http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

What an interesting and worthwhile look at what is perhaps the motors worst air restriction. (The next article I will try look at exhaust, another HOT topic.) Recent calculations reveal that the stock D-max consumes 600-900 cfm of air at full throttle, using a reasonable VE of .8 (hope that is good). I was just messing around, and read this, and read into it some more. I found it interesting that airflow tests for restrictions were done only up to 350 CFM. And that's fine and dandy a pretty average flow expectation. But now we're talking "how does it perform at full throttle, with a mod or 2".


http://dieselplace.com/forum/attachment.php?attachmentid=292&stc=1

This may seem innocuous, yuh, so, what's up? Well I like good filtration, and clean oil etc etc like everyone else. I look at this graph, and knowing a little about fluids, I see an extrapolated 10-20" of water drop. Goes to understand now why the uni's and K&N's have some performance advantage, albeit lousy comparitive filtration. (funniest thing I ever heard was a post where someone suggested using by-pass air filtration!)

Now let's dirty it up a bit (yeah that's a clean filter in that chart)

This is how time (dirt actually) affects the same properties at only 350 cfm, albeit extreme loading in the lab. Holy cow patty batman. Won't be passing anybody today. I love to play with numbers, that's coming.

I saw 0 gain in et at the track(same day) from swapping out my stock ac delco paper for a AFE stage 2(non progaurd) air filter. Also talking to Steve Cole when he was playing with the transgo truck people we giving him **** over running a filthy stock paper filter in the factory box, he removed it and ran the same time. Dont think I have heard of anyone coming up with much if any gain even on the dyno.

The turbo is the biggest limitation for getting air through the motor. JMO

Edit: I will say though that this is interesting and may bring up some very good disscusion:)

...and now I see your point, even 20" of water is only .7 psi (.7 psi the turbo has to generate to overcome it).

I duno how the calculations work in but I'm just relating what I have seen in the real world. .72 psi isnt much or it may be alot in relation to things??? I duno but to the D max it dosnt seem to bother it from what I have seen.

Were you thinking of trying to come up with a less restrictive air filter/intake set up?

Were you thinking of trying to come up with a less restrictive air filter/intake set up?
Reading my mind?

At first I thought using a dual filter mod would be a benefit. Now I see the truth.

.7 psi is .7/30 times 900cfm, or around 20 cfm. A 2% gain potential, not measurable in et's or 1/4 times I'd guess. So a dual filter design might get you 10 cfm back. Not worth MY time. The guy who uses dirt roads at 120 mph every day might appreciate it...until he dies that is.

Short thread this time.

FWIW, gotta hate that amsoil filter (green). The AC delco really stands out as the longest lasting for the dirt roads. Almost linear loading curve, what capacity!

Ram (cold) air would be more useful, maybe.

Those results do show that they missed the mark in testing, the first test should have been flowed to around 800 cfm (just because the restriction numbers in the 350 cfm area are so insignificant to vehicle performance). At first, it's very impressive looking. If that chart were scaled to reality, say, vertical axis of 100 " of water, then all of these filters would combine to look almost like one line. The differences between filters in that graph are "insignificant".

The filtration efficiency, on the other hand, tells a different story.

I don't know who built these charts, but its deceptiveness really bugs me. As a first glance visual too, it makes it look like the KN doesn't filter anything.

it catches birds and small chipmonks :D

That's enough for me! I got 50G tied into this truck and the last thing I want is extra dirt getting into the engine. How much is too much? ANYTHING more than stock is too much. Bye bye K&N!!!!!!!!! It's in the bargain finder now. (after 100 miles and a costly lesson):mad:

I don't know who built these charts, but its deceptiveness really bugs me. As a first glance visual too, it makes it look like the KN doesn't filter anything.
I built the chart and I can assure you that it wasn't my intent to be deceptive. The scale is linear and it shows the relative differences between the filters tested. One also has to look at ALL the data in the context of the report to see the pros and cons of each filter tested.

