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Author Topic:   Air filter question
Eljojo
Dirt Forum Champ
Total posts: 968
posted March 05, 2005 05:36 AM  
I have, for the past three years, run a 3" Amsoil air filter. I really like the way it seems to filter, but it's getting worn and I have always been curious about it's efficientcy on those really dusty nights. You see, I use one of the nylon "Outerwear" covers and a little oil bleeds from the filter into the cover. After a race the "Outerwear" is caked with dust! Is enough air getting thru the cover to the filter and on to the motor? I thought about going to a taller filter, called Amsoil, and the one I have is "it." I have also seen a "True Flow" filter advertised at www.daymotorsports.com. This is another foam type filter, which is avaiable in 3" 4" and 5" heights. Have anyone got one and what do you think about it? I am sold on foam filters, but I'd like some advice/experience before I switch brands. Thanks!

iowatoolman
Dirt Freak

Total posts: 369
posted March 05, 2005 06:18 AM  
i was told NEVER USE AN OIL FILLED AIR FILTER ON DIRT TRACK RACING the oil traps the dirt and you can never get it clean as well as not enough air flow (later in the race)

just what i had been told

drive hard or drive home

rico 08
Dirt Forum Champ
Total posts: 1139
posted March 05, 2005 06:25 AM  
I use a paper filter that comes with the foam outerwear aready on it..i think it's for a 7.3 ford diesel...
I may give up a little flow wise but the engine really looks good at teardown.

sdracer12
Dirt Maniac

Total posts: 180
posted March 05, 2005 07:09 AM  
[QUOTE]Originally posted by iowatoolman:
i was told NEVER USE AN OIL FILLED AIR FILTER ON DIRT TRACK RACING the oil traps the dirt and you can never get it clean as well as not enough air flow (later in the race)[QUOTE]

The reason you SHOULD use an oiled filter like a K & N is right there in your statement. The oil trapped more fine dirt in the element. So the dirt didn't get into your motor, right? As far as cleaning, if you do it right, they get just as clean as new. I'll give up a tiny bit of airflow anyday to know that I am stopping as much junk as possible from getting into my motor.

The biggest help to your air filter is maintenence. If you have an oiled cotton filter like a Rush or a K & N you have to clean it regularly, sometimes after every race. If you use a paper element, throw it away OFTEN, and replace with new. Run an Outerwear, it does help.

[This message has been edited by sdracer12 (edited March 05, 2005).]

goinrcn44h
Dirt Freak

Total posts: 205
posted March 05, 2005 10:34 AM  
Properly oiled and using proper oil , a foam of any style will filter the best as well as flow the best air numbers over anything in almost any application. end of story. if you run on dirt, and you don't HAVE to clean your filter after every race, that alone should be telling you something. Next best option is a lightly oiled K an N with a foam outer layer with proper foam air filter oil. Proper foam oil will dry in a few minutes and be left very stringy and sticky, it will not run off or pull into the engine. if it does, you are usin the wrong stuff. Check out the motocross products, they are the worst for eliments and they also use foam, the japanese are far from idiots in this area and thats what comes standard on all MX bikes. I raced moto for 14 years and this is another area that motocross is worlds ahead of any car racing.. wanna see shock technology.. or many other areas...
44H

akadirtracer7
Dirt Freak

Total posts: 217
posted March 07, 2005 09:32 PM  
Been using amsoil for about 4 years and think they work really good.Both filtration and air flow. But like everything else needs to be maintained.

racer17j
Dirt Forum Champ
Total posts: 5390
posted March 08, 2005 10:42 AM  
Have been rading a bunch of places where a lot of engine buildersa say paper is the best. Will filter better than a Kand N and wont restrict airflow. I have though about trying it to see. Just hate the thought of changing new filters every couple nights, but if it saves wear on the engine it would be worth it.

strstckracer
Dirt Roller

Total posts: 23
posted March 08, 2005 05:14 PM  
Take a K & N filter and a paper filter apart and breathe through each. You'll never run a paper filter again.

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted March 08, 2005 05:34 PM  
Thats my point the paper filters better, saving wear on the engine. Now it might take a bigger overall filter say a 14X5 instead of 14X4 but in theory you should be able to get the airflow you need through paper just as well as guaze, foam or whatever. Ea square inch might not flow as well but overall airflow is what your looking for.

jay116
Dirt Freak

Total posts: 428
posted March 08, 2005 06:10 PM  
We are talking about racing here right..? and in racing do you not want the most , along with the best performance..?
foam has zero restriction, it only changes the direction of air. paper is the worst, and adding a bigger paper filter will accomplish nothing. unless you are talking a turbo powered vehicle of course. but in a normally aspirated engine, it is sucking air, if its fighting a restriction, you are getting less air.. period. it takes air to make horsepower, plain and simple.
44H

zeroracing
Dirt Forum Champ
Total posts: 1876
posted March 08, 2005 08:19 PM  
new propower racing motors use paper, and replace them often. propower said the motors look better when taken apart, and turned similar numbers on the dyno.

