Air filter testing

[hookedup50]

I have been reading the thread where WW has been doing dyno tests on the turbo choices we have and there is mention of an air filter being a clear winner. So has anyone done real world testing on air filters. Lab tests(on filters) don't hold much water with me as the company doing them is usually selling the product. My truck came with the k47 box and had a KN filter in there, but does does that filter allow more air flow at the expense of filtering particulate? Thanks in advance for input

 

[THEFERMANATOR]

The K&N filters actually don't flow as well as a stock one does after a very short time. Theres a link somewhere to an independant test, and it showed that when freshly serviced the K&N outflowed the others, but after a small amount of particulates built up on teh K&N it flowed less than a regular stock paper filter. Not to mention that the K&N doesn't filter well until it gets some dirt built up on it for the oil to mix with. There are better filters out there than stock, but K&N isn't one of them.

 

[hookedup50]

Thank you and I have read that about kn filters and have also been told I have a clogged filter from oil testsing on one of my gassers. I do like cleanable filters though.

 

[THEFERMANATOR]

AFE makes some good cleaneable filters that aren't oiled. I'm running one on my SUBURBAN.

 

[WarWagon]

I did not do any testing of air filters. My comment was that the HP/TQ spread between the two turbo's was so small it would be bragging rights for a crappy air filter company like K&N to use in marketing. This was just an example of how close the dyno numbers were on the turbo's not an air filter test.

The High cap paper K47 air filter doesn't fit in the K47 box very well - almost too large. Box had trouble closing and keeping sealed to the fender. Gaps at the box halves with the larger paper filter in it.
I used the AMSOIL nanofiber air filter with the HX40II because the stock paper and intake tube would not work on the 4" turbo intake. It is a dry and cleanable air filter and I liked how well it worked.

The K&N filter is a gravel screen. Look in the intake tubes at the white dirt build up the K&N is letting by. Sanding your rings down... Screwing up IAC's on gas engines and made me walk once due to an IAC failure from dirt. So other than deservedly hating the garbage K&N product...

 

[hookedup50]

Thanks, I guess I misread. I just want to get rid of the Kn filter and not repeat the problem I already have. Great turbo thread by the way, and don't like the idea of sandblasting my ATT. I've only had the truck running well on the repower for a week now so haven't had to worry about what air filter it has. Thanks again.

 

[Will L.]

I have a k&n but different shape and housing. After loosing a cam bearing at about 53,000 miles on an optimser I asked the same thing a few weeks back. "unit453" responded and was involved in testing back in 2003. Search and it will pop up. I chased it being 10 year old info and found across the board that the cleanest filtering, slowest to 'plug up', lowest particulate penetration air filter not just for our engines but almost every test done by TRUE independent research was AC Delco. I spent probably 45 hours researching all I could.

The others out there are good, but you cant use brand x testing to see how good brand x is. You have to compile multiple tests to see the similarities in numbers to get the whole picture. If I pay your wages or give you free stuff to evaluate my gear do you give a bad report? Do you want a chance at more free stuff from that or other vendors?

I will still run my k&n but i have learned to oil it heavier than i thought i was supposed to, and to clean it more often. In talking to the head engineer at k&n he said everyone who "experience the myth" that it filters a little better when slightly dirty is running it to dry. He said the #2 mistake involved is buying the 1 gallon soak oil jug and trying to spray it on, it is supposed to be dipped in that oil. I was guilty on both accounts.

My under oiled K&N had higher silicone showing in the engine oil, but I had no tracking in the bearings or cylinder walls. I called in a couple favors from an oil engineer and metalurgist specializing in erosion. (thought somebody might be buying me a new engine). Turns out the GM design and built (when they stopped using Melling) rolled cam bearing crimped connection was the culprit. Both the guys said the air filtration was doing an ok job not great but ok.

K&N is a good way to save money in not replacing the Delco frequently. Understand I dont say that lightly because I have spent many a year cursing AC Delco.

I hesitated to post this do to difference of opinion. My experience and my research only. I say do your own to determine what adds up to you.

