"State of the art" in high-efficiency filtration

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It seems that there are a plethora of air filter makers out there making products that promise to reduce restriction and increase flow rates, producing better power and a more noticeable induction sound. These include high-performance companies such as AEM, aFe, Airaid, Injen, K&N, True Flow, and others. Some OEMs, such as Toyota's TRD division, even make so-called "high-performance" filters.

There are also many companies competing for the standard filter replacement market, such as Fram, Purolator, Wix, and others.

In the heavy-duty market, Donaldson has interesting products based on synthetic media. Amsoil brought some of this media to the passenger car and truck market with their Ea filters, but those seem to have been discontinued for some reason or another.

My research thus far has indicated to me that these OEM filters are typically the most efficient in filtration, but I thought it would be worth further investigation. After all, the oil filter market has seen a recent proliferation of products with synthetic, wire-backed media that allow for superior flow and filtration relative to the previously-ubiquitous cellulose media.

My question is therefore: does anyone know what the state of the art in filters these days is for customers who want the best filtration available, or are we still recommended to go with the cellulose OEM filters over any other option?

If better options aren't available, is it because there seems not to be much of a business case for making better products or is it because the characteristics of an air filter, and the lower pressures they operate at, allow for cellulose to shine in ways that simply aren't available in oil filtration? In a naturally aspirated engine, the intake manifold pressure presumably never exceeds atmospheric (~14.5psi). Based on restriction gauge usage, air filters are considered clogged well before they reach even 1psi of pressure drop. By contrast, oil systems regularly run at 30-40psi (higher at startup) and, as I understand it, bypass valves are set to allow for 10, 15 or even 20 psi of pressure loss across the media, depending on the application.

I can understand why there might not be as much of a business case for air filters as oil filters; there's a greater variety of airbox designs, they don't get changed as frequently, and - from the efficiency numbers I've seen bandied about for OEM filters - there simply doesn't seem to be as much room for improvement. Yet I am certain that I cannot be the only person who would be interested in a higher-efficiency, better-filtering product; surely someone in the market caters to people like me?

Thanks in advance for any input anyone might have.
 
1 psi = ~28 in of water, about 2X the allowable restriction in a gas engine filter.

0.5 psi / 14.8 psi = roughly 3.3% loss of intake air density and performance.
If the intake air has strong pulsation the performance loss can be a bit greater.
With 4 or more cylinders it's not significant. A multi carb setup (love those Webers!) with a filter for each cylinder or two is a different story.
 
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That's not quite what I meant - I agree completely that the air filter barely causes any meaningful restriction in performance, and that buying a high-flow filter to put in the stock housing is likely a fool's errand.

What I was curious about was whether there exist filters that are more effective at removing dust, dirt and other debris from the air when compared to the typical OEM paper filter.
 
I wonder the same thing. Yes, we already have all kinds of options for "higher air flow," whether we actually need it or not. We can get bypass oil filtration, high end full flow filters, and so on. Yet, what kind of real efficiencies are we seeing with what we'd consider ordinary, replacement air filters? As far as I can tell, assuming that each product fits correctly and isn't a build quality nightmare, I cannot differentiate between any of the major players, the minor players, the Chinese knockoffs, and the OEMs products.
 
Originally Posted By: Garak
I wonder the same thing. Yes, we already have all kinds of options for "higher air flow," whether we actually need it or not. We can get bypass oil filtration, high end full flow filters, and so on. Yet, what kind of real efficiencies are we seeing with what we'd consider ordinary, replacement air filters? As far as I can tell, assuming that each product fits correctly and isn't a build quality nightmare, I cannot differentiate between any of the major players, the minor players, the Chinese knockoffs, and the OEMs products.


+1
 
Amsoil still makes the EaAU "Universal" cone filters. They stopped making the ones for stock applications because of the amount of filters they had to stock was exploding. Though, it would be nice if they added a couple sizes of round ones for carb guys.

Im not sure on the better filters available currently. I haven't looked at it in awhile. When Amsoil discontinued the EAAs I bought a couple for my applications so I haven't been too concerned.
 
I think your question is excellent. I have been seeking the same high efficiency filter as you. My thought process is much more primitive though. The question that comes to mind is what methodology are we going to use to measure filter efficiency?

