First post of this thread has been updated to include a pdf of the results (thus far) for this testing.
I'll throw them in here as well. Screenshot below and file attached as well.
Link to first post. https://www.ford-trucks.com/forums/1...l#post19379859

Further plans:
1) Test AIS without filter
2) Tow results with AIS
3) Possibly retest the 6637 with gauge in end of filter (simulate FM location out of airflow).

 

Performed the AIS no filter test today. 65° in the afternoon.
The results would seem to indicate there is some restriction within the AIS plumbing itself as vacuum was up from 6637 testing.
Overall it was much improved versus the AIS with filter which is no surprise.

It appears there is a 0.2inHg restriction within the plumbing of the AIS (no filter) versus the 6637 with filter.

I have updated the pdf to show the new results.
Something to note, I have also modified some of my previous results within the file as reviewing the videos looks like I had some numbers off just a bit.

I'm also noticing that it seems there is a difference in vacuum readings between a WOT run and a constant boost condition at the same boost level. I assume due to the sudden demand for airflow and rapid increase of flow.
I still believe a big part of the vacuum we are seeing above 25psi is due to the CCV port location and venturi effect.

 

Well something has changed since my last update. Hopefully it doesn't effect the testing results too drastically. I have removed the S364.5/large turbine and replaced with a S363/small turbine.
Towing with the the 363 and AIS showed no smoke in the 65hp tow tune.

Updated test results to include towing with the AIS. This includes both the CCV & FM locations. Towing was in PHP 65hp tow tune.
What I am finding is the AIS can keep up fairly well as long as you are not pushing it to accelerate quickly in a high HP tune.
The FM only pulled to 75% on the entire 3 hour trip to the track....which included a few rowdy throttle bursts (not full throttle though) along the way. I find this acceptable for my usage of the truck and prefer the quiet filter to the noisier 6637. But as you know I will likely get PMS and put the 6637 back on in the future.

This concludes my current plan for testing, however I would also like to check a few more things so who knows there may be a couple more updates before I pull the vacuum gauge from the truck.
One I really wan to try is the AIS without filter with the gauge in the FM location. This should tell us if the box itself is a restriction. I already ran this trial but that was in the CCV location and the high flow of air seems to create vacuum above 25psi. Imagine that, the CCV hood performs well at canceling the venturi effect up to the point the factory PCM will de-fuel....and this also seems to be the limit of where the AIS will start to become a restriction. Almost like they designed it to meet a target...

Updated file is attached and first post has also been updated.

 

Great work Jason. This may prove to be valuable information for someone and your verified and actual numbers are revealing.

I can only imagine how quiet your SXE is with the AIS intake... Perhaps if there is a Meet & Greet in your area, Kate and I may be able to make the trip up.

 

Or yell at me next time you’re up I-77 in WV. I’d love to catch up with you, drink a coffee, and shake hands.

 

Great thread Jason! I finally got around to reading the saga. Reps sent!

Now do it all again with a sleeved AIS!

 

Thanks for the kind words.

I have considered it. But then I get to wondering if the design of the box is such to help the direction or swirl of airflow as it enters. If you look at how the box is shaped, it has a rounded design. It appears as the air comes in from the snorkel that it will smoothly flow around the box. I wonder if the fender sleeve mod could actually interfere with this smooth flow? @Y2KW57 thoughts?

I believe my next step is to check the box/snorkel resistance by testing in the FM location with no air filter. If the vacuum gauge doesn’t move then the box is not the choke point. I estimate it will move but not by much.

 

Ford, within the teething pain period of the very first year of 99 up Super Duty production, eliminated the fender well inlet. That alone would give me second thoughts.

How does air get into the fender?

Take a baseball card, or a Pokemon card out of the sleeve, and cut it in half. Diagonally. The scalene right triangle that remains is about the size of the admission orifice that allows air into the fender, and that orifice is at the bottom of the wheel well arch, at the drip edge of the truck... the last point of contact that snow melting off of the truck encounters before separating from the truck on the way to the ground. Only it is freezing, so it doesn't quite make it to the ground. Instead, it forms an icicle. which builds in girth and length like a stalactite in a cave.







Images presented in the public domain as found on search engines, displayed here under the Fair Use doctrine for educational purposes to illustrate formation of mud and ice stalactites at the forward end of the front wheel well, where the triangular orifice that admits air into the fender on a 99+ Ford Super Duty is located.