 

[6.5L]

My AFe does an amazing job of filtering. It is a oiled filter. But it does seem to need cleaned fairly often. Filters amazing, just plugs up after about a month. That does include some dirt road driving though.

 

[1999gmc]

Here's my experience with K&N. When I first bought my truck I bought a K&N for it. Then I decided to install my intercooler. So when I pulled the duct off the turbo to re-clock it for the intercooler tubing I noticed I had gritty type oil at inlet. I called K&N and told them what I found, and the guy told me to put some sort of grease on the inside of the filter inlet then tighten the clamp. He said the GM plastic housing is not a perfect sealing surface and if I do this and still have dirt getting there, give him a call. So I did as he said and all has been fine for 55K miles. Never saw signs of dirt there again. My Dad has had a K&N on his powerstroke for 175K miles, with no problems at all. Another buddy bought a powerstroke with 150K on it. Put a K&N on, and within 10K miles the turbo took a crap. Could it have been the K&N, or was the turbo on its way out from neglect of the previous owner?

 

[Husker6.5]

I'm running an Iceman oiled gauze filter for nearly two years in the K-47 on my '98 Burb. I'm impressed with it's filtering performance so far. I'm running year round without the lid on the K-47 for better breathing and cold air induction. Had a leak at the downpipe-turbo outlet joint for about 9 months (alignment issue) that blew a lot of soot out and all over the back and bottom of the turbo where it couldn't really be seen. However; under hard acceleration, that soot was sucked onto the outside of the filter where it was stuck in an approx. 1/16" layer all over the filter. After correcting the exhaust alignment issue, I removed the filter element and inspected it. There was no evidence of soot on the inside of the filter media nor in the turbo intake tract. I just gently tapped the filter on a hard surface to knock the loose soot off, used low-pressure regulated air (10psi) and a blow gun to gently blow the remaining soot off the filter from the inside out, and reinstalled it without cleaning and reoiling it about nine months ago.

Oiled filter media is a highly efficient filtering agent. The differentiation between them is the number of layers of gauze material used. I personally wouldn't use one with less than four layers of media. Some brands use five, seven and eight layers of media.

The newer dry media filters I don't have any experience with, yet. I bought a couple of those AEM dry media filters off of eBay cheap (like about $10 each plus $15 shipping) (the link was in another thread about a year ago that was discussing air filters, I think part of Raceday's HX40II install thread) that have a 4" outlet and fit in the K-47 airbox. They'll need an adapter to neck them down to the turbo inlet diameter, I'm going to see how the stack up against an oiled media filter.

 

[Will L.]

keep in mind monitoring. Exhaust sampling is the most accurate way of knowing, but to expensive to do. Oil sampling is the next answer and will usually pay for itself in extending time between oil changes. If you aren't doing 1 of these how do you really know how it is doing.

 

[Husker6.5]

My "evidence" is visual: No crap in the intake tract post CDR. With all that soot covering the element, there wasn't any in the oil film from the CDR inside the intake tract.

 

[WarWagon]

I will still run my k&n but i have learned to oil it heavier than i thought i was supposed to, and to clean it more often. In talking to the head engineer at k&n he said everyone who "experience the myth" that it filters a little better when slightly dirty is running it to dry. He said the #2 mistake involved is buying the 1 gallon soak oil jug and trying to spray it on, it is supposed to be dipped in that oil. I was guilty on both accounts.

K&N sells a spray bottle and a spray can to oil the filter. So I say the engineer is a :liar:
Add too much oil and the MAF WILL get oil fouled.

I ran a K&N on a 2002 5.3L V8. One day it would start and immediately stall out. Revving the engine would keep it running, but, return to idle it stalled. Few times of this it ran again. Later it quit again and I could not shift with the engine running. I walked. Later I noticed the idle speed was like 400 RPM. Pulling the intake down found a fine white dirt layer in the intake. The IAC had this dirt built up on it except where it did a touch to learn IAC position.

