General Category >> Technical Documents/Reference >> Inexpensive high performance air filter

Message started by Oldfeller2 on 07/05/07 at 06:05:44

Title: Inexpensive high performance air filter
Post by Oldfeller2 on 07/05/07 at 06:05:44

This idea is not new, BTW -- Paladin and others have done this trick using very similar media many times in the past.

This is an excerpt from the Cafe thread "Lessons from Master Yoda" and expansions and discussions can be read here.;action=display;num=1183598846


So I wanted to get me a high performance muffler and a high performance air filter to go on my Savage.  I wanted the higher performance level out of my scoot, I just didn't want to pay a lot for my muffler.

So I went to the smelly old swamp to talk to the Master of Cheapness himself.

Yup, I asked that cheap old hand puppet Master Yoda to be a'teaching me some of them old-timey Jedi ways of his.


"He who is the most tight has the might to fight" -- always remember this, young paduwan" he says to me.   Then he gives me $20 bucks and tells me to go do it.  Didn't tell me how, just told to me to "go do it".


So, I went and picked me up a take-off Harley muffler from a local chop shop with a junkyard of take-offs out behind it.  $10 for the muffler (very clean looking piece of chrome, too).   Got all the mounting brackets and clamps with it to boot.  So far, so good.

Problem is I've eaten up over half my budget already ($20 is all cheapskate ol' Yoda gave me to do the whole high performance project with) and I still needed to get me a high performance low resistance air filter to uncork my air system.

Researching the internet tells me air filters cost money.  K&N gets $40 bucks out of you either way you go.  The competitors can shave you $10 off K&N's prices -- but it is still way too pricey to suit ol' Master Yoda and his $20 budget.


I try to tell this to Master Yoda that and he takes my light saber away from me for paying too much for the muffler.  Shucks.  Then he makes me stare at the OEM air filter for 20 minutes and meditate on the ways it fits in with the flow of the force.

Then he slaps me upside the head bone, tells me to THINK with this hard lump of bone I've got sitting up on my shoulders and then he sends me out to the Home Depot and the Lowes with the OEM filter in my hand.  He won't tell me why he's sending me there, either.

He just makes two flashing cuts at the stock Suzuki air filter and severs the fabric away from the sheet metal frame (just missing the wire mesh on the outside surface and only nicking my fingers just a little bit -- he's a mean old sod but he's pretty durn good with that dinky little lightsaber of his when he takes a mind to swing it some)  

He makes me study the screen and the empty frame a bit more, then he says to me


There is no "try" == Do, or do not do.   Live, or you can die "trying" like the young fool that you truly are.



Title: Inexpensive high performance air filter
Post by Oldfeller2 on 07/05/07 at 06:14:04

I get in the car and go to both megastores and I look high and low for something to put into that steel frame to turn it into a high performance low resistance air filter.  I look in the house air filter stuff.  I look in the lawnmower parts stuff.  I look in the pool filter stuff.  I look in the humidifier stuff.   I look everywhere, but nothing will make that steel frame into a high performance low air resistance cleanable air filter.  

Ol Yoda's really gonna kick my butt -- and the people at these stores are all idiots even when you can find one to ask them a question.  Heck, they even send me off to the window air conditioner area to look at the flimsy little air filters that go on those pitiful things.  Useless -- it's nothing but a see through it skinny-thin piece of polyester cloth anyway.


On the way back to the swamp to get my butt kicked, I cast my eyes over along the strip malls and I notice that the Hobby Lobby is open on the 4th of July
(strange, I didn't know them old knit-witches were open on holidays)

I stop and go in -- I mean, what have I got to lose?   I'm in such a big hurry to get back to the swamp and get my butt kicked?

I go up and show the empty frame and screen to the knit-witch on duty and she smiles a toothless smile at me and says

"Come with me, sweetie....  hee hee __ we'll fix that ol Yoda for you"

and she grabs up her cane and hobbles off into the tall stacks of crap that are everywhere in that store.   We go past the fake flowers and past the wreaths.  We trudge past the nicknacks.  We go all the way back to the quilting section and I know the old bat is really off her rocker when she tells me to pull down this big square chunk of white crap from off the top shelf.

"Dearie, you just got to understand a few things about how things really work.  K&N started out as a thin layer of cotton batting trapped between two pieces of screening with a little canola oil sprayed on it with a few drops of red food dye in the canola oil to make it look all "expensive" so the suckers would buy it.   That's all it was originally, simple thin cotton cloth.  If you didn't oil it, it would rot out on you after a few years.  Modern spun bound polyester fabric is more durable and much better rot-wise, so we'll use that for our filter element.

