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@aawlberninf350 David, great information and participation in a discussion as usual! The visual aid of dirt on the AIS filter are key to this discussion in my humble opinion.
I tried to rep you, but am in jail.
Jason, your work here is not unnoticed, clearly. Thank you for your time and effort in order to educate the us on some of the questions that have been on this social platform for quite a long time.
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.
No problem. I have quite a few years left to support your yachts. Enjoy it, you earned them!
Originally Posted by Sous
David, great information and participation in a discussion as usual! The visual aid of dirt on the AIS filter are key to this discussion in my humble opinion.
I tried to rep you, but am in jail.
Jason, your work here is not unnoticed, clearly. Thank you for your time and effort in order to educate the us on some of the questions that have been on this social platform for quite a long time.
Yes I have enjoyed his contributions to the thread. Now if I could just get him to run some tests (with a better gauge) and validate my data.....
Awesome write up... the PDF charts really make it easy to follow.
I have not had time to completely read everything... been trying to skim through during breaks.
I do have one question or maybe I should say a thought... It would be cool to see the performance difference between each filter BRAND NEW vs READY TO CHANGE. To see how the data changes as the filter starts to clog up.
Would also be cool to do the same tests with a slightly bigger setup pushing 35-40psi of boost to see how much vacuum increases.
Coming from the standpoint of someone that diags turbo issues all the time... I have had many customers eliminate turbo problems by getting rid of the 6637 filter and change over to a higher flowing filter. I have seen it cure turbo surge, turbo bark, high egts, intake boots sucking closed on aftermarket filters, etc. I have not been able to narrow it down to any certain "brand" because I know there are a lot of variations of 6637 filters. But we keep a running log if issues customers have had and we have seen the 6637 filter cause enough issues that it is one of the first things we check now when a customer reports a turbo performance issue on a 7.3. But that is not to say the everyone that runs a 6637 filter will have issues because we have many customers running them with no problems.
I know "turbo dusting" and/or "engine dusting" can be a hot topic from "high flowing filters". From our in house testing, customers, and turbo repairs over the years we never see turbo dusting issues from "high flow filters". What we always find is an issue where the turbo is sucking air around the filter or bypassing it. For example flat k&n drop in filters are often taller and when you snap those air filter clips down they often break the plastic and ends up leaving an open gap. Or someone who runs a filter so long it gets a tear in it and sucks dust/sand through. Just food for thought
For example flat k&n drop in filters are often taller and when you snap those air filter clips down they often break the plastic and ends up leaving an open gap.
I don't know how they are made today, but 20 years ago I flow bench tested flat panel K&N and S&B air filters that were drop in replacements to the stock air box for the 99.5 to 03, and I didn't find the perimeter seal profile taller, but I did find the perimeter seal to be made of an elastomeric that had a harder durometer than the OEM flat panel filters, and as such, these seals were less compliant to compression from the latching clips retaining the stock air box lid.
Above: K&N on the left, S&B on the right. (Circa 2001)
Above: Motorcraft FA-1680 on the left (the originally specified filter for 1999-2001) , Motorcraft FA-1750 on the right (Retroactive fitment for 99.5 to end of production. Will not fit early 99 airbox, 2001.5 to 2003 airboxes already optimized for deeper pleat filter with a lower entrance baffle)
The perimeter gasket profile on the Motorcraft filters is as tall, if not taller, but the elastomeric material is also spongier, more compressible, and thus more compliant to lid compression at the latch points, and in the opposing extreme, likewise more expansive along the lid seam where there is no mechanical retention enforcement, which for the OEM box, is the majority of the long edges.
Quite often, the lid not fully seating against the air filter gasket has nothing to do with the gasket material. Take a look at the photos below...
Above: Airbox lid has been clamped down on top of lid alignment guidance tab, more than once. Thus the lid isn't riding high on too tall of an air filter gasket. Rather, it is riding high on the tab.
Here is how the lid was supposed to be seated... Above: Lid fully seated beside the alignment tab, not on top of it. This particular alignment tab is on the firewall side, so it isn't readily visible to folks servicing the air filter.