An earlier thread on topic of adding fender sleeve into AIS:

Revisiting AIS airflow rates

The only way that I would cut a hole into the side of an AIS box and foam sleeve an enclosed conduit between the molested box and the Ford abandoned oval hole in the inner fender wall is if I cut a corresponding size hole into the outer skin of the fender, not in direct line with the inner fender hole, but aft of it, where the fender emblem is located.

I'd probably cut the hole the same size and shape of the 2008-2010 outerskin fender emblem opening, where a combination emblem and vent is located on the newer trucks.

I'd have a custom billet gridded vent that would be a working vent for the entire area of the factory combination emblem vent, substituting more vent in lieu of the upper half emblem badging.

I'd then temporarily remove the under fender liner for access to construct a water baffle designed to redirect water down from the vent, while admitting air to the upper portion of the fender.

I'd block foam the uppermost, rear most area of the fender near the driver's side hood hinge, to excommunicate under hood heated air from the well of ambient fender air being fed by the new hole I cut into the exterior sheet metal of the fender.

I'd drill larger water drainage provisions at the bottom rear of the fender, where the fender meets the rockers and leading edge of the driver's door.

All sheetmetal cuts would have to be sanded, H3PO treated, self-etch primed, fill primed, painted, and clear coated.

If going for fender air, why fuss around?

Otherwise, just putting a shop vac foam sleeve inbetween the airbox and the existing fender isn't worth the effort to me, and can be undermined easily by caked up mud or iced up snow at the lower triangular orifice at the bottom front of the wheel well.

Since I'm not going to go through all that bother above cutting a hole in the outerskin of the sheetmetal fender to make a genuine fender inlet similar to what can be found on Hino, Freightliner M2-106, GMC TopKick / Kodiak, International MV series, and too many other medium duty diesel trucks to mention, my thoughts are to leave the AIS as it was originally designed by the team of engineers who put a lot of time into it. I had the chance to meet one of them. He explained quite a bit to me about the previous air box (production) evolution. He was stationed by Ford as a production engineer at KTP, but strangely, he made it his personal mission to resolve. in incremental iterations, the issues of the production air boxes that the earliest Super Duties had. The AIS finally presented a satisfactory solution to a lot of those early issues.

 

Tryna think it thru. The design of the AIS intake starts at the top. Top is rounded rather than squared to flow with less turbulence to the intake tube. Rounded top dictates shape of filter, filter dictates shape of lower box. Part of the function of the lower box is just to be a larger volume, lowering air pressure and speed coming from the snorkel. That allows heavier solids to drop out before getting sucked into the filter media. The idea of sleeving is to allow additional air entry at the end of the lower box so the AIS snorkel is no longer the sole source of air. Air coming in from the sleeve does plow right into the side of the filter media, which is not ideal either from an air flow perspective or for potential water intrusion. The original flow design is not altered, except at the end nearest the fender, furthest from both AIS snorkel and intake tube. I don't see that as an impediment but who knows? Having more sources of air in front of the filter, especially furthest from the intakes, seems like a good thing.

Plenty of good reasons why sourcing air from the fender well was a bad idea and smart that Ford abandoned it. Thank you for posting up that info again Y2K! But adding air from there as a contributor? Obviously I'm spitballing all this, but it makes sense to me.

It also makes sense to me the vast bulk of restriction could be simply due to the design and size of the filter and adding air sources before it makes no difference. All them little tubes passing off air to each other is great for filtration but looks like crap for air flow. If a filter twice as large could be fitted maybe we could solve the problem.

Or try a pull with no lower box at all? Way more apples to apples with a 6637.

Duct tape.

 

Y2KW57 thank you for sharing the information again and the link. The link, and some subsequent ones, had a lot of information in them. Tugly stated long ago that going above 30psi (I think he said) was about the limit of the AIS. His opinion seems about right. What I have been seeing is crossing the 25psi threshold seems to start getting out of the AIS design parameters. Which coincidentally is where the factory PCM will defuel. So I think your guy at Ford did a great job designing this thing for what the truck was supposed to see.

The main reason for tagging you in the last post was because I was interested in your opinion on how the fender hole might effect airflow within the box. Do you think the right angle air entry would negatively impact the way the filter is getting its air from the snorkel? The shape of the box and radius from the snorkel area almost looks like it was designed to make it swirl around the box as it gets pulled into the filter. Maybe this is for more even distribution through the media? Or maybe it is to help the flow?

aawlberninf350, you may be right. Possibly the only reason it is round is because it was designed top down. I'm still curious how the fender mod will impact the air flow, not the rate but the way it flows. Will it cause extra turbulence? Or like you said, will it just better supply the opposing side with more air and no adverse effects (besides the possible water intrusion)?