Now what you do is take this nice 1" thick inter-linked fine spun polyester batting and cut it into a nice 5 1/2" square then you just tuck it into that steel frame you got in your hand and then you spray a little canola oil on it (Pam will work just fine if that's all you've got, dearie) after you get it tucked in place good.  And sweetie, remember to leave off that outside door from your air box and to rip out that ugly rubber snorkel thingy too so your engine can breathe all better for you.  


Title: Re: Inexpensive high performance air filter
Post by Oldfeller2 on 07/05/07 at 06:16:51

Now when service time comes, dearie, just pull the batting out of the frame and wash it in the kitchen sink with some dishwashing soap and rinse it out real good with some warm water.  Lay it out flat and let it dry flat, then put it back in the frame and spray some more canola oil on it to collect the tiny fine bits of dust and pollen that are in the air.

You got enough material there to make yourself four replacement filter elements, so you just rotate them on through one at a time so they have months & months of time to dry out good after you wash them.

And mind you dearie, you remember to tell that old skinflint Yoda that Marcie still remembers that night when he left me at the restaurant stuck with the check because he had to go fight an evil Sith Lord (or so he said, anyway)."

"How much is this stuff, anyway?"  sez I, not wanting to buy any of this expensive looking soft luxurious 1" thick air light tightly woven cloth-like material.  I mean, Yoda's really gonna kick my butt anyway for even talking to this old witch in the first place, much less for spending even more of his money.

"It's expensive dearie, the good stuff always is.  

$3.14 plus tax."

I got back to the shop and got out the big scissors.  The material cut easily and sprang back to being 1" thick instantly.  It seems resilient.  I tried breathing through it and I got no sensation of resistance at all.  I took a piece of the old OEM material and it had tons more resistance than the 1" thick bat material did.   Heck, if it were all oiled up like a K&N it would trap and hold all sorts of dirt.

I put it into the rim lipped steel framework and the new filter element material compressed slightly and gripped the frame and held tight, just like the old witch said it would do.  I sprayed it down with some canola oil and put my scoot all back together (yanking the snorkel and leaving off the air door just like Granny said) and she cranked up and ran just fine.  Got me some serious intake air noise now, you can really hear the old girl moan lustily when you twist her tit now.

Got an minor new issue on cranking her down hard when coming around the end of a hard leaning turn -- she likes to slip the rear tire over a bit now when the hammer drops when she wouldn't do that in the past at all.  Got to be bit lighter in the wrist when coming out of them hard turns now or I may get into trouble.

My pipe is getting a tiny mite bluer looking -- may have to adjust things some soon.

Master Yoda?   Naw, he wasn't impressed any a'tall when he saw my high performance low air resistance $3.14 air filter rig -- he just asked me for his change back from his $20, tossed me my lightsaber, called me a smart arsed young wippersnapper and told me to get out.


I guess he remembered old Marcie after all ....


Title: Inexpensive high performance air filter
Post by Oldfeller2 on 07/05/07 at 06:26:57

Poly-fil Nu-Foam is what the stuff is called.  It is a newly developed fine spun fiber thickly populated polyester batting that is really thick, up to 4" thick, that is intended to replace expanded cell foam in places you don't want mildew and rot to take place.  Plus, it can't smother your newborn baby with his bedding because he can breathe right through it
(real popular stuff with the mommie types on the baby isle).

This stuff is available at anyplace that sells women's hobby supplies for obvious reasons.  If not, type nu-foam into your browser and the net will sell it to you.

If you have any issues getting the batting to stay in your frame (you didn't cut it big enough for example) you can recover by using a needle and thread to lightly go through the batting, through the screening and back up again.  Big loose stitches are what is needed.  Don't pull anything tight as that will screw up your loft (height) which is important to your filter's ability to pass lots of air.

I spray my nu-foam with Mazola PURE canola oil (little yellow spray can) because it is thick and clingy and it does not have flour or other solids in it.  I also use the stuff to lube my shredder cross-cut head by spraying it on a piece of paper then shredding the paper.

As far as the Star Wars story line goes, it makes it more fun to read -- techie how to do it stuff can get deadly boring to read otherwise.  Ain't much fun to write, either.

And if you think the story was funny, you shoulda seen the looks I got from the real knit-witches at the artsy-craftsy store for picking up various pieces of their stuff and breathing and blowing noisily through them .... they musta thought I had me a stopped up nose or something.