If anyone is going through the trouble and expense to change to an aftermarket turbo, they by all means should jettison the stock airbox in favor of an airbox that incorporates a filter having a radial seal element.
I don't know how they are made today, but 20 years ago I flow bench tested flat panel K&N and S&B air filters that were drop in replacements to the stock air box for the 99.5 to 03, and I didn't find the perimeter seal profile taller, but I did find the perimeter seal to be made of an elastomeric that had a harder durometer than the OEM flat panel filters, and as such, these seals were less compliant to compression from the latching clips retaining the stock air box lid.
Above: K&N on the left, S&B on the right. (Circa 2001)
Above: Motorcraft FA-1680 on the left (the originally specified filter for 1999-2001) , Motorcraft FA-1750 on the right (Retroactive fitment for 99.5 to end of production. Will not fit early 99 airbox, 2001.5 to 2003 airboxes already optimized for deeper pleat filter with a lower entrance baffle)
The perimeter gasket profile on the Motorcraft filters is as tall, if not taller, but the elastomeric material is also spongier, more compressible, and thus more compliant to lid compression at the latch points, and in the opposing extreme, likewise more expansive along the lid seam where there is no mechanical retention enforcement, which for the OEM box, is the majority of the long edges.
Quite often, the lid not fully seating against the air filter gasket has nothing to do with the gasket material. Take a look at the photos below...
Above: Airbox lid has been clamped down on top of lid alignment guidance tab, more than once. Thus the lid isn't riding high on too tall of an air filter gasket. Rather, it is riding high on the tab.
Here is how the lid was supposed to be seated... Above: Lid fully seated beside the alignment tab, not on top of it. This particular alignment tab is on the firewall side, so it isn't readily visible to folks servicing the air filter.
If anyone is going through the trouble and expense to change to an aftermarket turbo, they by all means should jettison the stock airbox in favor of an airbox that incorporates a filter having a radial seal element.
Thanks for the extensive info... exactly what I was referring to in simpler words.
OK guys, sorry for the long delay in response. I haven't had time to give a response respectful enough for the good posts you guys have added. I will post my current testing status update and hopefully have time to go back and address your posts this evening.
So as most of you probably know by now the turbo has been swapped out since the beginning of this adventure in AIS testing. I went from a 364.5/73/0.91 to a 363/68/0.91. All the testing presented in this post was with the smaller turbo. I reran the AIS test with gauge in FM port with current turbo just for consistency. As Y2KW57 states though, temperature likely has a pretty fair effect on testing. At least in the EGT aspect. The vacuum readings probably remain similar between temperatures.
What I have found is the AIS shows a restriction in the system when accelerating quickly. It seems the rapid call for air outweighs the actual boost numbers. Towing with a steady boost shows a significantly lower vacuum in the air box.
I have also noticed the rpm doesn't seem to play a big factor in the vacuum gauge. This may only be true because the engine is ramping up so quickly that the restriction just holds for the entire sweep. However it is possible the lower steady state towing vacuum is at least partially related to the boost being made at a consistent lower rpm.
As I mentioned the other day, the AIS box has a significant restriction even without a filter. The gauge would hit about 0.7inHg under a heavy throttle. Surprisingly the needle would also move fairly easily even in the 65hp tune during moderate acceleration. This leads me to believe the fender sleeve mod may truly help the air flow of the AIS. I know this has been previously stated by other members based on the FM readings but I was glad to quantify it a bit with a vacuum gauge. The restriction seen from the air box should be from the draw of air through the snorkel. One key point aspect that I cannot quantify (at least not without doing @aawlberninf350 's suggested filter & duct tape method) is how much restriction the AIS filter alone causes. Even though the airbox has a restriction, it may be possible the filter is the biggest bottleneck and therefor we may not actually see any additional restriction from the snorkel. Sorry, don't think I will being adding duct tape to a $70 filter to find out though.
So with this all said, I may be doing a fender sleeve mod to the box for another test run. I know, much to the dismay of Y2KW57. Here's some reasons I'm not overly concerned with the potential ice dam or water aspect. 1) I looked at the fender and it appears a big part of the air would be coming from behind the headlight. 2) I don't drive the truck in the rain or snow much. 3) I'm hoping the twisty turns taken by the air while heading to the box would cause the water to want to drop out. Much like the "Hidden Zoodad" mod Y2KW57 describes in another thread. 4) Many others have ran a sleeved AIS without issue. 5) I feel like this would help the snorkel keep up, especially during those sudden demands for air. I think I have found the correct shop vac filter. Does anyone have a link to a good write-up on a fender sleeve mod?'
