Keep K&N or NOT ?

[ARCOgraphite]

As I mentioned on here before, my Factory air fiter on my Nissan was over-oiled and it messed up my MAF. That Factory filter was SO oily that the box I tossed it in ( the replacement STP Air filter cardboard box ) was completely saturated with oil in a month. And it was NOT engine oil. The oil had no odor - its was like a USP grade mineral oil. I had to buy a can of MAF sensor cleaner and spray the MAF.
After about a few day the engine seemed to run better - Ken

p.s: Also note, there are low and high efficiency air filters available in the aftermarket. I did note that the High efficiency really killed WOT power at peak rpms. Something to think about.

 

[MRC01]

... A filter cleaning kit should last the life of the car and is about $15. So add that to your filter price compared to throw-aways. On my vehicles with drop-in K&Ns, it's a 50K cleaning cycle so the kit will last "forever". UOA data doesn't support that these are "contaminating" my sump on the cars I have that I run them on/do UOAs. ...

Same experience here. I've run K&N air filters in cars & motorcycles and UOA results did not show any difference compared to a paper filter. And in the long run cleaning and reusing them is cheaper than replacing and saves you a trip to the store. If you get a HP/efficiency bonus that is too small to feel and barely enough to measure, fine.

 

[Trav]

Maybe Fauci can use it as a third mask with some goggles, if not toss it in the trash.

 

[Silver]

After seeing a throttle body coated with a thin film of dust, never again.

 

[skrypj]

After seeing a throttle body coated with a thin film of dust, never again.

Same happened with my 1995 4Runner. I don't know if it as poor fitment of the K&N or simply the filter letting stuff through, but the entire intake was full of dust. I switched it back to a paper filter and no issue.

 

[TiGeo]

Same happened with my 1995 4Runner. I don't know if it as poor fitment of the K&N or simply the filter letting stuff through, but the entire intake was full of dust. I switched it back to a paper filter and no issue.

Of all the cars I've run these in, spotless intake tracts. It's got to be poor fit or v. dusty conditions.

 

[kschachn]

Of all the cars I've run these in, spotless intake tracts. It's got to be poor fit or v. dusty conditions.

If it's due to dusty conditions, wouldn't that mean the filter isn't filtering properly?

 

[nomas]

K&N equals better air flow because the pores in the paper are larger . This is why you have to oil it to hopefully trap what might otherwise get through . Nothing magical about it .

 

[Trav]

What paper?

 

[y_p_w]

What paper?

Yeah - everything is different in OEM or even aftermarket filters. For the OP's application, I believe Subaru uses OEM oiled paper. I've seen some filters that are dry depth type - especially Honda. I still have a Subaru, and I've seen aftermarket equivalents that are are dry paper/fiber.

As for K&N and the type, I've heard of a few oiled gauze filters in factory applications. Saw a Toyota 86 TRD at a dealer and looked under the hood. It had a sticker on the air box saying that it used a reusable filter that would need to be periodically re-oiled.

 

[adams355]

A lot of high end performance/track turbo cars are not even running air filters these days, so I reckon my K&N is doing a much better job than that. Some run the mesh or nothing at all at the drags. I still haven't heard a disaster story yet

 

[Trav]

Velocity stacks were also popular at one time, engines operating under racing conditions are not expected to have a long lifespan, wear from not running a filter is the least of their problems.

 

[RooflessVW]

A lot of high end performance/track turbo cars are not even running air filters these days, so I reckon my K&N is doing a much better job than that. Some run the mesh or nothing at all at the drags. I still haven't heard a disaster story yet

Not a great example. The car/engine/turbo may last years but the engine only runs for tens of hours.

A daily driver will put on thousands of hours.

 

[adams355]

Velocity stacks were also popular at one time, engines operating under racing conditions are not expected to have a long lifespan, wear from not running a filter is the least of their problems.

I'm not talking about 'race cars' I am talking about heavily modified street cars at the drags and/or on the street. Its been popular for over 10 years now not running a full filter on the turbo. Some cars even have the turbo's out the front of the bonnet getting ram air as well.

 

[RooflessVW]

I'm not talking about 'race cars' I am talking about heavily modified street cars at the drags and/or on the street. Its been popular for over 10 years now not running a full filter on the turbo. Some cars even have the turbo's out the front of the bonnet getting ram air as well.

I promise you that the compressor wheel lifetime is impressively short on such cars.

 

[Trav]

I'm not talking about 'race cars' I am talking about heavily modified street cars at the drags and/or on the street. Its been popular for over 10 years now not running a full filter on the turbo. Some cars even have the turbo's out the front of the bonnet getting ram air as well.

View attachment 59468

Turbo engines especially need good air filtration for long turbo life, all engines benefit from high efficiency air filtration. Hey if you want to run no filter or some crap filter its you engine and your money have at it.

 

[adams355]

Turbo engines especially need good air filtration for long turbo life, all engines benefit from high efficiency air filtration. Hey if you want to run no filter or some crap filter its you engine and your money have at it.

Its a huge thing there are literally 100000's of people doing it. I wouldn't do it but I haven't heard of any real disasters from doing it either and I know a lot of people involved in tuning etc

 

[RooflessVW]

Its a huge thing there are literally 100000's of people doing it. I wouldn't do it but I haven't heard of any real disasters from doing it either and I know a lot of people involved in tuning etc

Well excuse us if we don't side with your anecdotal "evidence."

Show me a white paper that says filtration doesn't matter and I'll come around.

K&N? Fine. No filter? No way.

 

[adams355]

Well excuse us if we don't side with your anecdotal "evidence."

Show me a white paper that says filtration doesn't matter and I'll come around.

K&N? Fine. No filter? No way.

Can't you read it says I wouldn't do it... Did you forget your glasses

 

[RooflessVW]

Can't you read it says I wouldn't do it... Did you forget your glasses

So you wouldn't do it, but it's fine.