Warning:  For you modern bike style guys with catalytic converters and computer driven oxygen sensors on your scoots -- oil sprayed on air filters can kill several hundred dollars worth of your sensors.  It's the oil that gets in the air stream that does the evil deed to your very sensitive sensor heads.  Our Savages don't have any of such like techie stuff, being understandable type carburetor-based old style scoots.  



Title: Sewing is necessary -- leave door off
Post by Oldfeller2 on 07/10/07 at 13:54:19

Found out something BAD real quick about putting your air box door back on and sucking ALL the air down the relatively small desnorkeled center top air passage -- it makes a hell of a wind tunnel effect that blasts directly at the top edge of the air filter piece.  

The leaf-blower like wind force of a closed air door is enough to start to peel and separate the layers of the nu-foam apart and fold them back, one layer at a time.  This is NOT good.  Luckily, mine did not get very far before I noticed it.

Now I think I know why the snorkel was in there in the first place -- it directed the leaf-blower like wind force directly down against the plastic bottom of the housing and broke it all up into eddies which then got sucked into the intake.

I am going to put in a new, un-peeled filter element and use a needle and thread to go lightly around the outside edge of the filter material about a quarter inch from the edge.  I will not pull the thread down tight, but I will pull it down some to make sure any air jet action can't move the layers around or cause them to separate, etc.

I will also go back to leaving my door off the airbox -- the vague threat of some dirt isn't worth FACT of leaf blower air channel forces peeling the filter element apart.  With the air door gone air comes in more gently from all directions, not funneled forcefully through only one focused place.  I had no issues with over a week with the air door off -- got issues with it in place in just two days.


Short-term Solution:  use relatively more thread to tie the air filter down to the screen.   I ran a loose half inch stitch seam around the entire edge of the filter a quarter inch back from the edge to make sure nothing could ever peel or separate again.  I also left my air door off again -- air comes in from all sides more gently that way.   This seems to be working OK in the short term.  WORKED OK LONG TERM TOO


Long term solutions suggested by other members:  

1)  Put a piece of nylon stocking leg over the entire assembled air filter.  This sounds neat if you got the tighter part down near the foot and it would prevent delamination of the batting material.

2)  Put a piece of hardware cloth over the batting material.  Tie it down with screws into the sheet metal frame to keep the batting in place.  

3)  Go back to the knit-witches and buy some 2" thick batting and a 4" long standard headed sewing needle and just stitch the 2" thick batting to the screen with stitches that only pull the material down about half way.  This gives you lots of retention force and greatly increased dirt collection capacity and gives you a filter you can take out once a year and wash out in the kitchen sink using hot soapy water and then run lots of hot clear water through it to get all the soap out before drying it with a towel and re-oiling it.


You ARE going to have to re-tune your air screw for the lessened air resistance that comes with this filter.   Wait a week or so until your bike has digested any extra oil that you put in the filter (the oil gets on your CV slide and makes it act "odd" for a short period of time).

WARNING: and to quote Lancer -- if you have to turn the air screw out over 3 turns and your idle speed is still increasing then you need a one size larger midrange jet.  Don't leave your air screw turned out more than 3 turns or it can vibrate loose and fall out of the carburetor.

Mine became happy at 2 3/4 turns out, my 'run up' hesitation went away and my power increased yet again.  Bike spits more than it used to, but that comes with the opened airway turf apparently.   Backfires are still very rare, about like they were before I put in the batting filter.


Title: Re: Inexpensive high performance air filter
Post by Oldfeller on 05/20/08 at 11:27:27

One year follow up on the base idea, with six months since last opened up and looked at.  This is the thicker 2" polyester "Newfoam" batting material sewn down into the gutted stock airframe using black thread so you can see the sewing pattern.  Batting was collapsed by the sewing from 2" to 1 1/2" and it looks like it settled another quarter inch or thereabouts due to air suction going through it (leaf blower effect).

Intent to this generation of trick was to come up with a Gunk engine cleaner washable (in the kitchen sink no less) very durable re-oilable air cleaner that has the characteristic high air flow & low air resistance of a high performance air filter while combining a very low initial cost, better than stock air particle filteration and a robust reliable/durable nature in the face of motor blowby fumes, sand, dust, etc.

This is the third evolvement of this cheapie filter idea and I do believe it is getting close to meeting all its goals.

This filter element has been in place for a solid six months run, so it has had time to get all dirty and gritty.  Let's see what we got here.

