Dirt passing through foam {K&N, Holly} filters
02-12-2006, 01:34 PM
#1
Dirt passing through gauze {K&N, Holly} filters I was researching a cold air kit for another car I own, on other automotive sites. I began to notice some posts about how the oiled gauze filters were no longer recommended because they pass too much dirt & accelerate engine wear.
One thread pointed to this test as proof: precise filter test
The conclusion of the test appears to be that while oiled gauze filters DO provide more air flow, they do it with a significant increase in dirt ingested.
Currently, I'm running a Holly PowerShot filter on my WS6, but I'm concerned that I may be allowing too much dirt through to the motor!
What does everyone here think?
One thread pointed to this test as proof: precise filter test
The conclusion of the test appears to be that while oiled gauze filters DO provide more air flow, they do it with a significant increase in dirt ingested.
Currently, I'm running a Holly PowerShot filter on my WS6, but I'm concerned that I may be allowing too much dirt through to the motor!
What does everyone here think?
Last edited by fnbrowning; 02-12-2006 at 02:08 PM.
02-12-2006, 03:05 PM
#4
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I think that's a good study that they did. Now I have proof to show people that aftermarket filters aren't worth it.
I've always used the AC Delco filters because aftermarket filters really doesn't increase power by much at all and they allow some dirt through. Also over oiled filters will ruin the MAF sensor.
I'm glad that there are charts and graphs that prove it.
I've always used the AC Delco filters because aftermarket filters really doesn't increase power by much at all and they allow some dirt through. Also over oiled filters will ruin the MAF sensor.
I'm glad that there are charts and graphs that prove it.
02-12-2006, 03:20 PM
#6
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Originally Posted by fnbrowning
I was researching a cold air kit for another car I own, on other automotive sites. I began to notice some posts about how the oiled gauze filters were no longer recommended because they pass too much dirt & accelerate engine wear.
One thread pointed to this test as proof: precise filter test
The conclusion of the test appears to be that while oiled gauze filters DO provide more air flow, they do it with a significant increase in dirt ingested.
Currently, I'm running a Holly PowerShot filter on my WS6, but I'm concerned that I may be allowing too much dirt through to the motor!
What does everyone here think?
One thread pointed to this test as proof: precise filter test
The conclusion of the test appears to be that while oiled gauze filters DO provide more air flow, they do it with a significant increase in dirt ingested.
Currently, I'm running a Holly PowerShot filter on my WS6, but I'm concerned that I may be allowing too much dirt through to the motor!
What does everyone here think?
OEM Paper filters have been bench flow tested and they are good for upto 500bhp. The only real way to reduce restriction is at the loss of filtering ability.
However many cotton weave and foam filters have been used extensivly. If you have one, don't worry about it.
If you still have a paper one don't waste your money on an aftermarket one.
The best filter type I know of is made by Donaldson, they make the Blackwing CAI for the Corvette. This is sythetic as opposed to cotton weave, it filters almost as well as paper but flows better than most cotton ones. The avaiation industry and commercial diggers heavy plant machinary use them, so they must be good.
02-12-2006, 07:42 PM
#7
Originally Posted by 300bhp/ton
Nothing new here.
OEM Paper filters have been bench flow tested and they are good for upto 500bhp. The only real way to reduce restriction is at the loss of filtering ability.
However many cotton weave and foam filters have been used extensivly. If you have one, don't worry about it.
OEM Paper filters have been bench flow tested and they are good for upto 500bhp. The only real way to reduce restriction is at the loss of filtering ability.
However many cotton weave and foam filters have been used extensivly. If you have one, don't worry about it.
Last week I was driving the other car to work. There is road construction along the street, and some worker was using a concrete saw, creating a huge plume of concrete dust.
My choice is, drive through the dust, or don't get to work on time! Incidents like that, you have to trust your filter will protect the engine. Luckly, the filter in my get-to-work car is AC Delco.
I'm looking at the test, and thinking that i could have been driving through a concrete dust plume with a gauze filter - and the gain isn't worth ingesting more dirt over time.
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02-12-2006, 10:36 PM
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Great link and information.....The only thing is I'm skeptical about the AC Delco filter doing sooooo much better than all the others.
