil is actually good or not. I really don't care either way on the matter, I would run either filter and I have run both kinds on various vehicles and haven't had problems with either.

Anyone else notice that first link seems to be biased towards ac delco? their products have always been viewed as pure crap by every mechanic I've known.

yes, i definitely noticed..

[8v-of-fury]

http://forums.tdiclub.com/showthread.php?t=290373

[homerj1]

http://forums.tdiclub.com/showthread.php?t=290373

Thanks for the link!

[tyb525]

Some of those tests are hard to believe, like someone is getting incentives from the competition...

[8v-of-fury]

The competition being OEM paper air filter manufacturers? lol

[theman53]

What isn't stated is that you can "tune" your car to the filter and intake setup. If you bolt on a filter setup and do not change anything fueling wise, nothing will happen. On my car I could run the fuel screw another 1/8 to 3/16 turn with the same EGT as before. If you have a computer car and you don't tune it, the filter will not add more fuel. It is just like a header or intake or muffler or anything that adds or reduces engine flow. You must tune accordingly. If you have a turbo with the potential to flow enough for 250HP but your pump settings are only ever going to give you enough fuel for 150HP you will never have 250HP. Same with filter. Most all of those tests were NOT maximized for the air flow the filter could give.

I tried this myself with the TD airbox stock filter and the K&N pannel filter. The ammount of EGT and black smoke was crazy if I tried to keep the K&N settings with the stock Mann.

[R.O.R-2.0]

What isn't stated is that you can "tune" your car to the filter and intake setup. If you bolt on a filter setup and do not change anything fueling wise, nothing will happen. On my car I could run the fuel screw another 1/8 to 3/16 turn with the same EGT as before. If you have a computer car and you don't tune it, the filter will not add more fuel. It is just like a header or intake or muffler or anything that adds or reduces engine flow. You must tune accordingly. If you have a turbo with the potential to flow enough for 250HP but your pump settings are only ever going to give you enough fuel for 150HP you will never have 250HP. Same with filter. Most all of those tests were NOT maximized for the air flow the filter could give.

I tried this myself with the TD airbox stock filter and the K&N pannel filter. The ammount of EGT and black smoke was crazy if I tried to keep the K&N settings with the stock Mann.

my 86 GTI is tuned to run a K&N panel filter with a modified lower air box..

i notice the power difference if i switch back to a stock Mann diesel filter..

it also gets about 1-2mpg LESS with the Mann filter..

my K&N costs about as much as 6 Mann filters..

ive basically paid my K&N off, just in filters..

its pretty dusty around here, i would have to replace a paper filter atleast a couple times a year..