Well, we've got a hell of a dirty mess -- my home town has lots of sand and dirt in the air and we've had a plenty of land clearing, road and other forms of bulldozer work to kick up plenty of dust and dirt that I had to dive through.  

Note the free oil from the motor puke tube that has accumulated down inside the airbox -- this was about a half ounce of oil that I let out of the little stoppered drain tube after I took this picture.  You need to remember to unstopper and drain this tube every time you drain your oil, BTW.

First question:  Does Mazola spray oil (Pam like stuff) evaporate out to be all sticky and gummy-like and does it catch sand and grit and dust and HOLD on to it like nobody's business?

Yes, it is yellow, sticky and holds on to what hits it.  These are full size grains of sand sticking to a smooth plastic surface because the oil won't let go once it gets hold of something.  

The yellow spray on Mazola fry pan anti-stick oil seems to work as a filter conditioner oil just dandy, thank you very much.  Does it really stick around on the polyester filter fibers though?

The oil is yellow and you can see it "sticking around" very clearly on both the top and bottom views, so I would say it does stick around and continue to do its job even after 6 months of sucking air through it.

Now, final and most important question:  Did anything (no matter how fine) get past and through the filter batting & Mazola oil combination?

These top and bottom images are HUGE images that you can only see a corner of it here on the list without scrolling the scroll bar at the very bottom of the whole thread.  

To answer this question completely for yourself, right click on the image, "save the image as" and save the full size picture over to your desktop then blow it up 800x with your favorite image editor and look 'till your hearts content.  You can do the same thing on the dirty side picture and like me you will conclude that air borne dirt doesn't even get very deep into the dirty side before running into a gummy oil coated strand and getting captured and held.  On the dirty side I can see down into the batting far enough to see clean white strands sitting there waiting for some dust to come see them.

Having torn apart the last one inch polyester batt version and finding that the finest dust didn't penetrate but a quarter of an inch, I think this slightly compressed 2" version has twice more fibers per inch and a good bit more depth in it to do an even more through job of stopping the finest dust and filth for an extended period.

Looks good to me, I put it right back into place UNTOUCHED to finish out a full year of use before looking at it again.  It didn't need washing yet.  I did not even add any more Mazola spray oil to it (it still had plenty of unused undirtied liquid yellow oil still trapped in the batting, easily visible from both sides of the batting)

Test continues .....    ;)


Title: Re: Inexpensive high performance air filter
Post by Oldfeller on 01/31/09 at 08:05:13

Pulled it out, looked at and put it back in.   White side is still white on 1/31/2009.  

Dirty side has lots of clear space between fibers still.  Gummy oil is still catching the dirt before it goes very deep into the thick filter.  This is working out better than anticipated.

Title: 3-14-2009
Post by Oldfeller on 03/14/09 at 12:30:35

Diamond Jim reminded me my air filter was still there so I thought I would check on it and take some pictures.  Main question was "Had any fine stuff made it through the compressed 2" thick batting yet?".

First, some shots of the  filter dirty side with pushing 2 years worth of dirty stuff from the air flow impregnating it  Although the weave of the fabric is still open and passing air without impeding the flow you gotta admit, it sure is DIRTY on the dirty side.

Now that is pretty dirty looking stuff on the dirty side.   Surprising thing is that nothing much made it through to the back side of the filter.  The oil soaking everything has gotten a little dingy looking, which is clearly shown in this picture compared to a brand new filter element.  Careful examination with a magnifying glass showed no particulates, but the oil looked a little off color (remember, it was a clearish yellow to start with and it is now a dingy tannish color).

Did the yellow clear oil change color or is it starting to pick up supremely tiny fine particulates all the way to the back side of the filter finally?   I wiped the back screen of the filter with a clean white Kleenex tissue to see if anything was physically there on the back side of the filter.  

<note: this is a BLOW UP picture -- the scroll bar is at bottom of this post>

The oil is darker and isn't a nice yellow any more, but it still seems to be a clear oil and contains no discernible solid matter.  It penetrates the Kleenex and darkens it very slightly as seen in the picture.   Originally the yellow canola oil would yellow the Kleenex in a similar fashion, so I would say the oil has oxidized and changed color some from passing all that O2 laden air through it over the nearly 2 years it has been in service.