It says that this was a test to see what was the best filter for a GM Duramax diesel. I just find it kinda funny that GM's brand filter did that well on a test for their engine. I dunno, maybe there's nothing to it....or maybe there is. 
If it is legit, though, that sure says a lot for AC Delco filters! If this is how their air filters stack up, what about the oil filters? Anyone seen any data on that?
It says that this was a test to see what was the best filter for a GM Duramax diesel. I just find it kinda funny that GM's brand filter did that well on a test for their engine. I dunno, maybe there's nothing to it....or maybe there is. If it is legit, though, that sure says a lot for AC Delco filters! If this is how their air filters stack up, what about the oil filters? Anyone seen any data on that?
02-12-2006, 10:49 PM
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The AC Delco oil filters do very well. I can't find the old post with a whole crapload of info on filters (theres some website out there...a guy tested about 20 or so filters).
02-13-2006, 03:00 AM
#12
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Originally Posted by fnbrowning
Sorry if this has been discussed before. I did a search and did not turn up anything. One example of why I've started to worry about the cotton weave and foam filters:
Last week I was driving the other car to work. There is road construction along the street, and some worker was using a concrete saw, creating a huge plume of concrete dust.
My choice is, drive through the dust, or don't get to work on time! Incidents like that, you have to trust your filter will protect the engine. Luckly, the filter in my get-to-work car is AC Delco.
I'm looking at the test, and thinking that i could have been driving through a concrete dust plume with a gauze filter - and the gain isn't worth ingesting more dirt over time.
Last week I was driving the other car to work. There is road construction along the street, and some worker was using a concrete saw, creating a huge plume of concrete dust.
My choice is, drive through the dust, or don't get to work on time! Incidents like that, you have to trust your filter will protect the engine. Luckly, the filter in my get-to-work car is AC Delco.
I'm looking at the test, and thinking that i could have been driving through a concrete dust plume with a gauze filter - and the gain isn't worth ingesting more dirt over time.
K&N and other cotton weave filters I personalll feel are a rip off in terms of price and performance. But many many people use them so there is a very good track record.
OEM paper filters will always outperform any other type in terms of filtering. This is due to being paper and nothing else.
02-13-2006, 03:12 AM
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In my personal experience, the cotton K&N-type filters are terrible in flat-panel form, although they work well in the conical style. My K&N let dirt and grit get all the way to my MAF, so I replaced it with a Fram. I've had no problems since, so I'm sticking with the paper filters. However, I use K&Ns in other vehicles and they work great...dunno.
02-13-2006, 03:32 AM
#14
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I think the main problem here is dirt particles getting around the side of the panel filter, this is a common problem with such filter type. If the K&N didn't fit quite as well with as good a sealing edge to them, then that is almost certainly the cause as opposed to the eliment itself.
Many after market setups have major issues such as this. The infamous "Vararam" intake for the Corvette is one such example. The filters where foam and poor quality in themselfs so much so that Vararam had to use an alternative, they also had issues with filter fitment and there have been several high profile cases of recked LS1's due to this (Andy @ A&A Corvette has posted several pictures and info on this in the past).
However I think Vararam have imporved the setup, but it is still a risk.
Many after market setups have major issues such as this. The infamous "Vararam" intake for the Corvette is one such example. The filters where foam and poor quality in themselfs so much so that Vararam had to use an alternative, they also had issues with filter fitment and there have been several high profile cases of recked LS1's due to this (Andy @ A&A Corvette has posted several pictures and info on this in the past).
However I think Vararam have imporved the setup, but it is still a risk.
02-13-2006, 03:39 AM
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I used foam weather-stripping tape and sealed the air-box tight. I think the flat-panel gets overwhelmed (I have a ram-air set-up) versus a cone. You can see where the paper filter get hammered very distinctly...
02-13-2006, 10:13 AM
#18
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except that the cloth probably doesn't filter any better than the air filter. So if the dust passes thru the fitler it will also logically pass thru the cloth also.
Either that or I didn't fully undersatnd your post
Either that or I didn't fully undersatnd your post
02-13-2006, 02:16 PM
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Originally Posted by Silver SS in Germany
AMSOIL has a new air fliter out now. I find it hard to believe that 1 filter was the best in all tests.