 

Here are some pics of my AIS filter some time ago, after about 35k of use. Front, back, and the end where sleeve is located. The dirt gives an idea where the air is flowing. Looks like the sleeve end definitely sucks in some air. Small cut there is from flash I failed to remove when I cut the hole. Thinking the extra dirt on back might indicate some turbulence. Really not scientific analysis, obviously.

The filter was upside down so to recreate the 'in service' position I flipped the pics over. That's why the text on the filter looks crazy.


Front

Back

End

 

Like most automotive products, the AIS was computer aided designed, but with the distinct advantage of input data already established by the existing envelope within which it had to fit.

I had a couple of photos of the prototype in white (it was literally an all 3D printed mold) in off road field testing, but that was several laptops ago, running Windows98 (upgraded from W95).

Maximizing dirt holding capacity, and prolonging the service interval, were the strongly stated goals that were emphasized to me.

Believe it or not, some Ford employees were very enthusiastic about their jobs, and their enthusiasm was infectious in a positive way.

I met a guy at KTP who was responsible for having the frame labels changed from black letters on a white background, to white letters on a black background. He drug me around to look at front wheel wells and exclaimed, "Look, see how much better that looks without an ugly white label visible in front of the tire?!?" I had to agree with him, the black background label did disappear against the black wax coated frame much better than the white label, but what I really was impressed with was the guy's pure enthusiasm for his role in motivating the production change. That moment actually left an indelible impression on me. The enthusiasm that individuals contribute to an organization, where no specific reward or return is promised to the individual for that effort, is priceless beyond the salary and benefits that the organization pays that individual.

Anyway, that same type of enthusiasm existed with the air box / air filter for the 00 and up Super Duties, both within and outside of Ford. I corresponded with the Wix engineer whose work resulted in the FA-1750, which at the time was the ultimate production air filter. But years later, I've seen what FRAM's top of the line 1750 substitute looks like, and I was duly impressed. In the performance aftermarket, Volant hit it out of the park with their first airbox, which came out before the AFE II or 7 or whatever it was at the time. I tested the Volant on a flow bench, and it rocked well over 800 cfm at 25" water column restriction. Look at S&B. They had a box already, but no, they revisited the application once again, and came out with a second box. So lots of "enthusiasm" from all types of people, some stakeholders, and some with nothing personal at stake but a better running truck, have been devoted to the very same questions that your testing seeks address.

But back to the AIS design. With ease of serviceability being the goal, all the available space was utilized while maintaining clearances with neighboring components within a specified spherical zone, so as to fit the largest clean sheet Power Core filter element possible, which again was specially designed and framed for the application, including contemplating what if the media becomes saturated from road mist on the dirty side and crankcase vapors on the clean side, and how shall the media be structurally reinforced to prevent weakened, saturated media from being sucked up into the turbo. So that rigid plastic frame with ribs bridged over the ends to provide gusseting with the least possible flow interference is part of the enthusiastic engineering that we pay for with the price of the filter.

Another feature in serviceability is that the airbox lid is designed to be removed without having to unscrew the worm gear clamp of the inlet duct. After the four clips are released, there is just enough room to lift the lid, and then push the lid inboard toward the center of the engine while still attached to the intake accordion like tube, thereby compressing the flexible intake accordion a bit in order to clear the fender lip flange, and raise the still attached lid up. These lid lifting actions were actually tested by engineering, as the engineer demonstrated for me for with the production lid design.

The depth of the AIS filter is constrained in part to maintain the ability to dive the outboard (narrowed end) structural plastic and EPDM sealed surround all the way underneath the fender flange lip and over the air box bowl seat, at an angle such that the depth of the media just clears the inboard edge of the air box bowl, before settling the filter down into it's home position. If the media was any deeper, than damage to the media might result in the mere act of servicing it, and the goal is ease of service.

Speaking of damage to the media, the two supporting ribs that jut upward from the bottom slope of the air box bowl are as thin as possible to block the least amount of holes in the media, but they are also angled (in a slight arch) so at to cross multiple rows holes at a diagonal, to distribute support in the center of the media, instead of concentrating the support on only a single "row" of holes. The pre assembled media can be likened to a long strip of corrugated cardboard wrapped upon itself, and the center of the wrap is the straightest. The curved arch of the two bottom ribs (ironically, stalagmite like instead of stalactites) crosses several of these central rows distributing any accumulated filter weight gained from trapping dirt.

