951 k@n air filter

[coilover944]

i have an 87 951 and im looking to get a k&n. is there any gains in running a cone filter compared to the regular airbox. let me no - thanks

[Techno Duck]

Unless you go with a MAF setup i wouldnt bother with a cone filter.

[flash968]

lol

Wow. How many typos and grammatical errors can you cram into one sentence? Reminds me of a contract I was working on about a week ago. It was so bad I had to quit for the night.

anyway

The answer to the question would depend entirely on the increase in size of the surface area of the filter, and the location, and how they correspond to increased flow and reduced intake temperature. Simple manometer and temperature tests would tell you.

[AaronM]

I wouldn't touch a K&N product if someone offered to pay me. While the products aren't bad, the company itself is absolute *****.

They pay people to go around and create accounts on message boards to promote their product with pre-written drivel; if they get called on it being advertising, they create additional fake accounts to defend the original K&N advertising account.

So wait.... K&N air filters really just lots more dirt in your engine? - AnandTech Forums

While the product itself is on par with any other high-flow filter that sacrifices filtration for flow, the company sure engages in some shady marketing that I really have no desire to support.

[flash968]

that's an odd review - i have actually dealt directly with them, and had nothing but a great experience - they even offered to let me use their dyno for a test, but the scheduling didn't work out

no, i don't work for them, have never had a deal with them, and have no interest whatsoever that would be served by praising them or their products

i see those same "tests" pop up on the web all the time - the problem is that they have absolutely NO evidence that anything getting past the filter does ANY harm whatsoever

basically a paper filter is just a bad design - the marketing teams of the auto manufacturers did a great job at convincing the public that they are the way to go - just goes to show how gullible the general public is - we were much better off back in the 50s with oil bath filters, but they needed more maintenance, were more expensive, and were messy

as for power increases, i have documented proof from controlled tests, of increase on a 968, which had a decent airbox and paper filter to begin with - i have the same results for the jeep that i had, as well as the denali - they do work - it all goes to location and surface area though - also, in about a million miles of driving with their filters over the last 30 or so years, i have had NO resultant wear or damage in any car

K&N has been in business for decades, and of the thousands of vehicles running their filters, i have yet to hear of anybody showing damage as a result of using them when properly maintained

[AaronM]

Originally Posted by flash968

that's an odd review - i have actually dealt directly with them, and had nothing but a great experience - they even offered to let me use their dyno for a test, but the scheduling didn't work out

no, i don't work for them, have never had a deal with them, and have no interest whatsoever that would be served by praising them or their products

i see those same "tests" pop up on the web all the time - the problem is that they have absolutely NO evidence that anything getting past the filter does ANY harm whatsoever

basically a paper filter is just a bad design - the marketing teams of the auto manufacturers did a great job at convincing the public that they are the way to go - just goes to show how gullible the general public is - we were much better off back in the 50s with oil bath filters, but they needed more maintenance, were more expensive, and were messy

as for power increases, i have documented proof from controlled tests, of increase on a 968, which had a decent airbox and paper filter to begin with - i have the same results for the jeep that i had, as well as the denali - they do work - it all goes to location and surface area though - also, in about a million miles of driving with their filters over the last 30 or so years, i have had NO resultant wear or damage in any car

K&N has been in business for decades, and of the thousands of vehicles running their filters, i have yet to hear of anybody showing damage as a result of using them when properly maintained

The only way to get more flow is to have less filtration; that's just how it works. No way around that. No-one is arguing that power gains don't exist, only that they must be accompanied by less filtration.

As high-flow filters go, K&N make a fine product. If you're not intent on having the engine run to 200,000 or 300,000 miles, then you're probably OK. If you change your oil religiously at 3,000 miles you're probably OK. But for the average driver who doesn't change his oil until the light goes on and who never thinks about his air filter, it's just not a good idea.

Still, the fact that the product is good (or even great) as a high-flow, low-filtration filter is not enough to make me want to support a company that pays people to create fake accounts on forums and insult people. If I want a high-flow filter, I'll go with a Mr. Gasket or something.