mdsteacher
Dirt Maniac

Total posts: 145
posted March 08, 2005 08:42 PM  
We've had very good luck with 3" paper filters changed every 2 nights. Had a K&N but found it a big hassle cleaning it, oiling it, letting it dry, etc. It seemed my time could be better spent elsewhere. I've seen goods and bads for both and I've seen more and more racers using paper. K&N was used for ashpalt racing originally (drag racing).

bryanb30
Dirt Freak

Total posts: 243
posted March 08, 2005 08:55 PM  
i use paper with a foam outer.....id love to see some dyno numbers of diff. filters

sdhnc29
Dirt Forum Champ
Total posts: 934
posted March 08, 2005 10:10 PM  
We've used paper filter's for year's, and recommend them on every engine that we build. Our testing and "on track" testing is in total agreement with Pro Power's. K&N does advertise extremely well though This conversation is like every other one on this board, in relation to oil brands, oil filter brands, etc., etc., etc. Bottom line for me on any of these subjects is to use what your engine builder recommends. We have generally researched every way to make horse power, keep our product's running reliably, and keep our clients from spending a small fortune on every freshen-up.

I was at a rather large and rather well know Cup shop a couple of week's ago, and noticed they had a lot of Wix boxes laying around.

Steve

------------------
Hendren Racing Engines
Rutherfordton , NC
(828)286-0780
http://www.hendrensracingengines.com

iowatoolman
Dirt Freak

Total posts: 369
posted March 09, 2005 08:26 AM  
not that i disagree pound for pound making power use a K & N ... but you might want to read the information on k & n 's website here is the link
http://www.knfilters.com/facts.htm#OFFROAD

drive hard or ddrive home

dluna
Dirt Freak

Total posts: 334
posted March 09, 2005 08:34 AM  
Who makes a good paper filter that wont cost an arm and a leg to change every 2 or 3 races?

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted March 09, 2005 09:41 AM  
wix 42096 or napa 2096 I beleive

Steve,
I am thinking about giving paper a try. I stillplan on running the outerwear to try and knock out some of the bigger stuff. Then I was thinking of blowing the filter out every night and changing the filter every other night depensing on what it looked like. Does this sound reasonable or will it need to be changed more ofter?

[This message has been edited by dirtbuster (edited March 09, 2005).]

GO 24
Dirt Freak

Total posts: 366
posted March 09, 2005 11:45 AM  
We use Wix & outerwears.

NJantz
Dirt Forum Champ
Total posts: 755
posted March 09, 2005 12:37 PM  
Flowrate and filtration are pretty simple. You can't have both! The more cfm the filter will flow, the less filtering that takes place. Nobody has figured out a way to cheat science yet. Do a comparison test next time you're on the dyno and find out which one makes more power. I checked on the Wix/NAPA Gold air filter #2096 and found that it flows 345cfm. The K&N flows quite a bit more.

One thing I would question regarding the K&N filter: Does the flow rate of their filter remain consistent over time as it gets used and cleaned time after time. I doubt you can ever get all the dirt and oil out of it. I'd imagine it would build up and restrict the flow as time goes on even though you might be cleaning it on a regualar basis.
[This message has been edited by NJantz (edited March 09, 2005).]

[This message has been edited by NJantz (edited March 09, 2005).]

mdsteacher
Dirt Maniac

Total posts: 145
posted March 09, 2005 01:51 PM  
Dirtbuster, we run the 3" Wix/Napa paper filter with outerwears pre-filter and change it every 2 nights regardless of what the filter looks like. Plus, we change the outerwear pre-filter twice each season (plus clean it every so often). Find a parts store that will let you buy a dozen air filters at cost. It is worth the few extra dollars to replace on a schedule rather than using other factors.

Todchester
Dirt Roller

Total posts: 23
posted March 11, 2005 06:15 PM  
Most air cleaner set up's I've seen **** more dirt from mounting surface and stud hole than any filter could.. as long as it does not have a hole in it. I guess what I'm saying some thought on all aspects of the air cleaner need close attention to get the best results. In the end though it is like hp. with mpg. the two work against, not with each other.

akadirtracer7
Dirt Freak

Total posts: 217
posted March 11, 2005 07:57 PM  
If 7-8 bucks every 2 to 3 races .Its alot cheaper than a new motor.Maintenece is the key to any filter.We run about 20 races a season so you spend less than 70 bucks for a season for fliters do you try to strech your oil filters or run junk filters. Wix is the way to go napa and car quest are also wix filters.

Ego Racing
Dirt Forum Champ
Total posts: 724
posted March 11, 2005 08:21 PM  
quote:
Originally posted by sdhnc29:
We've used paper filter's for year's, and recommend them on every engine that we build. Our testing and "on track" testing is in total agreement with Pro Power's. K&N does advertise extremely well though This conversation is like every other one on this board, in relation to oil brands, oil filter brands, etc., etc., etc. Bottom line for me on any of these subjects is to use what your engine builder recommends. We have generally researched every way to make horse power, keep our product's running reliably, and keep our clients from spending a small fortune on every freshen-up.

