People's opinions on K&N

[gerhardb]

I've been reading this thread and I find all the replies to be interesting.

I use a drop in K&N in my 1998 Honda Prelude (H22A4 engine).

UOA reports NO difference than the OEM filter in silicon present.

However, it get the impression that some folks do see higher SI in their UOA.

So there have to be certain factors.

I suggest the factors are probably:

1) Environmental

2) Pre-filter intake differences according to manufacturer design.

Gerhard

 

[digitaldrifter91]

quote:

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I bet you can put a properly sized paper cone filter on a cold air kit and realize the same exact power gain and have better filtration. [/QB]

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i wonderd about this, the 96 GSR integra acura comes with a paper kinda cotton media paper that goes into their airbox and resembles the "cone".

i wonder if u still get the HP increase, yet for one u are removing the air box..that kills the restriction (point of them short ram intakes)...2...will it be equal power than the k & n filter add on?

my friend has this filter, and i havent put it on my car..though id like to try..beats k & n..

 

[goatdude]

Anyone heard of this filter:

Green High Performance Air Filters

 

[Rooster]

The most interesting air filter systems for engines I've seen are on ... combines (as in wheat farming).

A rotating self cleaning chaff screen over the intake, followed by a vortex dust separator, followed by the filter element container. Inside is a very large paper filter element, and inside that is another, smaller, paper element called a safety filter.

There is so much dirt and dust in the air that it's really amazing that the filter takes it all out. The intakes past the filter didn't have a speck of dust that you could see. There was an indicator light in the cab that would start to light up if the differential pressure over the filter elements increased to some point, then it was time to change.

If you told the other farmers over morning coffee that you replaced the paper filter in your $160,000 combine with an oiled cotton one to get better flow, well ...

 

[Steve S]

I must put in my opinion again, I have never seen any thing but paper type filters on the big trucks and forklifts and construction equipment I've worked on,the motors alone cost more than our cars do .What does that say about other style filters,If they were better than paper they would be used.

[ November 27, 2003, 07:49 PM: Message edited by: Steve S ]

 

[AnthonyS]

My in laws farm and have their own independent trucking company. They drive trucks when not farming. I don't think their is anyway they'd ever use anything but OEM filters on their John Deere and Peterbilt equipment. And yes, you really should see one of those filters and assemblies in person to appreciate them.

 

[snowman]

quote:

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Most would agree that an engine needs a fixed volume of air at a given rpm in order to fill the cylinders. You can actually calculate this air demand in cfm. This amount isn't going to vary all that much depending on which filter is in the intake tract based on the limited testing I did.

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The cylinders will always be "filled". Air is compressible so what is of interest is the density of that air that is filiing the cylinder and the corresponding mass.

How is that if the filter used doesn't make much difference to the amount of air getting to the cylinder (even compared to no filter according to your tests - conclusion seemed to be that the filter element is not that significant) then you note (in a different post) that 2 filters in series created a "phenomenal" difference in performance?

 

[AnthonyS]

quote:

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Originally posted by snowman:

quote:

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Most would agree that an engine needs a fixed volume of air at a given rpm in order to fill the cylinders. You can actually calculate this air demand in cfm. This amount isn't going to vary all that much depending on which filter is in the intake tract based on the limited testing I did.

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The cylinders will always be "filled". Air is compressible so what is of interest is the density of that air that is filiing the cylinder and the corresponding mass.

How is that if the filter used doesn't make much difference to the amount of air getting to the cylinder (even compared to no filter according to your tests - conclusion seemed to be that the filter element is not that significant) then you note (in a different post) that 2 filters in series created a "phenomenal" difference in performance?

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More wonderful thoughts from my new #1 fan.

Let's see two filters in series.... okay lets two layers of window tint on one over another. Too simple of an experiment for you? Those are light filters by the way.... How about two resistors in series? electrical power filters.... What about two barb wire fences in series and you are attempting to run through them with your car? A lot harder huh? Analagous? Yes. Simple? Yes. But all of the above answer your question.

Now in my practical case the 2nd filter was of a very small surface area, so much so that it was a major restriction. Adding two filters in series greatly increasese filter efficiency, but it also adversely affects flow.

My opinion is that if you need two filters in series (a filter and a prefilter) that your air filter probably isn't designed very good in the first place. I still stand by my assertion, that if K&N filters were so wonderful (worked as well as reported by K&N) they wouldn't be peddling prefilters like they are now. They are merely trying to profit of the automotive culture in this country and they are doing very well at it.

So really when it comes to K&N and prefilters you have a couple of choices...

1) The K&N filter works superb, and the prefilter is just something they are peddling to make profit (makes them pretty greddy).

OR

2) The K&N doesn't work very well and needs a prefilter (which means most of what K&N has claimed for years is false).

Pick one, doesn't matter much to me either way.

In all honesty, K&N filters are not bad. They aren't bad at all. They just are not the miracle that most including K&N make them out to be. They don't flow a whole lot better, and they don't filter as good as more restrictive filters.

You are still stuck with this reality:

Flow and filtration are inversely proportional. It's a give and take proposition. You can only have one, but not both as K&N claims. Take your pick. I choose filtration, and if I need more flow, I'll make the filter bigger.

 

[mkosem]

I have a K&N FIPK on my Toyota. This has a cone filter. Is there any difference between the filtration of the cones and the panels since the cones seem to have quite a bit of surface area? I would imagine that having more surface area would put less negative pressure on the filtration media and in turn make the filter less likely to pull dirt through. Am I correct in thinking this?

--Matt