What would really be nice is if someone with access to a dyno would perform these tests under more controlled testing and with a more appropriate gauge. @Peixinho would you happen to know anyone with such a facility?
Reading the gauge and various conditions has proven difficult especially when trying to keep the data and readings consistent. For example, I have noticed the vacuum @ 25psi varies between 1st and 2nd gear. I'm assuming this is from the quick drop in demand due to engine rpm and boost reduction. So it would also stand to reason the readings may be different depending on how fast I am travelling when starting the WOT run.
Here are some photos of the different tests. I have also clipped and combined some to hopefully make it easier to compare. I will go back and update the pdf in the original post shortly.
version 1.3 of the AIS testing
Comparison at same mph around max boost for these highway speeds. EGT increase is likely due to weather.
Comparisons at 25psi. Notice the middle ones are different gears.
Awesome write up... the PDF charts really make it easy to follow.
I have not had time to completely read everything... been trying to skim through during breaks.
I do have one question or maybe I should say a thought... It would be cool to see the performance difference between each filter BRAND NEW vs READY TO CHANGE. To see how the data changes as the filter starts to clog up.
Would also be cool to do the same tests with a slightly bigger setup pushing 35-40psi of boost to see how much vacuum increases.
Coming from the standpoint of someone that diags turbo issues all the time... I have had many customers eliminate turbo problems by getting rid of the 6637 filter and change over to a higher flowing filter. I have seen it cure turbo surge, turbo bark, high egts, intake boots sucking closed on aftermarket filters, etc. I have not been able to narrow it down to any certain "brand" because I know there are a lot of variations of 6637 filters. But we keep a running log if issues customers have had and we have seen the 6637 filter cause enough issues that it is one of the first things we check now when a customer reports a turbo performance issue on a 7.3. But that is not to say the everyone that runs a 6637 filter will have issues because we have many customers running them with no problems.
I know "turbo dusting" and/or "engine dusting" can be a hot topic from "high flowing filters". From our in house testing, customers, and turbo repairs over the years we never see turbo dusting issues from "high flow filters". What we always find is an issue where the turbo is sucking air around the filter or bypassing it. For example flat k&n drop in filters are often taller and when you snap those air filter clips down they often break the plastic and ends up leaving an open gap. Or someone who runs a filter so long it gets a tear in it and sucks dust/sand through. Just food for thought
Charlie, I wouldn't waste your time reading through every one of my rambling posts in this thread. What started out as a gee whiz FM check of the AIS progressed into a bit more. But I do wish I had used a proper sized gauge for the job. I just didn't know what range we would be seeing so therefor ended up off base a little. And then I kept expecting to stop this insane test at any moment so wasn't willing to shell out any coin for the right gauge at that point. I'm also about tired of running tests with my PMR truck in the 140hp setting.
Yes, it would be nice to see data with differences in filter used/new conditions but I don't think I would be able to do all that testing. I definitely couldn't do the bigger boost scenarios. lol. I teased you in the other post but seriously this would be some great research for someone with a dyno. I'm just a naturally curious guy who likes data.
Recently a friend of Eswift's was having an issue with loosing boost in a strange way after a turbo install. He sent me the video and it was really odd. The boost would go so far, then drop off suddenly, then return after letting off and getting in it again. They found out the intake tube was collapsing. He told me the guy's tube was a cheap aftermarket one. Just something to keep in mind while trying to figure out why some collapse and some don't.
I personally don't care for oiled filters like K&N. I've had too many issues from dusted MAF sensors in cars over the years. I tried to maintain them but maybe that was part of the issue. I always prefer dry filters.
I have read your thoughts on the 6637 not flowing enough in the past. The vacuum in this testing shows it does flow lots more air. I believe your experiences but can't figure out why it doesn't match what I am seeing in this testing. I have recently tried looking up manufacturer flow ratings for various filters. Those can be a bit difficult to find. But surprisingly the WIX website listed 6637 as the least, then the stock filter, then the AIS as most. I might need to post up some screenshots sometime for a discussion.
