TO THE PEOPLE RUNNING SPECTRUM STYLE AIR FILTERS......

marmot

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Ya turbo diesels pull a whole lotta air, I always wondered how those weird gasser cone filters worked mounted to the turbo inlet of diesels, I guess we know now. Napa 6637
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that is my next mod on my 7.3 after it is timed and squared away. I do like the retro ats ford logo air box and two stage element but the surface area and filtering capacity of the 6637 makes it a no brainer for 7.3 turbos IMO.
 
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lotzagoodstuff

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Ya turbo diesels pull a whole lotta air, I always wondered how those weird gasser cone filters worked mounted to the turbo inlet of diesels, I guess we know now. Napa 6637
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that is my next mod on my 7.3 after it is timed and squared away. I do like the retro ats ford logo air box and two stage element but the surface area and filtering capacity of the 6637 makes it a no brainer for 7.3 turbos.

I do believe the diesels suck a lot more volume due to compression and the relatively large displacement. I installed the 6637 on my PSD right before I drove from Washington to Illinois and I felt like it was a major improvement over the stock PSD airbox as mine looked like it had lots of room to leak. It sounds better, I can't wait to get my Russ rebuilt turbo bolted on in the spring as mine seems to drink oil when it's cold.
 

Wyreth

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I've had this problem, (not to that extreme tho) with oiled cloth filters in the past.

Went to AEM dryflows. Similar form factor, different filter media. Seems to filter the small dust better than the oil cloth. Also has the bonus of not gumming up your MAF (of course that doesn't matter on our trucks)
 

BDCarrillo

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A large portion of IDI's are N/A, thus my comment was aimed at the bulk of folks...

The way you word things is what rubs people wrong. "Forced induction raises the required CFM that a filter has to handle" would have been just fine.

I have seen, with my own eyes, owned, raced, and worked on turbocharged drag cars with small displacement 4 cylinder engines and large turbos that have destroyed filters by sucking the pleats in and deforming the supporting mesh. Scale up to 3.5 times the engine and even at less boost it's a very high CFM flow (or lb/min).

Also take a look at the OEM air filter on the late model supercharged Cobras. Some are almost a third the length of the engine bay.
 

jay22day

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A large portion of IDI's are N/A, thus my comment was aimed at the bulk of folks...

The way you word things is what rubs people wrong. "Forced induction raises the required CFM that a filter has to handle" would have been just fine.

I have seen, with my own eyes, owned, raced, and worked on turbocharged drag cars with small displacement 4 cylinder engines and large turbos that have destroyed filters by sucking the pleats in and deforming the supporting mesh. Scale up to 3.5 times the engine and even at less boost it's a very high CFM flow (or lb/min).

Also take a look at the OEM air filter on the late model supercharged Cobras. Some are almost a third the length of the engine bay.

Well the thread is about a spectre filter on a turbo truck, original posters truck is turbo. :dunno im not trying to rub anyone any way. If you already know what i posted, then we are obviously on the same page, i was just clarifying for those that don't have quite as good of an understand as yourself.
 

Black dawg

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The max cfm requirement for these engines is suprisingly low

That is some pretty coarse dirt, to get sucked through a filter, regardless
 

BDCarrillo

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6.4 PSD oem style K&N next to a 1 gallon jug, just for comparisons sake. Obviously the 6.4 flows a LOT more air at 40 psi... but still...

A quick napkin calculation says that an N/A IDI needs 850 sq inches of filter. A turbo model running at ~14 psi needs twice that to keep the face velocity in spec.
 
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IDIoit

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Not that you care what i have to say idiot but to those that appreciate good info/advice:

lemme guess' you have a bajillion likes over on hd forums " right" ???

if this is directed at me, i do care! lol

im always open to comments, ideas, and suggestions, but if you go online and belittle people (like someone else posting here)
i have no time for people like that, i have better, more constructive ways to spend my time other than reacting to a "hotshot" on a forum.

this filter had about im going to say 3-400 miles on it, yes it was cleaned when i did my IP swap 2 weeks ago.
i bought a new filter and oiled it... cheapo 20 dollar filter... no good.
i didnt realize they were so bad until i saw this this morning.



i will be deleting the hell out of that cone type filter.
i just put my truck under the knife again, a long list of items im going to be doing.
the air filter will be up graded to atleast one that was previously posted.
doing some tubing work now, so ill be also welding up some 3" and rerouting the filter to a better spot.
may even make a duct from my hood to the "box"
 
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Clb

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Thats a rather poor entrapment of particulate matter in the first pics(PERIOD) for anyones filter.
 

marmot

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displacement has little to do with cfm unless the vehicle is non turbo
Wow, that is so what is the word I'm looking for....I suppose that 2.0 was turning damn near 3000 rpm:rotflmao. You seem to present yourself as a bit of a know it all so if you don't understand basic physics you might want to take a physics course, there are plenty of online courses available. At 15 psi you are effectively doubling the volume of air flow into the intake at a given rpm. That is assuming 1 atm of atmospheric pressure or 14.7psi which is an increase of approx. 7.3 liters for every eight intake events in a 7.3IDI. SO as the rpm increases there is a dramatic increase in air flow that is based almost entirely on DISPLACEMENT (ie combustion volume) and intake pressure. To say displacement has little to due with the cfm of air flowing into the engine is like saying well I'll leave that up to you. ;Really
 

The Warden

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I admit to having skipped some of the comments on this thread, so forgive me if this was addressed and I missed it...