I put the clean side up and sprayed more yellow Mazola frying pan spray on the back side of the filter and let it soak into the mass of fabric, then I left it overnight so the volatile carrier could evaporate and turn the spray back into its sticky wonderfulness.   I did this rather than cleaning the filter mass and respraying it simply to see what would happen.  After all, it isn't like the fibers are blocked with dirt or anything.  They are simply dusty on one side and still clean on the other side.   The oil itself had oxidized some, but that just needed some reinforcement with some new oil, applied from the clean side and carried by gravity to re-wet the dirty side.

Back in she goes, after nearly 2 years of use it still hasn't allowed any appreciable numbers of particles of dust or dirt to penetrate the whole thickness of the filter.

Not to shabby for $4.00 ....  good filtration and excellent durability too.  

Plus it proves if you choose to you CAN refresh the sticky yellow oil from the back side without washing the filter -- the oil migrates through down through the filter mass and renews the trap oil on the front side without allowing the mess to move back upstream towards the back clean side.   You CAN oil up the dirty fabric strands -- the dirt already trapped on the strand gets turned into little filter "sub-fingers" to reach out and trap new particles even more effectively than the bare smooth fabric strand could do originally.


Title: Re: Inexpensive high performance air filter
Post by Oldfeller on 03/14/09 at 13:04:05

Another thought -- the blow by from the head vent tube dumps crankcase blow by vapor into the air box.   After 2 years, could blow by have sullied up the clean side of the air filter with some nasty dark blow by gasses?

How many small backfires have hit the clean back side of the air filter in two years?  More than a dozen, I would guesstimate.  

Enough to dirty things up a little bit?  

Mebbe so ...  mebbe not.    I dunno.

Go figure.  

If I had lubed it with a darker oil (say K&N dark red spray oil) I wouldn't be having this discussion because I couldn't have noticed any difference in the tint of the oil had taken place.  The clear yellow coloration of the Mazola spray oil was a good pick because of the color as well as the inherent extreme stickyness the stuff possesses.

In any case, the clean side of the filter is loaded up with a fresh load of pretty yellow Mazola frying pan spray and it looks all  "yellow sticky new" again.  

The $4.00 filter is still working and it goes back in for another summer's worth of dirt and pollen and other forms of air borne crap.


OK, here is a quick summary of 3 years worth of additional experiments with heavier oils compared to PAM or Mazola spray cooking oils fits in right about here.   I tried the heavier gear oils and found that they are more mobile than the cooking spray -- it took a year for the stuff to try to run out, but it happened.

Cooking spray doesn't move on you and it has another benefit -- the yellow coloration lets you readily see that contamination has progressed xx distance into the matting, allowing you to pull and clean it in a timely fashion.

The dark gear oils, etc. did not offer this visual advantage.    So, the cooking oils get the nod as "best stuff to use" and you should plan to check the thing at least once every year or so.

Title: Re: Inexpensive high performance air filter
Post by Oldfeller on 09/10/15 at 07:21:35

First post in this series was 2007 and it is now September 2015.  

8 years of testing, with three filter element changes (so I could delaminate them to see how far dirt got towards the inside) with this last element being in there for the last 5 years now.

What prompted this check was a Garmin led adventure on some black lines on this past Dragon trip that turned out to be mostly unpaved -- 30 miles of rough, bumpy dusty dirt roads and I was riding tail end charlie position with my engine eating all that cloud of red dust.  

It was so bad Moderator Dave was kissing the pavement when we finally found some, and I was repeatedly beating on my pants legs to try to get the solid red layer of fine dust off my clothes.   The bikes were a right mess, lemme tell ya.  

I thought then, hey, it's time to check that air filter element when I get back home.


First pair of shots are how it looked "as removed" from the bike    There is considerable red/brown dust caked on the front of the oiled element and some signs of penetration into the filter mass.

Obviously nothing much is getting through the filter, so lets check on that theory by doing the air box contamination check.   This involves squares of toilet paper wiped on the pre-filter air box surfaces and another one wiped on the post filter air box surfaces.

OK, the square on the left is solid with red/brown dust and very very dark and gritty.   The one on the right shows the standard oil coloration and was very light and smooth and felt like oil.    (you need to slide the slider over at the bottom of the post to see the right hand toilet paper square)

The air box itself shows that nothing grit or red dust based is getting through the filter element.

As we all know, oil is present inside the air box because the huff tube dumps oil mist laden blow by into the air box itself and the oil mist winds up pooled in the bottom of the air box and all over the interior air box surfaces.  