:)

Bill

I probably used crude language, always got my foot in my mouth. Let me apologize, and say, like many others have said, excellent work! Picking apart the details of charts, not what I set out to do, and obviously there is no intent to slant the results. That's the job of the manufacturer as we all see occasionally. The 2 best at particle efficency, AC and Baldwin: AC could use your data to say: "The nearest competitor allows 4 times more dirt in". Kind of like skim milk, "99% fat free" when whole milk is already 96% fat free.

Thanks again, it is one of the best studies I've ever seen on a subject like this.:ro) I hope you did see my point. Absolutely did not mean to insult.

Can you tell me if the 350 cfm was arbitrary or was there some reason?

here's what im wondering about - its obvious that more air will have an advantage, albeit a small one, and that better cleaning and filtration is advantagous to the longevity, BUT, have any studies been done on oil analysis at say, 5k, 7.5k, 10k, intervals, comparing the AC Delco and K&N ? id be interested in seeing what that analysis showed and if it showed that it is actually a problem or just a case of, "yeah, it flows more dirt". I mean if the end result isnt over whelming in terms of it being far superior one way or the other, than its a moot point ? im not being biased either way, as i have used 2 different air intake set ups and different filters and have always gone back to the stock paper element which i currently run. Im just thinking aloud here and wondering about the end results and supporting tests that would really wrap this whole thing up for us all in regards to the TOTAL ANSWER, if there is one ?

I don't know of any, but something similar is certain to be floating about. I have heard of people ruining motors by running without a filter, but don't really know if it has anything ultimately to do with oil contamination.

Search the air filter companies, you'll find something they have manipulated.

i dont want manipulated numbers, i want real world test info !!! isnt that really the bottom line to all of this ? the air filter test shows us good information but lets go beyond that and figure out if it really means anything ?

isnt that really the bottom line to all of this ? For me, the study here shows the bottom line, answers every question I would want answered (save for the 800 cfm flow pressure drop) The AC has the best filtration, holds the most dirt (not just a little, 3x more), and at the end of its useful life (2nd chart), still has less pressure drop than any of the others. Nothing else can really matter to me.

Add to this I don't have to oil anything. Sold.

yeah, but what about those of us who would prefer to change oil more frequently, and either clean or replace an air filter ? I tow my toy hauler all the time so changing oil, even synthetic at 5k is nothing to me, and i would rather replace the air filter every 5k as well - maybe thats a bit much but id rather be safe than sorry, and the oil changes dont cost a whole lot and i can get air filters of any kind pretty cheap, so its a cheap price to pay for peace of mind. Maybe im alone on this one, and again, just trying to figure out if all that information means anything other than the obvious ? maybe ill have to do some testing on oil analysis if i cant find anything. anyone else have some information on this ?

I would add, based on what I read into your statement: Air filters don't wear out, they just load up, and as they do, they filter better. So if you discard a filter that is still flowing adequately for your air demands, you just reduced filtration efficiency. (man, I am going to get flamed now)

Though I do think at some point, the system starts sucking particles through if it gets really loaded.

But that doesn't happen. The AC Delco holds over A POUND of dirt and still has nil pressure drop. I believe that because my 100 sq ft pool cartrige filters (I have 4 of them) will hold over 10 pounds of debris each, and the gauge still shows nearly no pressure drop, wonderful flow. Get some high pressure air and blow it back the way it came, I see no reason for discarding it.

As for syn oil, 5K is overkill for most (after first 3,000 miles break-in), I read all day that oil samples on syn can go on for 20-50K, before testing shows a contamination requirement to change, or breakdown of viscosity. We are a wasteful society for sure, letting oil companies run our bank accounts (rant). With bypass oil filtration, some OTR guys send in a sample (when they change the factory filter only) and run it until the sample comes back "change". Most of the time that is over 30K. If I remember, silicon, is usually the reason. Supposedly comes through the air filter over time, but who knows for sure.

But it goes against what our daddy taught us. Oh well.

