K&N filters

[Nix]

Hello All, I am new and would like to say thanks to everyone for such an excellent page. All the info here is overwhelming!

OK here's my question. I installed a K&N FIPK on my truck at approximately 20K. I clean it every 15-20K despite manufacturer recommendations. I always remove the intake tube and inspect it at both ends, and swab it with a paper towel to check for excess dirt.

This time I went about 32K before cleaning. I did notice some grime at the turbo end this time, but very minimal and the inside of the turbo inlet is clean. The filter end (1st 2 or 3") usually has a fine film of oil on it. I have never set any codes, but I have never inspected the MAF.

I have noticed a minor drop in mileage recently, as well as some rough idling,but I attributed it to filter restriction. Is cleaning the MAF preventetive maintenance, or should I leave it alone?

I have noticed that the K&N units are rather unpopular around here.

I'm starting to get the feeling that the K&N should go on Ebay and be replaced with the AFE II.
I love turbo noise :D :D :D ! Is the AFE louder than the K&N?
I have read Kennedy stating emphatically that he would NEVER install a K&N on his vehicle. He obviously knows his stuff, so now I fear that I have been doing damage to my engine. Help!

[rjschoolcraft]

I don't own a Duramax, but I have used a K&N on my 6.5 for over 154,000 miles. Not the first indication of problems from air filtration. Here are some pictures that I just took of the air inlet elbow, that has never been cleaned...

http://www.schoolcraftpowertrain.com/Pictures_&_Data/IM000753.JPG

http://www.schoolcraftpowertrain.com/Pictures_&_Data/IM000754.JPG

Total mileage is 224,094. I'd say the K&N has done a good job of filtering. I have not been "religious" about cleaning it either.

[Nix]

Well, that is quite impressive. I know there are a lot of opinions around here, but it seems hard to argue with your conclusions based on the photos. Have you ever checked/cleaned your MAF? I have also noticed that the wire mesh on the filter will have some oil that seems to fill some of the little squares where the wires intersect(after cleaning and oiling), almost looking like droplets. Should I remove the excess by blotting with a paper towel? Thanks so much for your help! :D

[rjschoolcraft]

Keep in mind that my comments run counter to the consensus on this forum. This subject has been argued repeatedly. You make a wise choice based on the information you have in front of you.

I've seen pictures of inlet elbows off of other trucks that were grimey and loaded with dirt. You can see how clean mine is after a lot of miles. Others have reported good oil analysis numbers with the K&N as well, but that has also been hotly disputed.

My HD Vin F 6.5 doesn't have a MAF sensor.

[LanduytG]

Ronnie
I agree with you and several others except I use a foam filter. As to the use of a K&N or other like filter causing MAF problems IMHO is unfounded as long as the filter is serviced correctly and not over oiled. Oil analysis will show they after market airs do a better job. I am not the only one to see this, JK, George Morrison just to name s couple.

Greg

[rjschoolcraft]

There are some serious problems with those results. One of the things to note is that the testing done there says ther eis no improvement in flow if you leave the filter out all together. This tells me that there is a problem with the test set up or equipment.

On Edit:

For clarification, there was a post prior to this one mentioning a filter test. It has been deleted. My comments are in response to that post.

[ 01-24-2005, 12:02 PM: Message edited by: ronniejoe ]

[yankee]

Uhm ok... (edited image). so there must be something wrong with my truck too since the 1/4mi. and dyno pulls are the same even if i take the filter off? have you ever looked at the inside of the intake using several different filters? if you read the thread i mentioned you'll see many have reported dirt as well as light coming through a k&n if you hold it up to the sky.


Originally posted by ronniejoe:
There are some serious problems with those results. One of the things to note is that the testing done there says ther eis no improvement in flow if you leave the filter out all together. This tells me that there is a problem with the test set up or equipment.

[ 01-27-2005, 07:21 AM: Message edited by: More Power ]

[ADub]

I dyno'd an F150 lightning with and without a filter, made no difference at all

[rjschoolcraft]

I used to pick up about .3 second at the drag strip with my 67 Camaro when I would take the filter off. Maybe that was just in my imagination. I've been known to spin some yarns.