[flash968]

less filtration is not necessarily a bad thing if the existing filter is doing too much filtration (yes there is such a thing)

all filters represent a resistance in flow which can easily be measured with a manometer

engines draw a fixed amount of air based on their design

flow can be increased by reduction in negative pressure, which can often be accomplished by a reduction in resistance of the filter

as i said, it has to be "properly maintained" - this does also mean that the rest of the things related have to also be properly maintained - if, as you say, somebody is going to ignore things, then obviously this would be a recipe for potential disaster - but then, they should be driving a toyota anyway

i don't know anything about them paying people to do the things you are indicating, which would be illegal, and for which they could get in a lot of trouble - i find it hard to believe, but then, who knows?

i would certainly expect that you could prove those allegations before commenting, and not rely on hearsay, as making such comments, if unfounded, is grounds for a libel suit

[joejoe1]

If using with AFM it may be o.k.. I would not suggest using it with MAF as the oil can contaminate the burnoff wire (thin tungsten wire) and will give incorrect readings. I have not found anything that will clean this off after being cooked on. I had to buy new MAF for my 928. (just my experience)

[flash968]

not if applied correctly - that is a problem that occurred with a couple of 928 guys when they applied too much oil - it is only supposed to be a VERY light coating - if it looks wet, it's too much

for this reason, the aerosol can is much better than the squirt bottle, or even the pump bottle

[wild man]

When I ditched my stock J-boot, air box, and filter, in favor of placing the "flapper box" underneath the IC outlet pipe (the bottom of it needs to be flattened), and using a cone style filter on it definitely DID make a noticeable difference on my 951S, before I went MAF. I have seen recently that my original design HAS actually been copied and commercialized, and is available for sale as a kit. That's a welcome vote of confidence that some of my original designs actually work pretty well. Like they say, imitation is the sincerest form of flattery.

You should see what my 3" K27 feed pipe looks like. In my eyes, it is pure beauty. But looks had nothing to do with it, when I designed it. The design criteria I used was based purely on function, without any though whatsoever, given to cosmetics. I wish so badly, that I could show it off. But unfortuately, I am unable to upload any pics (you should see my exhaust piping mods, too - I think you would be "struck" by them) to this site using my firefox browser (IE is not even on the computer).

If someone could provide me somewhere to upload the pics to, where I could then link to from this site, some of my highly functional "art" could then be viewed by the masses. I'm not saying that I would be expecting 100% praise from everybody. But I think you could be rest assured, that people would be talking!

[flash968]

photobucket?

[wild man]

If I'm not mistaken, that requires a (paid) subscription.

[HondaDustR]

I hate image hosting sites with a passion. Don't know how many times I go searching around for information such as old DIY's where the author uploaded to photobucket and a year or two later the pictures are all dead. If they're worth uploading, they should be part of the post forever. [/RANT]

But anyway, no doubt K&N will flow better, and as a natural consequence, will let more dirt in...pure physics, no tricks. Dirt is abrasive and oil attracts dirt (oil bath filters, right), which means lubricated moving parts in the engine will be exposed to at least some extra wear. Changing oil has only a secondary affect. It will remove the extra ground up dirt and metal particles and prevent them from doing further damage by circulation, but the dirt already does the damage before it even gets past the moving parts into the oil. How much extra wear this actually amounts to will depend alot on driving conditions, filter and intake placement, filter maintenance, and other misc factors. I think it's more of a cost/benefit problem, but nobody has proven it will destroy engines. The logical theory says more wear, though.

My 2c on the issue is that for larger engines, forced induction engines, high performance modified engines, and engines with underengineered stock airboxes, the K&N will make a positive difference. Airbox mods and the K&N filter on the 968 have been dyno proven multiple times. An engine is an air pump...less pumping losses means higher efficiency. I ran a K&N filter for most of the life of my first motor, 60K out of 150K. I have noticed the black dusty residue in the airbox, AFM, and expecially in the throttle body where there's always some oil residue. For the naysayers, the residue was DRY...a properly oiled filter will not shed oil. Less is more! 154K and the motor used 1qt oil/300 miles and the ring endgaps were 1mm plus at autopsy. Don't know how much ring was lost to it's last 30 seconds or so with no oil pressure, but dirt in the intake for 60K isn't good. I went back to the standard OEM Mahle filter, which is much better than your run of the mill Fram or Purolator, and noticed no perceivable performance drops...and I can feel the difference of as little as 10 degree changes in air temp. I decided I want my rebuilt motor to last as long as possible. I put some dabs of grease in the airbox about 1000 miles ago and haven't looked at them yet, but if the results are interesting, I may throw the K&N in and test again.

Fact of the matter is all filters will let some dirt past. -> Air Filter Filtration Test
Whether it's worth it is up to you, but I'd say it's worth a try, especially for a turbo. It makes no difference on a mostly stock 8v NA, but that was expected.