Dave
 
Originally Posted By: David_Corbett
What I was curious about was whether there exist filters that are more effective at removing dust, dirt and other debris from the air when compared to the typical OEM paper filter.


One straightforward strategy would be to increase filter size and surface area, to reduce restriction without reducing efficiency.
Even add another layer of filtration for more efficiency, with even more surface area to keep restriction down.
 
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State of the art = Donaldson PowerCore filters. Exceptional efficiency with extended lifespans and flow (due to surface area).
 
The Powercore series is the most efficient in air flow and cleaning air, but there aren't any for smaller cars. The D08 series fit inside many pickups, but really only good up to about a 3.0 engine. With some playing you can get the D09 series into some of the 4.2 Tundras. I change out my series D08 powercore elements in high dust conditions about every 120,000 miles in my 3.5 Toyota T100 (currently close to 400,0000 miles), and haven't changed the element yet in my 2.7 Toyota HiLux, where it has been for about 300,000 km of it's 480,000 km life.

I have fit the D08 into several smaller cars by moving the battery box or other things. Popular for some of the taxis that service the farm communities around here.

Also super efficient, but not made for cars (too big a variety) is the Donaldson's Ultra-Web. It is cellulose with a nanofiber covering. We use it a lot in trucks.
 
Widman, if you're referring to the PSD-series filters, those are some seriously impressive-looking pieces of equipment! You're right that it would seem to be quite difficult to fit those into a passenger car.

It's a shame (for me) that you're in Bolivia; it would seem that upgrading the air filtration system would be a good way to get more life out of my car, especially since my driving sometimes does involve dusty, unpaved roads.
 
You know what I just realized? Ford Powerstokes use powercore since 2003, but a lot of people take them off and put on cone filters. Sometimes they put the factory box for sale. There is one on ebay for $40 from a '09 Im super tempted to buy. The MAF is different plug, but it might be possible for me to adapt it to my harness and then make a transfer function for the PCM manually.
But even if you were putting one on a Non-Ford, you could just ignore the existing MAF no problemo.
 
Yes, my 2003 Powerstroke came with the Powercore. It does not use the turbines as the kits do, but it is a great filter and long lasting. Some people have no idea what they do to their cars and trucks. I stock the conversion kit for the Fords that did not come with Powercores.

Since 2015 Toyota has been running Powercore filters in their Dakar vehicles. Reports are they were really surprised with the efficiency.
 
Originally Posted By: wemay
Originally Posted By: Garak
I wonder the same thing. Yes, we already have all kinds of options for "higher air flow," whether we actually need it or not. We can get bypass oil filtration, high end full flow filters, and so on. Yet, what kind of real efficiencies are we seeing with what we'd consider ordinary, replacement air filters? As far as I can tell, assuming that each product fits correctly and isn't a build quality nightmare, I cannot differentiate between any of the major players, the minor players, the Chinese knockoffs, and the OEMs products.


+1
+2
 
It's probably a matter of more than adequate filtration from the current paper filters combined with more than adequate air flow as well, combined with extremely low cost.

I suspect it's a situation where the paper filters are kind of at the top of the peak when air flow, filter life, filtration and cost are considered- if you try to improve one of the three aspects, one or more of the others suffer.

I realize that people around here are probably willing to do something vaguely irrational like spend 2x on a filter that filters 1.1x better and lasts half as long, but what's the point? Below a certain size of particle, more filtration doesn't buy you anything (they're smaller than engine clearances and just go right through), and clog up a lot faster, as well as cost more and likely suffer lower flow, either initially, or after loading up with contaminants.

So to answer the OP's question - there may be better filtering products, but you almost certainly give up a couple other legs of the table to get that, for very little gain. [censored], even K&N filters, as atrocious as they are at filtration, don't even make a noticeable difference in either horsepower or longevity to the end user, and any differences are typically only noticeable with expensive lab tests.

FWIW, oil filters are the exact same game; just about any car will run for 250,000 miles on cheap-assed Fram orange can filters, and using super-expensive Mobil 1 or whatever filters doesn't really buy you anything that an end user can actually measure in terms of vehicle lifespan.
 
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FWIW, oil filters are the exact same game; just about any car will run for 250,000 miles on cheap-assed Fram orange can filters, and using super-expensive Mobil 1 or whatever filters doesn't really buy you anything that an end user can actually measure in terms of vehicle lifespan X2
 
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