So what I would say, is this. If you are trying to go from 20K to 40 K on oil changes, have the best air filter you can get, and keep it unloaded. But if you are worried about 5K on syn, I'd say get some sleeping pills with the money instead. If you are a desert Baja racer, or one of these LLY overheat situations, these are special cases.

lets see, i dont need sleeping pills - LOL, and i dont change it that often, was just thinking aloud. I change out at 7,500 on synthetic only because i tow over 35% of my miles, and i go into the desert once a month , and am in dirt, mud, sand the other 2-3 weekends as well, so i would just rather play it safe in regards to changing the oil. Thanks again for your input, it totally makes sense and i appreciate your thoughts on this

Nobody told me the discussion moved over here! I will try to answer a few questions. Masterp2, the 350 cfm used in the test is not entirely arbitrary. According to the ISO 5011 test standard, there is a suggested flow rate. IIRC from what Ken told me, this flow is something like 60% of the max flow for the filters application. So if 350 cfm is 60% of the max flow for the Dmax, it jives. Because Ken had data from Fram, he used the flow that Fram used when testing their filters for the Dmax. Certainly the dirt passing a filter and the filter's efficiency is affected by flow. Most filters probably pass more dirt at higher flow rates. But as long as ALL are tested under identical flow rates, all is good. I doubt the filters would stack up differently at a higher or lesser flow rate.
tbone1227, As far as a study on comparing oil analysis from different air filters, I doubt it has been done. The problem is that the dirt in your oil is a result of air filter efficiency AND the air quality you drive in. A K&N may show great oil analysis if the vehicle is driven in clean air. A paper filter may show high silicon if driven in a windy desert. The only way to do it is run multiple vehicles simultaneously under the identical conditions. Hard to do in the field, need laboratory control of variables. SPICER

Thanks Spicer, as I said before, and as you have probably heard a million times, nice job.

I wonder if anyone has a definitive answer to the stock D-max max air flow rate, WOT, I have estimated it at 800 cfm. It would good to nail down for the water/ alcohol injection scheduling I am doing.

These charts are done by a SAE certified test facility like my company operates in Kearney Neb. I am a Baldwin DSM. These charts show that the worst air filter has a "Start Up Efficency of at least 99.00 %. This is the minimum that any engine manufacturer will accept. The Baldwin minimum is usually 99.91% or better. We have satisfactory air flow and at least match the OEM which is ACDelco. Our goal is to stop at least 99.91% of all dirt and provide adequate air flow as per the OEM specs provided by a OEM.
If you dust a motor and the OEM finds the aftermarket product caused the problem the OEM is not obligated to pay for warrantee. Read the Magnusson Moss Warrantee Act, 15 U.S.C. SS2301-2312 (1982) sometime.

Hope this is informative.
Jim Baird
jrbaird1@earthlink.net

Lets see if I understand this correctly.

This chart is telling me my K&N has a less than 4% difference in filtering ability than my stock AC filter?
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http://dieselplace.com/forum/attachment.php?attachmentid=295&stc=1



And here it shows the AC filter has twice the resistance to flow than my K&N filter?

http://dieselplace.com/forum/attachment.php?attachmentid=292&stc=1


For less than 4% I call it a wash and not worth arguing about.

looking at that chart, the restriction is in water:eek:, I hope I don't start sucking water into my intake.):h

I dont know much about filters but what are you saying for dumb people like me? Is it worth buying an aftermarket filter and which one? And what does water have to do with air filters? And what is safest for the motor?

Has anyone else noticed Masterp2 disappered or is it just me?

Been a looooooooooong time since hes been around

baimpala is a MIA also

I think that Masterp2 got the boot and baimpala I think is on patrol.

I haven't PM'ed him, (baimpala), but he was in between boats and was waiting for a new ride. If he's on a boomer, he won't be back for a few weeks.

He may be on special assignment that is not allowing him to stay in touch.

masterp2 got a little frustrated with the site, pretty much just said see ya. do not think he was booted........ ??