Effectiveness of cone filters depends alot on the circumstances, mostly whether the flow benefits are overshadowed by breathing hot air from the engine compartment. Placement as well as custom baffles or shields to keep out hot air can make all the difference. Don't just plop it right behind the radiator like the ricers do. That's not a "cold" air intake, dude. I'm an advocate for form and function. No useless racer show car bolt-ons.

Oh, no...carried away again. I hope at least it's useful.

[Jrboulder]

Excellent point, HondaDustR
when you think about it, if you just stick a cone filter on a 951 it would be somewhere between the Radiator and the turbo. not very cold.
On an N/A car I would not use a K&N filter because of the intake is in the left fender. Think about all the dust and other crap that can come in from there.

[HondaDustR]

The one big plus in my mind to the K&N, especially with a cone is the sound...OMG!

Best sound I have ever heard was driving to make this video. The camera didn't quite fit inside the airbox without hitting the shutter button and stopping the video, so out with the filter and the cover.
The sound at WOT overloads the microphone in the camera. Really awesome in real life. A cone filter is the best way to get most of the same sound and still run a filter.

Go to about the 2:00 mark to cut right to the good part.

[Aufgeladen944]

I only sell them to people who will actually benefit from one, or to the children who expect mad tyte jdm horsepower gains on their Civics.

Mine came with a K+N box filter in it (dirty), and I had a paper filter. I switched them, and the performance was the same. When I cleaned the K+N filter and reinstalled it, the car seemed to pick up a little more power.

I think it's a slight trade-off of power for filtering. For something with 90hp, it won't make ANY difference whatsoever, so a paper filter is better. For a performance car, it might be worth doing.

I think it also matters on the vehicle. My Prelude sure sounded a lot nicer with the short ram I put in it versus the stock air filter. I didn't expect much in terms of power but the sound was quite pleasing. On our cars, the air filter seems to be in a good place; replacing it with the a cone filter sucking in hot engine air doesn't seem to be the best solution.

[zedsn]

I installed a K&N filter inside my stock 951 air box and about a year later removed my stock air box completely and fabed a bracket to hold up my AFM and installed a cone filter and like the results very much. The cone filter in my opinion is much better.

[wild man]

Originally Posted by zedsn

the cone filter in my opinion is much better.

Well, at least that is not coming from a rice child. Unless the turbocharger is running at it's maximum limit, it really won't have more HP, because drawing air out of a rarified environment is precisely where a turbocharged engine runs circles around an N/A (of the same HP), hands down. But it WILL spool the turbo sooner AND faster, which does translate to BETTER. Not to mention that "sweet" sound emanating from a spooling turboshaft, that is unleashed when a stock box is replaced by a cone setup. Those who haven't done it really have NO clue as to what they are missing. It adds significantly to the overall experience of operating the vehicle. I believe this also applies to any passenger's experience. Nuf sed.

EDIT: Unfortunately, the stock AFM will also block most of this sweet sound.

[AaronM]

Originally Posted by flash968

i don't know anything about them paying people to do the things you are indicating, which would be illegal, and for which they could get in a lot of trouble - i find it hard to believe, but then, who knows?

The IP addresses for both relevant posts in the thread I linked resolve to K&N corporate headquarters. In fact, both "posters" showed the same IP, which indicates that they came from the same computer on the K&N network. So the posts came from K&N corporate computers and during work hours. The first post is a verbatim copy of a post that is plastered across many different forums (this can be confirmed by a simple google search) which makes it obvious marketing material.

Those actions are not illegal, but they are shady.

As for the rest, I agree that for people who want to get that last bit out of their engine a high-flow filter is the way to go. I even agree that K&N makes quality high-flow filters. I just think that, for probably better than 90% of people trading filtration for an extra 5-20 hp (for the full intake, if it's just a filter in the stock box then only 2-5 hp) just plain isn't the right decision. Of course, people are welcome to make their own decisions on this.

In the end, my main objection to K&N is simply that my experience with their marketing methods on the other forum is enough to prevent me from ever wanting to support them as a company.

[J1NX3D]

what did you guys with cone filters do to prevent or minimise heat soak?

Originally Posted by wild man

If I'm not mistaken, that requires a (paid) subscription.

i use imageshack.com

Its free and i have over 48 pages of photos, all tagged, set to public or private, dating back to 2005 when i first started using it. all my photos still work and i use firefox.