K&N Air Filter Installation?

[JKirk]

I'm about to go pick up an air filter for my car tomorrow at Advance Auto Parts since mine seems to have a bunch of bugs and dirt in it. Will it be worth the $50 for it? Also, what's the installation like? Any guides or personal experiences. TIA!

PS: This is on my '03 Legacy sedan.

[Wiscon_Mark]

Well, it's 50 bucks because it's reusable. You clean it out, and then re-oil it, and use it again. It's worth 250,000 miles if you use it that way.

Changing a filter out of an airbox is very straightforward, don't worry about that part.

[JKirk]

Well, it's 50 bucks because it's reusable. You clean it out, and then re-oil it, and use it again. It's worth 250,000 miles if you use it that way.

Changing a filter out of an airbox is very straightforward, don't worry about that part.

Yeah, it said washable. I have quiete a few bugs and a lot of dust in mine so I'm thinking about buying this to improve my mileage and maybe a little HP would definitely be a bonus.

[Wiscon_Mark]

It really won't give you any more power. The paper filter makes up less than 1% of the total restriction in the intake system on our cars.

[JKirk]

Anyone else recommend getting one? I'm going to pick this up tomorrow if I decide on getting it.

[ooberdoob]

i reccomend against it, reguardless of what people say, if more air gets through more dirt does too.....

many many forced induction guys are using stock filters :-?

i have a K&N now, next car i have won't get one though.

up to you, are you gonna drive the car into the ground or sell it in a while?

if you're gonna cycle the car out, then yeah K&N.

[scottzg]

its 30$ down the toilet if you ask me.

[JordanIsHere]

its 30$ down the toilet if you ask me.
Care to explain why? I need a new air filter too so I'd like to hear some opinions!

[scottzg]

because the filter is an insignificant restriction and those oilcloth ones let more particulates in.

[SHOfast]

Just get a regular filter, KN are not worth it, you will not feel any power gains, plus there have been some reported problems.

I know some come over oiled and have caused a few MAF sensors to fail, but regardless, there are no proven gains.

[Huffer]

You'll have no problems with one, especially on a MAP based intake (which yours is).

I have one on my MY99 Impreza, and it was worth the money just in replacement filters.

They do come over-oiled from the factory, so get a paper towel (a few) and dab off some of the oil.

I've had mine on the car for several thousand miles, did some offroading (dusty trails) and no problems with the car.

Just because something flows better doesn't mean that it filters worse... though that is often the case.

Given that a K&N costs $30-40, and the recharge kit is $10... OEM filters are $10...make up your own mind.

[jey]

I don't know if anyone else has experienced this, but I have had to quit using the K&N filter after I did the snorkus removal. After removing the snorkus, my K&N would get dirty extremely quickly and leaves, seeds, and pollen would get caught up in it and I found I had to wash it and clean it about every month at least! I put a regular air filter back in and it doesn't get dirty quite as quickly - I only have to replace it every 6 months or so. I realize this is a pretty unique situation as my air filter is pretty much completely exposed in the wheel well... didn't know if anyone else experienced this.

[Wiscon_Mark]

When I had my RAM air tubing in, my filter got dirty rather quickly too. Mostly bugs, but it was pretty gritty too.

[Zubi Zubi]

Hey JKirk,

I run a free flow (A'pexi) filter in my standard airbox ('93 GX) and have run these oil type filters (including K&N and BMC) on every car I've ever owned and have never, ever had any problems or an AFM fail. Not once. My previous '91 Liberty GX has over 250'000km on it (as my younger brother now owns it) and it uses a pod and still has the original AFM on it.

The main reason is because I've always been careful to use a very, very light cover of filter oil on the element. The reason most people have problems with AFMs is simply because they oil the **** out of the filter element, when all that is needed is the lightest of sprays.

Remember that the size of the particles you're trying to capture in that filter is microscopic, so an almost invisible sheen of oil is all that is required on the filter element (NB its actually the oil that traps the dirt, not the filter. The filter is the bit that lets the air through :wink: )

Flat-panel filters also only need the surface that comes into direct contact with the intake to be sprayed, not the whole filter. So the AFM shouldn't really be effected in any way as its on the other 'side' of the flow.