Back when I was fairly new to the automotive diesel world, I was told that any sort of oiled air filter (K&N, Spectre, etc) is not recommended for use on any turbocharged engine. I accepted that at face value and decided to stick with paper filters, so I may be remembering the reasoning incorrectly...however, what I remember was that the turbo puts so much more suction on the filter compared to a naturally aspirated engine that it'll actually suck the oil off the filter element. Then you have filter oil coating the turbo vanes and the filter not filtering out dirt that it should be....which seems to be what happened in this case.

Furthermore, as I understand it, even when the filter is oiled correctly and on a n/a engine, it's still allowing particles of dust in that a paper filter would have stopped.

To be frank, I contend that oiled air filters have their place...on a race vehicle or in an environment where dust is minimal (on a boat, for example). However, for a road and especially an off-road application where longevity's a bigger concern than power (i.e. you're not doing an off-road race and rebuilding the engine immediately afterwards), you're really better off with a paper filter.

FWIW I'm running the stock ATS 088 filter (I found a paper filter element that fits) at the moment, and I'll probably move to the Napa 6637 if I do any intake modifications :sly
 

Trashnomancer

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for starters that was an obnoxious way to disagree. But thats okay, since you don't understand what we are talking about, ill try to explain it. If that doesnt help, try verifying with google, im sure you'll get it eventually.

I see you have a brief understanding that at 15psi your doubling atmospheric pressure. This is a doubling of pressure, and NOT a doubling of flow.

Despite you having said so, PSI is in NO way, a measurement of the volume of air flow



where are you getting this "approximate increase per each of the 8 intake events?"...?....

^^ This is all an "assumption" based on your misconception that doubling PSI is doubling air flow?

Sorry but untill you fully understand how forced induction works, and the differences between psi and cfm, and why these are two completely seperate and distinct forms of measuring two different thing, your not going to understand what I'm properly explaining, so ill stop here.

Im plenty educated in physics and what were are truly speaking about here is mechanical engineering. As a matter of fact i just gave you an brief informative class in turbocharging, maybe next time you'll say "thank you" instead of insulting me. (but probably not :rolleyes: )

***This quote has been edited for pleasantness***

I am likely opening a can of worms here... But I have read this multiple times. and I see you offer no real information to back your argument.

Though it did challenge me to "google it", err... I checked engineering toolbox.

http://www.engineeringtoolbox.com/compressed-air-storage-volume-d_843.html

There example for atmospheric air storage is as follows.
Va = (2214.7 psia) (1.76 cu ft) / (14.7 psia)
Va = 265 (cu ft)

So

Va=(14.7psia)(7.3l)/(14.7psia)
Va=7.3l... duh...

Va=(14.7psi+15psi boost)(7.3l)/(14.7psia)
Va=14.75l

I can see some gas passing between exhaust and intake valves during cycling. But it doesn't seem like that could add up much.

And the individual cylinder cycles may not allow enough time for full equalizing of air pressure between the cylinder and atmospheric. But how much does that really add up to? It seems that with a well matched turbo engine combo, PSI and CFM would basically be interchangeable. In a poorly matched setup or extreme rpm conditions(high or low) PSI and CFM could be more of an issue in comparison. But seeing as IDI's have a very narrow rpm range under working conditions it seems the point is vary moot.

Also not sure how precombustion effects the whole cycle.

If you can find a way to explain with some data, I would love to know better.

As to other things...

When you calculate the Square inch requirements of a filter, that is sq inches of element regardless of how the pleats lye? Or maybe the question should be, does the angle of the element effect it's efficiency?

Likely I will build a custom air intake for my project, and now I am thinking that if I double my air filter space, I half the chances a rouge particle will make it though them. Sound thinking?

The oil getting ripped off of an oil element filter by the turbo makes a heck of a lot of sense to me. The oil is engineered to withstand so much wind shear force, double or triple it and the oil is well past it's engineering. Perhaps a thinker oil? And/or regular reapplication?

Though without the comment from "The Warden" I would have made the same choice, with air flow in mind. I like the larger sized element idea much more.

I grind stones, and just a touch of the finest rouge or rock dust gets past the bearing seals, and spalding starts quickly.

I wonder how much longer X engine would last if built under laboratory clean room conditions, had multiple stage oil filters, and a seriously oversized, possibly multistage air filtration would last VS. the same engine put together under average shop conditions?

I am planning on the clean room route myself. I have one, might as well use it.
 

BDCarrillo

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Trashnomancer: The sq inch calculations require you to measure and count the pleats to figure out the whole surface area available. The lower the face velocity the better, so an oversize filter is never a bad idea, especially as it loads up on particulates. Pre-filter socks are also very effective at prolonging the usefulness of the filter itself, and they can be washed in water and reinstalled quickly.
 