I was at a rather large and rather well know Cup shop a couple of week's ago, and noticed they had a lot of Wix boxes laying around.

Steve


I am not sure about now but I do know that K&N was illegal in NASCAR. It seems you can spray the filter element with NOS and get it on the car quickly and it will leak out into the air flow slowly. We tried it on track with the tracks help and found we were about .25 seconds a lap faster on a 5 lap run. After timing it by the lap it was a full second faster on the first lap than a normal K&N and it went down hill after that. This was on a 3/8 mile fast asphault track. After about 6 laps the times were right back into our normal times again.
We always thought it was a little funny that after trying this 5 times it always went away after 6 laps or 2.25 miles. just under the size of the larger Nascar Tracks. So 1st lap would be fastest and one final lap to make sure the filter was purged from it.

highside2020
unregistered Total posts: 724
posted March 11, 2005 09:33 PM           send a private message to Ego Racing   Edit/Delete Message   Reply w/QuoteBBBBBB
Another trick is to spray some nos on the element and frezze it. I have seen several teams in the southwest here get caught with frooze elements before there qualify runs.

crc1124
Dirt Maniac

Total posts: 143
posted March 12, 2005 08:35 AM  
With all these different opinions what is most important engine maintenance or a small amount of lost cfm? I think it's being a little lazy not taking the time to clean your k&n air filter properly. It takes time to change the oil and fuel filter too but do you take shortcuts on that too. I'm a firm believer in K&N. Their job is to stop the most minute dirt particles from entering into your engine while giving you the best airfow possible. I would really like to see a test after a night of racing and see how well each filter worked. The paper filters were designed for "normal" everday use. K & N filters and other RACING filters are designed for racing! Compare it to say engine oil. You can buy the cheapest oil that Autozone sells or you can buy Royal Purple. Under racing conditions which one would you trust? Do you guys buy the cheapest oil filters out there? So why would you don't you do the same for your air filter? It's as important as all the other filters. Sure you "might" lose a little cfm with the oiled filters but you lose a little horsepower with a heavier weight motor oil. I think we spend way too much money on these cars to buy a cheapie air filter. On a street car they do fine, but on a racecar?

Eljojo
Dirt Forum Champ
Total posts: 968
posted March 12, 2005 07:20 PM  
The original question was: does anyone have/use a "True Flow" foam filter?
The debate was not about what is the most economical (cheapest) or the easiest to use filter------it has been about which filter is the most effecient! I believe in the foam (oiled) filters. I see so much dirt on mine that I question that it has changed the air/fuel ratio. Do you see that happening to your K&N? Do you have that concern about the paper filter? Do you think my air is more contaminated than yours?
I just want to improve on the amount of filtered air I put into my motor.

Blackgold
Dirt Full Roller

Total posts: 71
posted March 12, 2005 09:41 PM  
I don't know the numbers for flow on any of the filters, but I have complete confidence in the paper filters as an efficient and good filter medium. I myself don't want to mess with washing and oiling filters. For some reason John deere, Cat and all other farm and construction equipment manufactures put paper filters on their equipment, and it's not uncommon for these engines to run 12-15 thousand hours without an overhaul. Many times we run in conditions so dusty that you can't see the ground 10 ft. in front of you. Most automotive filters have plenty capacity to allow quite alot of dirt build up before choking an engine. JMO

akadirtracer7
Dirt Freak

Total posts: 217
posted March 20, 2005 06:09 AM  
Eljojo I'm with you if amsoil had a 4" filter i'd be using it .If this foam filter works that your looking at let me know where you got it at.

Istock66
unregistered Total posts: 217
posted March 20, 2005 07:15 AM           send a private message to akadirtracer7   Edit/Delete Message   Reply w/QuoteBBBBBB
John, I run a K\N. I also run a pre filter around it, the cloth type not the thick foam one.

Im not sure what filter your thinking of running. Ive seen one with the outer a coarse foam and the inner a tighter foam. I personally would think oiled they would be restrictive, and they also dont have the pleats like a k\n so I wont be changeing.

I clean the outerwear every week with hand cleaner and dish soap. My filter very seldom gets really dirty so I clean it every 5-10 races.

I have put a same sized wix paper on my motor before and it idled lower right then, so I know it is more restrictive. Ive also seen cheaper paper filters **** the top down.

The inside of my k\n filter never looks dirty, my cylinder walls on the motor I ran 11 times last year on dirt didnt have ANY contaminant scuffing. A motor I ran for 3 years on pavement looked new still with this same filter set up.

I never see dirt sitting on top of my carb like I did with a paper years ago, which was why I switched immediately.
It doesnt take but 5 minutes to clean the filter. simply spray the cleaner on, let it sit, and hose it off from the inside out. let it dry till the next day and use a paint brush and put the oil on. I bought a gallon of cleaner and oil in 99 and havent used half yet.

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