I use my truck for travel, very little around town and no off-road. Last summer I was in Washington State visiting my brother and his little town didn't have a NAPA dealer so I replaced my dirty NAPA Gold air filter with a K&N, the only one in town which fit.

I just got my most recent oil analysis back and darn if my silicon PPM isn't ten times greater than the last analysis. The last analysis was with the NAPA Gold filter I took out. But it gets worse: the K&N air filter was used for only 1/3 of the oil drain cycle, so in rough figures it passes 30 times more dirt than the NAPA Gold filter.

Yes, I greased the gasket real good with their silicon.

My previous oil analysis was 4 PPM silicon for 6000 miles.
Current oil analysis is 41 PPM silicon for 6000 miles, only 2000 of that with the K&N filter. I attribute all of the extra silicon to the K&N filter.

I had no change in power produced after I replaced the dirty NAPA Gold with the high flow K&N, so apparently the NAPA was still OK, and it wasn't very old. My filter minder has never moved off of zero.

Needless to say, I installed a new NAPA filter today. K&N on the junk pile. BTW, my new NAPA has a new feature: a foam cover 1/2" thick over the paper pleats. This should keep the pleats from loading up with dirt, and when the foam loads up I can just rip it off and run with paper only for a while.

I make these conclusions: The K&N passes a lot of dirt. The NAPA passes enough air for the engine (about 250 HP ?), even when dirty, and traps the dirt. At my HP level I don't need a "high flow" air filter.

 

I wouldnt so much as put a K&N sticker on my truck, let alone the crappy filter...junk, IMHO.

 

I dont like a filter i can see through. Had one that the owner had put on it. Stopped by napa on the way home from buying the truck for a BHAF.

 

Great for race motors that get frequent oil changes and regular rebuilds, not for our trucks.

 

Agreed. If flow is super-important to you, then just take off the filter entirely. This will give you even better flow than the K&N, while keeping the filtrations at the level of the K&N.

BHAF isn't much of a flow improvement over stock (maybe 30%), but it DOES flow more while still maintaining filtration.

IMHO, the UNI oiled foam and the AFE PG-7 don't filter quite as well as the BHAF, but still filter good enough to not be a problem, and they flow SUBSTANTIALLY more.

Compromises, compromises.

Justin

 

****!!! after reading this I wonder why did I install a K&N air filter??? and they are not cheap. What should I do?? What kind of filter should I use??

 

A rough air filter calculation yields a flow of around 1850 CFM with the BHAF and the stock brick filter is around 450 CFM. Thats more like a 400% increase in flow...

I could suck the filter minder down on the stock box to the replace line, with the BHAF I am sure its not even close, not to mention you get rid of that large gasket area to seal and have a clamped filter connection.

J-eh

 

I would say that you did not get a good seal. I have never had a problem with running a K&N. I get 4 to 6 ppm for silicon on all of my oil analysis. Maybe your paper filter was real bad, that can happen too.

 

For every person who says they are junk there are many who say they are just fine. I've had a K&N drop in in for 224k and have never had an oil analysis come back with more than 6ppm silicon.

The main reason people have trouble is because they over service them or peek in the airbox all the time thinking they can see when the filter is clogged. Totally counter-productive waste of time, a dirty looking filter can be fine and a clean looking one plugged. Also every time you pop the airbox open you risk losing the seal around the outer edge which should have silicone grease applied to one surface. If I was going to run a stock filter I'd grease it also.

As with any filter the dirtier the K&N is the better they filter, keeping them clean looking is worthless.
I service mine every 100k or when the filter minder says it's time.
If you want to see if the filter is passing dirt remove the inlet hose from the turbo and wipe the inside with a white rag at every oil change. My hose has been spotless for almost ten years now, the K&N has only been cleaned and reoiled twice. I live on a long dirt road in a dusty agricultural area.

 

I would have to agree with Holsteinman and Infidel. I have been running a K&N filter for several years now and the last time I had my oil analyzed I had 12500 miles on it and my silicone level was 5PPM.

 

Sealing the filter with silicone and oil samples I musta missed that class over the last few years. I run a k&n incognitio .

Hint- sig.

 

Can I ask where you got the flow numbers for the BHAF? Mine dropped 150 degrees, but doesn't seem to be a drastic improvement over stock.

Justin

 

I have a K&N model # RE-0880. It was $50 cheaper than any AFE cone filter i could find(which is what i would have rather had), and i have wiped out my intake tube a few times since ive had it in. I have never had ANY dirt/residue come out of the intake tube/turbo blades. I think everyone makes a big deal out of something thats not. What is even bad about a high PPM level? What does that mean, and what will it harm? Im not saying i want a high PPM level if lower is better, but i just dont see why everyone hates K&N. An AFE that is the same size or maybe a little shorter flows about the same, and IMO the greater the flow, the less filtration you will probably have. The more surface area of the filter, the better, but the K&N has as much as an AFE, and they are made of the same material. Why is the AFE so much better? Like i said. I would rather have an AFE, but they are $50 more than what i paid for my K&N, and a BHAF needs to be replaced every so often,and wont flow as good. I just dont think they are THAT bad of a filter myself. BTW. I dont do oil Analysis tests, but would like to do one sometime. If i ever do ill let everyone know how it goes.

Eric

 

I just used a filter flow calculator I got from a Dodge Performance page on the DTW.. It had a spread sheet where you put in the diameter of the filter at either end and the length. Its a really rough calculation from what the formula shows, but its closer than what I had before.



150° isn't drastic enough? Heck you could spend $1200 on an exhaust system and only get 50°.. 150° is drastic IMHO... Thats alot more air.

 

I dont do oil samples but I just put a head gasket on my first gen and could still see the hone marks in the cylinder walls at 120k. Thats good enough of a sample for me. Clean and oil properly.