Now, as to why these bottom ribs are arched, instead of flat diagonals, enters into your persistent pondering about the internal micro aerodynamics inside the air box, which you are concerned that boring a hole in the side of the air box might disturb. I think your concerns are valid, and there are observations to be made about the box (dirty side) that speak to the effort to best manage the entrance of air into the filter. The idea of top lid down design is irrelevant. Once air has passed through the media restriction and has entered the clean side of the airbox, which is the top lid, we don't really care about what happens to the air past the point of restriction, in terms of weighing the neutrality or detriment of cutting a hole on the unfiltered dirty side of the box.

With the lid being thus irrelevant, let us then focus on the shape of the bowl of the air box, that being the very bottom.

Take a look at the HVAC ducting of any given building, whether it be the attic or basement of a house, or between the roof trusses of an industrial building, or above the unfilled drop ceiling of a chic retail store or restaurant. There is a graduated, calculated, reduction in plenum size the further any given trunk of ducting extends from the blower fed source supplying the conditioned air. Nearest to the supply, the duct diameters are large and expansive, and furthest away from the supply, the duct diameters are smaller and constrictive. There is a science to this graduated constriction of diameter over distance. People get graduate degrees in calculating flow, volume and pressure.

But for our observation we don't need a degree. We can easily associate the HVAC parallel with the sloped floor of the bowl of the air box being deeper at the inboard snorkle entrance side, which is like the larger diameter HVAC plenums nearest the blower, affording more room between the airbox floor and the bottom of the filter. Likewise, we find the floor slope ramps upwards in the outboard direction toward fender side, becoming shallower, affording less space between the air box floor and the bottom of the filter, much like the smaller diameter HVAC plenums furthest away from the blower source.

The Power Core filter media has 50% of it's channels open at the bottom of the media block, evenly distributed over the entire surface area of the block. To most efficiently employ the vertical surface area of each channel equally in the work of filtering the air, the bottom surface of the air box is ramped, like an HVAC plenum trunk is graduated, so that there is an even division of labor (or an even rate of flow) distributed through all channels simultaneously, even though some channels are nearer to the source of air (the snorkle) than others.

If the HVAC trunk plenum was all the same diameter, then the HVAC tributary registers nearest to the source of the conditioned air might deliver more of it than the registers furthest away from the source. In a similar manner, if the floor of the air box were flat, then the channels nearest the source of air might end up doing more "work" than the channels furthest away from the source of air. The optimum utilization of the Power Core filter is for each individual channel to be fed equal amounts of air to filter simultaneously, to present the least amount of net restriction to total flow. The more surface area, the more filtration, the less restriction per instant of time to achieve that filtration.

So I would agree with you... it stands to reason that there is some design effort inherent in the shape of the dirty side of the airbox, and that the ramping of the floor is by design to promote the full and simultaneous utilization of all the channels in the Power Core media to achieve the most filtration at the highest flow rate with the least restriction. Similarly, it stands to reason that curve radius of the central media supports jutting up from the ramped air box floor are also not by accident.

Likewise, it is not by accident that I wandered off topic on a seemingly unrelated tangent talking about the enthusiasm of the Ford KTP employee who spearheaded a campaign to change the background frame label color. That was to illustrate that there are people behind these products. People with enthusiasm. People with passion. People with brains. They are not blind, and most are definitely not stupid. If there was a meaningful benefit to taking advantage of the hole that is already there in the inner fender stamping, that opportunity would not have escaped their notice in the design of a non-production, customer pay, 100% optional air box designed solely for this and no other possible application. They are enthusiasts too.

These are just my observations and thoughts, which was what you asked for. They are only offered in response to your questions now twice directed and tagged to me, and are not in any way intended to refute the findings or feelings of any other enthusiasts on this forum who cut holes into the side of their AIS.

In the attempt to quantify a difference should you decide to cut the hole, your currently published data set reveals a two month and 20° ambient temperature differential spanning between summer and fall. The temperature and humidity differences can be more meaningful in measurement than the hole. But that depends on what you are measuring. Boost? Or Power?

I see videos on YouTube where the driver smashes the accelerator pedal and the boost needle sweeps the dial all the way over to the other side...45 pounds of boost. But I'm not watching the boost gauge in the video that intently. I'm more focused on what can be seen through the windshield of the truck in the video. I'm looking at lane marker lines, observing the rate at which they intersect a fixed point like the A pillar. Or I'm looking at the speedometer, if the speedometer is visible in the video (it often isn't, because the video maker has the camera trained on the boost gauge, which is what is important to them.) So I see the boost gauge sweep to 45 and holding, and the engine sounds a lot louder, but the truck isn't going much faster. All sound and fury, but not fast and furious.