In effect the IAC was a fingernail thicker and more restrictive then it was at the factory. The dirt wore off the touch area giving the computer no way to correct for the increased thickness of the IAC. This caused the engine to stall from lack of air. The dirt the K&N let by had built up so much on the IAC that it would not stay running.

The other application I used K&N on was a jet boat. I should have stuck with just a flame arrester because my carb would have stayed cleaner! The oil would not stay on top of the air filter and would leak off at the bottom of the filter. So I had a white top and extremely wet bottom of the filter. See pics of the oil and dirt in the intake and carb the K&N cheerfully let by.

Wipe a paper towel in the clean side...



Oil that ran out of the now white filter.



Pic of the white filter from sitting less than 30 days.




Those with a DPF should run the best air filter possible because the DPF will clog up with unfiltered dirt that can't be burned out. What does a $1000 part replacement from running a K&N filter do for you?

Most dirt goes out the exhaust. The dirt that shows up in the oil has scratched the rings on the way down. :nonod:

 

[Mike K3500]

I think that if any type of gauze / oiled filter is it used, it probably should have an "outer ware" on it.. but that just really adds to the price of an "already" expensive filter...
I have the S&B oil gauze filter on my truck now, but will be replaced when it's road ready, as well as the K&N on my Impala

 

[jrsavoie]

From what I remember the Baldwin filters were right there with AC Delco's

I have a k&n but different shape and housing. After loosing a cam bearing at about 53,000 miles on an optimser I asked the same thing a few weeks back. "unit453" responded and was involved in testing back in 2003. Search and it will pop up. I chased it being 10 year old info and found across the board that the cleanest filtering, slowest to 'plug up', lowest particulate penetration air filter not just for our engines but almost every test done by TRUE independent research was AC Delco. I spent probably 45 hours researching all I could.

The others out there are good, but you cant use brand x testing to see how good brand x is. You have to compile multiple tests to see the similarities in numbers to get the whole picture. If I pay your wages or give you free stuff to evaluate my gear do you give a bad report? Do you want a chance at more free stuff from that or other vendors?

I will still run my k&n but i have learned to oil it heavier than i thought i was supposed to, and to clean it more often. In talking to the head engineer at k&n he said everyone who "experience the myth" that it filters a little better when slightly dirty is running it to dry. He said the #2 mistake involved is buying the 1 gallon soak oil jug and trying to spray it on, it is supposed to be dipped in that oil. I was guilty on both accounts.

My under oiled K&N had higher silicone showing in the engine oil, but I had no tracking in the bearings or cylinder walls. I called in a couple favors from an oil engineer and metalurgist specializing in erosion. (thought somebody might be buying me a new engine). Turns out the GM design and built (when they stopped using Melling) rolled cam bearing crimped connection was the culprit. Both the guys said the air filtration was doing an ok job not great but ok.

K&N is a good way to save money in not replacing the Delco frequently. Understand I dont say that lightly because I have spent many a year cursing AC Delco.

I hesitated to post this do to difference of opinion. My experience and my research only. I say do your own to determine what adds up to you.

 

[jrsavoie]

If you are running with the lid off of the K47, you are sucking hot engine compartment air. Or I misunderstood your post

I'm running an Iceman oiled gauze filter for nearly two years in the K-47 on my '98 Burb. I'm impressed with it's filtering performance so far. I'm running year round without the lid on the K-47 for better breathing and cold air induction. Had a leak at the downpipe-turbo outlet joint for about 9 months (alignment issue) that blew a lot of soot out and all over the back and bottom of the turbo where it couldn't really be seen. However; under hard acceleration, that soot was sucked onto the outside of the filter where it was stuck in an approx. 1/16" layer all over the filter. After correcting the exhaust alignment issue, I removed the filter element and inspected it. There was no evidence of soot on the inside of the filter media nor in the turbo intake tract. I just gently tapped the filter on a hard surface to knock the loose soot off, used low-pressure regulated air (10psi) and a blow gun to gently blow the remaining soot off the filter from the inside out, and reinstalled it without cleaning and reoiling it about nine months ago.