I'd recommend getting into the routine of cleaning the AFM with contact solvent everytime you clean your filter anyway, just to keep the whole system clear of contaminants. Takes seconds and works very well.

Forget about power increases, as apart from the noise you should find that driveability and response are improved (you HAVE performed the snorkusecktomy? :razz: ) Economy may also benefit thanks to a better flowing system.

I'd also save your $$ and not worry about the special 'cleaning kits', as a wash in bucket of warm soapy water, a thorough rinse and letting it drain & dry completely in the sun works just as well.

Follow these simple steps and be diligent in cleaning and (VERY lightly) oiling your filter and you should have many trouble-free times ahead!

[rougeben83]

I've used it in the 3 cars I've owned...no problems in any of them. As previously mentioned it's the cleaning and oiling that gets a lot of people. I've run the KN on my Legacy in 2 really dusty rallycross events now, and 2 1200 mile roundtrips through PA (which gets plenty of bugs) with a 3" straight pipe from the air duct to air box and the filter; its still in good condition.

The more miles you put on it, the KN filters better. The crud it traps actually helps it to filter more stuff down the line. So literally, don't clean it too often (like maybe once a year, or 30k-40k miles, suggested is like 50k) or you won't be letting the filter do its job properly.

Otherwise...the flow isn't really affected that much with it vs. the paper. I didn't notice such a big increase in mpg. The snorkus and plastic pipe are bigger restrictions. I did it just because I already had the cleaning kit and got mine used for $25.

Oh and don't listen to the MAF bitching...your car has a MAP :wink:

[rougeben83]

I've used it in the 3 cars I've owned...no problems in any of them. As previously mentioned it's the cleaning and oiling that gets a lot of people. I've run the KN on my Legacy in 2 really dusty rallycross events now, and 2 1200 mile roundtrips through PA (which gets plenty of bugs) with a 3" straight pipe from the air duct to air box and the filter; its still in good condition.

The more miles you put on it, the KN filters better. The crud it traps actually helps it to filter more stuff down the line. So literally, don't clean it too often (like maybe once a year, or 30k-40k miles, suggested is like 50k) or you won't be letting the filter do its job properly.

Otherwise...the flow isn't really affected that much with it vs. the paper. I didn't notice such a big increase in mpg. The snorkus and plastic pipe are bigger restrictions. I did it just because I already had the cleaning kit and got mine used for $25.

Oh and don't listen to the MAF bitching...your car has a MAP :wink:

[rougeben83]

ugh...dammit. how do I delete double post? :-?

[JKirk]

Thanks for long and informative posts, both of you. :) I had to order the filter at the local Advanced Auto but I got busy and couldn't pick it up so they sent it back to VA. I really want to do a snorkesecutmy and then replace the air filter but I keep putting it off since I'm not sure where to get the piping. :(

[Zubi Zubi]

That's also my next step JKirk, to get a piece of piping made up from the airbox to the intake manifold.

Unless you can get a kit (not easy here in AUS) any good exhaust shop will be able to bend a 3" piece of piping to fit. Then all you need are some clips and silicon joints and voilà... instant custom intake! :grin:

[jmgtp]

I just bought a $7 purolator paper air filter for my 2.5 yesterday... does that count? :razz:

I'd say for a daily driver a paper filter is the way to go. Cheap, excellent filtration, more than adequate air flow and no time/money spent on cleaning kits. If your catching bugs and leaves in your filter now, imagine what winter snow, slush and salt would do to an oil impregnated cotton filter.

[rougeben83]

I just bought a $7 purolator paper air filter for my 2.5 yesterday... does that count? :razz:

I'd say for a daily driver a paper filter is the way to go. Cheap, excellent filtration, more than adequate air flow and no time/money spent on cleaning kits. If your catching bugs and leaves in your filter now, imagine what winter snow, slush and salt would do to an oil impregnated cotton filter.

That's a little extreme; I doubt and bit of salt will actually make it way from the little vent in the grille to the pipe, through the pipe, then into the filter..which will be stay there to begin with.

Big chunks like bugs, leaves, etc. paper or the oil filter will stop them just the same. It's the minute particles from running in a dusty environment where you will see the filtering differences between the two.