PwrSmoke

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The only thing with lower filtering efficiency than a one or two-ply oiled cotton gauze filter is a cheap-ass, china-made oiled cotton gauze filter.

Oiled cotton gauze is a leftover from the days in the '60s and early '70s when extremely restrictive oil bath and waxed paper air filters (usually too small for the application) could cost you 10-15 hp. In those days, the best filters were in the 93-95% efficiency range and the oiled cotton gauze (OCG) filters could match that and deliver better airflow besides. But everyday filter technology moved on and not only did efficiency improve but so did airflow. And the OE realized the lost potential when making air filters an afterthought so they starting designing better intake systems and using the new filter media more effectively. Today the average filter media can do 97 percent and up into the 99% range (initial... all filter's efficiency improve as they load up). The newer media also allows for much better airflow and most systems now have more than enough airflow to make rated power. the average overage in capacity is around 20 percent so the engine can make rated power with a dirty filter... for a while at least.

And along the way, OCG filters have stayed largely the same. Most are still one or two ply gauze (each ply adds a little to efficiency while decreasing airflow. 2-ply is a good compromise for a street rig in a clean environment). One ply is only to stop the engine from ingesting small birds. Some of K&N's HD truck and off-road applications are 3-ply and have very good efficiency. Airflow is still good but not AS good. In a universal filter, where you are essentially not restricted in size by a filter housing, you increase the filter area to compensate for the increased restriction of the more efficient media. So more of a more efficient (and restrictive) will equal to less of a less restrictive and less efficient media.

What IDIoit has seen, I have also seen and so have others. Dirt passing by an OCG filter. I can't comment on the Spectre brand, but some of the cheap-ass OCG filters are one-ply. I have seen a test of one of these from Australia and the efficiency was appallingly bad... IIRC it was 75%. Some of these internet "deals" are also knockoffs... not the genuine brand name. Buyer beware! My old BUM-V (a diesel Blazer with a Hummer body on it) had a Banks kit on it with the standard Banks OCG filter in it. I also saw dust in the intake. Now the BUM-V literally lived in the dirt so that was a rough environment, but I wasn't going to sand blast my engine to death. I found a used filter housing from a 600 ci turbo diesel tractor that used a huge polyester media filter that was like 20 inches long and 10 inches in diameter. Per square inch of media, it was was way more restrictive than the OCG but it had about 20 times more media. Though it was a replaceable element (about $110!) it was also cleanable with soap and water. Problem solved and I ran that filter several years, never cleaned it a (though I dumped the trap at the cyclonic unit a couple times) the restriction never indicated above zero.

Excessive dirt could also be from a defective or poorly cleaned filter. Defective is one thing but cleaning is an important topic. OCG filters are fragile to poor cleaning. Water pressure or compressed air blasts the fibers out of place and leaves holes. I have a SWRI test of OCG filters that shows how you can lose 25% efficiency by improper cleaning of OCG filters but its also showed that even when you cleaned one properly, you lost a couple percent when you did. Efficiency is only about 50% if you don't oil it properly.

And people clean their OCG filters way to often. Remember when I said above that filter increase efficiency as they load up? OCG especially! They literally have to be caked with dirt a quarter inch deep before airflow is negatively effected and that "cake" (and this is the official term for it) actually becomes part of the media and helps to improve efficiency. So let 'em get good and dirty before cleaning. Better yet, install a filter restriction gauge and don't touch it until the gauge indicates it's time. That way, you can benefit from the increase in efficiency without a cost in power and you aren't risking the filter by cleaning excessively.

If you have an OCG filter, the quick way to increase efficiency is to run an oiled foam sock on top of the element. You can pull that off and clean it as often as your "air filter insecurity" ( <: < ) dictates! It take some mental readjustment to go strictly by the filter restriction gauge. ANY TYPE OF FILTER IS BEST LEFT ALONE UNTIL IT'S TIME TO CLEAN OR REPLACE as indicated by restriction. You can mung up the sealing aspects of an air filter by R&R-ing it too much for inspections.

I am not pulling any of this out of my ass, either. I have written extensively on air filtration and had the honor of talking with the people who design and build air filters. I will be starting on another story soon and will be getting a refresher course on this. One of the major filter mfrs test labs is nearby and I will go in there again.

To learn more and for pics go here: http://www.trailerlife.com/rv-trailer-news/the-truth-about-engine-air-filtration/

What filters do I like? Anything stock or replacement with a lofted "synthetic" media is good (the fuzzy looking ones) for both efficiency and airflow. I really like the AEM dry media. It starts out nearly 100 % efficient but is cleanable and not particularly fragile. Airflow is average but better than a cheap paper filter. For myself, I will sacrifice a few upper end hp to avoid ingesting dirt.
 
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marmot

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Jim, thank you that is some great info. I ran a K and N for 10 years on my fj60 and cleaned and oiled it twice. Never had a problem. I am religious about using wix filters for my 7.3 psd every 9k for the last 200k and I will keep up the tradition with this new IDI, I have a freshy in the air box right now. I really think it is essential for longevity to keep good clean unrestricted air flow in these diesel motors.
 

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