Oiled filter media is a highly efficient filtering agent. The differentiation between them is the number of layers of gauze material used. I personally wouldn't use one with less than four layers of media. Some brands use five, seven and eight layers of media.

The newer dry media filters I don't have any experience with, yet. I bought a couple of those AEM dry media filters off of eBay cheap (like about $10 each plus $15 shipping) (the link was in another thread about a year ago that was discussing air filters, I think part of Raceday's HX40II install thread) that have a 4" outlet and fit in the K-47 airbox. They'll need an adapter to neck them down to the turbo inlet diameter, I'm going to see how the stack up against an oiled media filter.

 

[Husker6.5]

No, you read right. I'm running with the lid off for two reasons:

1. The '98 Burb has that damn plastic snorkel that runs from the air box through the inner fender to under the passenger headlight behind the turn signal, so it doesn't breathe that well through a 3" x 2" inlet and all those bends and constrictions. Seat of the pants dyno says it's definitely breathing better with the lid off. The sound of the turbo spooling up is pretty sweet, too. I also gained about 1.5-2 mpg highway, most likely as a result of the combination of the oiled gauze filter and removing the lid so it could breathe better.

2. With the exception of sitting at idle, the under hood air temperature is not that much higher than ambient air temperature when the Burb is at speed when highway cruising. I've pulled the cowl to hood rubber gasket off, and that gives me an approximately 1/2" (1.25cm) gap to let air from the engine compartment flow out. Poor man's cowl induction hood, if you will (one benefit I've noticed the past two winters is that my wiper blades and the lower few inches of the windshield are now much less prone to icing up, must be the warm air escaping through the gap and flowing across the filler panel and up the base of the windshield). I placed one of those adhesive max. temp recording thermal strips on the inside of the topless K-47 adjacent to the turbo to see how much hotter the under hood temp was while driving compared to the ambient temperature. On a day it was 0*F out, temp inside the open K-47 was 8*F. 62*F amb., K-47 temp was 100*F. The day I came back from Denver last summer I got ambient readings of 113*F (USWS confirmed) on I-76 by Sterling and Ft. Morgan CO. Max registered K-47 temp was 165*F. I waited until I pulled over in Julesburg and quickly popped the hood with the motor running and pulled the thermal strip to try and avoid heat-soak from falsely bumping up the recorded max. temp.

For the slight increase in intake air temp running lidless, IMHO the trade off in better breathing of slightly warmer air, especially under load, vs. breathing through that snorkel is worth it. Especially until I do Raceday's battery/K-47 position swap and rotation, and fabricate a much better flowing ram air scoop drawing either from just below the front air dam or the passenger side bumper inlet. Yes, I suppose I could do a snorkelectomy and cut a hole through the inner fender to draw from the wheel well, but this is so much easier, just take the lid off and leave it on a shelf in the garage.

 

[NVW]

The snorkel can be removed.

 

[Husker6.5]

I know. Read the last line of the last paragraph.

 

[Will L.]

Sorry for not explaining well about the k&n oil. There are 2 viscosities of their oil. 1 is in manual spray bottle, aerospray bottle, and in a jug marked for use in a spray bottle. They also sell,or at least sold, (i bought a couple gallons) a different viscosity that is supposed to be poured into a clean container, dip the filter in, let dry, and pour the balance of the new oil back into the container.
I am going to run mine with close oil sampling. First sign of high silicone its in the trash. Buying it was a mistake. I should have run the Delco all along.
Baldwin did good but not as much flow, and still plugged quicker. Take % of quicker fill and divide that # into the price difference. That will tell you which is cheaper to run.
Sample oil to save a engine before major problems. It will pay for itself by loger run time on oil,oil filter, air filter. No disrespect but you cant see the fine sands going thru the filter. A perfectly clean filter in the front seat isnt plugged. It also isnt stoping dirt from the engine.
Too much air filter oil going into the engine wont hurt it, think cdr, blowby, etc. UNLESS as in WW's case you plug a sensor. For this truck no maf/map so I am ok. I recomend against using this filter in most vehicles.