There are some notable exceptions to this. A month or two ago I watched some videos posted by @Peixinho for the first time, and I've never seen a Super Duty truck driven so fast on public roads. He showed the speedometer in his videos, and the speedometer was pegged. It hit 100 mph, and the lane lines kept zipping by even faster. Were he to have been caught, the judge would probably send him to flight school instead of traffic school. After he served a jail sentence. So in that case, I observed a performance difference. Not one that I'm interested in personally, but it was observable. On the other hand, some videos I've seen with sky high boost, didn't translate to observable performance.

Some recent videos that I really liked happened to be yours @RacinJasonWV . I'm actually quite a bit envious at how smooth your engine purrs under load with your 363. Your boost to back pressure ratios are enviable as well. Makes my engine sound like a bucket of bolts being tumbled in a cement mixer. It must feel amazing for you, to have come from the frustration you were feeling a few months ago, to the freight train that you are pulling with now. Congratulations on your perseverance in finding the right combination that suits your need.

Which returns us once again to your testing, and decision about what to do about your air filtration solution. Testing from sample to sample has to be in similar ambient conditions to derive more meaningful observations about differences in what is being tested, as separate from differences in the environment tested in. Likewise, as said before, a gauge resolution that better matches the range you are measuring will also yield more confidence inspiring data to distinguish differences.

Finally, it is commonly said that boost can be viewed as an indication of restriction, and restriction is an indication of load on the engine, which the rotating assembly incurs pumping losses to overcome. So the question then becomes, are the 2 additional pounds of boost that you seek by adding the hole in the AIS, going to actually contribute an increase in oxygen content in the form of air density, and will that contribution be greater than the cost in restriction and the pumping losses incurred to overcome it, so that there is a net benefit from the additional work?

 

We are so lucky to have contributors here who had boots on the ground! Writing down the history of how it happened so we can peek in. Thanks for all you do Y2K!

Got me inspired to go out and see what's going on with the AIS currently. Same filter as above, have not paid any attention to it for a couple years. Filter minder idiot light never tripped and MPGs did change so... yeah.

Scrupulous Maintenance!

Did find some corrosion on a battery terminal so I'm glad I was under the hood.

So front, side, and back of filter.


Front


End


Overall it looks dirtier than a few years ago, but in a nicely diffuse way, no super dirty zones to indicate concentrated air flow. Then I tapped out the filter to clean it. First tap had a fair drop of solids. Maybe a bit more solids from the sleeve end, but that could easily be caused by the uncontrolled specific mechanics of how I dropped it.


Then I tapped it our a bunch of times, check out the load it was carrying!



And a shot of the bottom showing the marks from the support tabs Y2K described.


Yesterday I had a few hours on the highway and gave it WOT times in the 120 tune. A bit of black smoke at first tip in, as usual. Also one good grade where I could slow down and then hold WOT for a good 45 seconds. Today found the filter minder sucked in only 25%, even with a dirty filter. On stock sticks, stock turbo with billet wheel and tunes to match the filter flows fine.

 

Thanks for the awesome responses gentlemen! I read through them but unfortunately don’t have the time right now to give good enough replies in respect to your detailed posts.

I will throw out a teaser though. Today I tested the AIS box without a filter with the gauge installed in the FM location. The box itself is definitely, without a doubt, a source of restriction. Now, I still need to watch the videos more and dig in a little deeper. It may be possible the box restriction does not add to the restriction within the filter itself if that’s even possible.
The box alone pulled about 0.6inHg above 25psi. This would indicate the sleeve may actually be beneficial. This is just preliminary data though. Let me look at it better before calling it.

A quick response to Y2K’s question regarding boost/power. I don’t care so much what the box does to my “boost” level, at least not directly. It’s more about how much of a restriction is the AIS causing in the system. Too much restriction could cause excessive EGT, less power, or poor mpg. Thing is I don’t try to get good mph over 25psi so.....

Oh I have so much I’d like to say if it wasn’t time to wrap it up and recharge myself. Work comes early in the morning whether I’m ready or not.

Thanks again for the great comments!

 

Thanks for touching base when time was short! Me and Y2K are retired and can allocate time much more readily than a working stiff.

This is *your* thread, update whenever you wish.

But please keep paying taxes so we can buy yachts n chit.