I plan to keep on using this same filter, but I need to augment the oil in it some.   I apply petroleum jelly to do this, on the upper quarter of the filter on the dirty side, forcing it into the matt some such that it will "open up" and pass some air.   This particular area is subjected to the air blast from the seat area and it is the first area to go dry.  Is is also the top of the matt as it sits in the air box, so gravity will move lube placed here downwards while the air motion through the filter moves it into the filter matt.   Lube this area good and you have lubed the whole filter (over enough time of course).

By using petroleum jelly to re-lube this area I give it a maximum sticky and maximum "stick around some" lube that is compatible with the base oil load in the filter proper.

On the clean side, I apply two through sprayings of CRC Belt Conditioner -- this goes on thin and clear,  "washes" the clean side all white and clean and then sets up into a very tacky, sticky, glue like film on all the washed fibers.   It is compatible with the oil used originally and "sticks around" wonderfully (which is exactly what it does on your "V" belts too, now isn't it?).  

The fine fiber dirt it washes free rejoins the oil pool on its slow slow trip to the huff tube pool -- so by "washing" the inside surface I essentially make the filter clean and new again, except where it is already perfectly justifiably "filthy dirty".   And I add greatly to the sticky factor while doing so.

It is my theory now that eventually all heavy oils (and yes, petroleum jelly is just a thicker than normal oil based product) will move down through the matt and drip down into the oil pool from the huff tube, carrying the trapped dust with it.

However, this system has proven it will remove fine fine dust without clogging up as the fine dust is caught by the oil and migrates down to the huff tube pool and gets drained by the drain tube at oil change time.

I have also now shown you a way to maintenance this filter system without taking it apart and replacing the element all the time.    

BTW, this "clean and re-lube without replacing" system appealed to ol' Master Yoda quite a bit, it did.   He actually returned my light saber to me again and he is actually giving me Force Lightning lessons now to show he thinks I am finally finally "getting it".

:)     .... that force lightning stuff stings a bit, ya know --- 'ol Yoda, he jest keeps on tossing it at me and I try to catch as much as I can of it ....  
..... but it stings, yes indeedy, it certainly does .....    yeeeeowie !!!

http://  ... hee hee .... stupid paduan, take that !!!!   Electro-stimulation opens  synapses,  help pitiful brain grow quicker, it will .....

Title: Re: Inexpensive high performance air filter
Post by tensleep80 on 09/10/16 at 15:22:38

This is good stuff!!  I wonder how aerosol chain lube would do?  It is designed to stick to metal chains and may slow the phenomenon of gravity migration?  However, there is certainly a coolness factor to using a cooking product.  Thanks for sharing - the longevity of this system is proof enough for me.  I will have to try this as I resurrect my project.

Title: Re: Inexpensive high performance air filter
Post by Franklin2135 on 11/20/17 at 10:34:30

I'm going to give this one a try. Matter of fact, I've already bought the foam, cut it to fit, and stitched it to the old air filter screen after cutting the paper away (tough stuff, that). I'll apply the spray a week or so before I put it in.

I'm not doing a muffler change right away, so I'm thinking I'll leave the door and snorkel in place for now, unless there's some benefit to removing them before the exhaust is less restricted?

Title: Re: Inexpensive high performance air filter
Post by GT61 TURBO ZX14 on 01/20/18 at 15:56:34

Did you flow test it ?

Title: Re: Inexpensive high performance air filter
Post by nablats on 10/07/18 at 13:11:25

Hi All from Yorkshire - re- keeping crud out of the motor - an old competition bike tip was to rub grease round the airbox - that catches a lot of muck for very little buck... ;D

Title: Re: Inexpensive high performance air filter
Post by Beerm8 on 10/10/18 at 20:54:23

I have had good luck with your filter mod useing stiffer hardware cloth bent to grip the metal and then tacked with small dabs of automotive goop to keep it in place.  No sewing required :D

Title: Re: Inexpensive high performance air filter
Post by Beerm8 on 10/10/18 at 21:04:21

also, wetting the paper filter before you pull it out helps.

Title: Re: Inexpensive high performance air filter
Post by DragBikeMike on 10/24/18 at 11:47:51

I have not been able to find the Fairfield "Nu-Foam Polyifil", have only been able to find Fairfield "Polyifil Project Fleece".  The Project fleece is not one-inch thick.  It's about one-eighth inch thick.  So if I use 16 layers of the Project Fleece, will it be equivalent to two layers of the Nu-foam?  Is it the exact same material, just thinner?

Title: Re: Inexpensive high performance air filter
Post by Beerm8 on 10/26/18 at 16:35:11

found mine at Hobby Lobby with the pillows.  They had 1" and 2" packages. » Powered by YaBB 2.2!
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