As for pictures, did you look at the pictures I posted in this thread? 150,000+ miles on a K&N without ever cleaning the elbow... This engine was worked hard in some very unforgiving, dirty environments as well as on the highway. Where's all that dirt that they're supposed to let through? Unfortunately, I've had the opportunity to tear my engine down in the last week. The intake tract shows no evidence of poor filtration. In fact, nothing in the hardware yields any such evidence.

From an engineering perspective, and from some one who's worked in the field, there is something wrong with the test that was presented. I've seen other tests that give exactly the opposite results.

In the end, you do what you want. It's your truck. If you want to believe that test go ahead. I can make my own choices and opinions and share them just the same.

[Nix]

Well put, Ron. You can't argue with verifiable proof like your photos. It seems that there are many well-engineered air filters on the market. Like so many other accessories, it is just a matter of what you like. I think empirical evidence like Ron's is the best to go by. If he beats the crap out of his truck for 150K+ miles with a K&N,tears the engine apart and all is well, that's kind of hard to argue with. I have had my K&N intake for 60K+ miles. Pulled out the MAF sensor, clean as a whistle. Good enough for me. Thanks to all for your opinions. :D

[Ted a.]

Originally posted by ronniejoe:
I used to pick up about .3 second at the drag strip with my 67 Camaro when I would take the filter off. Maybe that was just in my imagination. I've been known to spin some yarns.

This is forced induction. You will not see the improvements because the turbo WILL get the air in the engine, providing the exhaust backpressure does not get excessive. We run Grand Nationals at the track into the low 9's and air filtration restriction is not a issue. We have tried no filter and seen no gains with these engines.

[madmatt]

not arguing w/ anyone, you all have get points, but from other R&D engineers I was told that a intake systems greatest restriction was bends in the plumbing if there were any. I'm sure the filter restricts the air some, it has to, but in the case of the Camaro I don't doubt you a bit. I'm sure it's on the carb so therefor it is the only restriction. however under the hood of todays diesels, you'd be hard pressed to have intake plumbing w/ no bends, which would make the bends in my therory, the point of highest resistence to airflow which in turn would make the resistence the filter makes be pretty much a nonfactor. Unless of course it was plugged up. The info I was giving involved a clean filter, on a air hungrey engine w/ stock plumbing.

[rjschoolcraft]

The topic of discussion here was a bench test to the SAE J729 filter test standard. There are no bends to deal with in that test.

The results of the test in question showed that if you removed the filter altogether, the flow was no better than with the stock paper filter...

My Camaro comment was made because of the F150 comment. Yankee's vomit face is rather disgusting and inappropriate. As for turbocharged vehicles, inlet restriction (filters, bends, etc.) will depress the inlet to the compressor making its job require more engergy to achieve the flow rate that you desire.

Hence, my comments.

[Nix]

Thanks to all, except the individual with the vomit face in his reply. I may be new, but I get the impression that this forum is geared towards mature, intelligent conversations and exchanges of ideas.
I guess I'll stick with the K&N. Anyone know of aftermarket turbos for the LB7 yet? I won't be happy until my turbo whistles louder than the big rigs! :D :D :D

[Kennedy]

I've had very poor results with gauze type filters. The foam filters produce the best results for me over and over again. AFE has introduced their Pro Guard 7 media as they too found the standard gauze to be ineffective at stopping dirt on turbocharged engines.

FWIW, Honda ATV's which are generally revered for longevity, and quality typicllay use foam filters produced by Uni. It's not because they are cheap...

[madmatt]

i perfer foam as well. also the bulletin you have all been waiting for is out... GM states that your warr will NOT be voided for running a aftermarket, however...... if the failure is a MAF sensor contaminated from an excessivly oiled filter that and any resulting damage( there example was trannys) is not repairable under warr. My sugguestions is to keep a stocker an a can of brake cleaner handy @ all times and keep a good relationship w/ your local dealer. It is ultamitly up to them to warr. it or not. i'm not saying that just cause i work for a dealer but a good aditude and relationship w/ your dealership does go a long way. their more likely to look the otherway in situations like this and they have the power to cover out of warr. repairs under goodwill. trust me , it's much easier to brush off a total pain in the a55 then a super nice customer.