Originally Posted by FinnishStroker
Jason,i have been following this thread and you have done huge amount of work with it!
Reps for that! ( i dont know how the rep system works..)
Ok,now i'm going to drop a ball here..
I have resolved an airbox restriction a looong time ago..
And dont gimme that"water intrusion" or "road debris",yada yada...I'm not listening..🙉
It is all good..🤣.......🤔
FinnishStroker, thanks for jumping in here. I always enjoy your comments. If you don't have issues with water intrusion then I doubt anyone will!
Originally Posted by Y2KW57
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.
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.
I checked the slot you were speaking of. It is rather small and is concerning that the water slinging off the tire will be heading it's way. But I also think the water would drop out before getting all the way to the fender sleeve hole. As for damming over, I'm not concerned about that. If that were to occur then the AIS would be pulling air from the snorkel as originally designed. I do understand the concern of this water/ice potentially heading toward the AIS.
Also the slot does not appear to be the only place the fender gets air. There is an opening behind the headlight which I confirmed runs to the fender sleeve area by flashlight method. Overall I feel the sleeve would only be truly called on for air under heavy load. And even then it will be pulling from a few places into the fender. I wonder if it's possible the Ford engineers abandoned the fender source due to issues, but also didn't incorporate it into future applications because of cost. Why put in 2 ports for the airbox if the single source can supply enough air for a stock engine? Now that the snorkel can draw the biggest part of the air maybe the original issues with the fender are not as relevant due to much less air being pulled in from there now. Just some thoughts.
Originally Posted by Y2KW57
Maximizing dirt holding capacity, and prolonging the service interval, were the strongly stated goals that were emphasized to me. I think this may be part of the reason why the base is shaped as it is, to promote even airflow through the filter and longer service life. With my low mileage usage I'm not all that concerned if my change interval is cut in half.
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. I actually work at a major name auto manufacturing plant. We take a lot of pride in our work. Sometimes I drive myself crazy trying to make sure the customer gets the absolute best product possible. I can understand how the guys you're speaking of feel.
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. They did an amazing job designing and squeezing this setup into the hole provided. That lid and filter will barely come out. Maximum filter for allotted space was achieved. I would guess the 6.0 filter design may have been brought in earlier in the vehicle design process so they had better room to work with.
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 agree with the testing conditions. Ideally they should be back to back but that is not possible. I do not feel like the ambient temperature has a drastic effect on the vacuum which is our measurement of filter system restriction however. I think we have already discussed the boost/power aspect since this is an old quote but I'm so scattered maybe I haven't posted it up. For this testing I am not concerned with how much boost the truck makes. Of course I am tracking it as a reference point of data but my main goal is just understanding the filter system restriction. If/when the filter becomes a significant detriment to power and increased EGTs is where I would draw the line. Unfortunately those items are very difficult to quantify, so I am just paying attention to vacuum. If I am towing next summer and find EGTs to be an issue with the AIS then I will be putting the Donaldson Blue back on to see if this helps.
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. Thank you for the kind words. So far I am very happy with the decision to drop down in turbo sizes. My current selection is definitely not for everyone, but it seems to suit me well. My main concern was a possible issue with EGTs while towing which proved to be non-existent during that trip. Unfortunately the ambient temp was in the 40's that day. I hope to see "similar" results in the heat of the summer but we will have to wait and see.
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. Yes the gauge graduations is a big regret for me in this testing. If I had known how far I was going to take the testing then I would have purchased a more correct application in the beginning. But too late now. The next guy to confirm my data can use a better gauge.
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? I guess I could say my main goal would be to allow the turbo to work efficiently. At some point the turbo would be starving for air. I'm not after the biggest boost number possible, just an efficient system...and quiet, I love the quietness of the AIS!
Responses above in red. I cut the quote up a bit to only have items regarding my responses.
Here is video mentioned above. Stock truck, not tuned, riffraff 360 rebuild with rr 4x4 wheel, stock filter housing.
Truck had a dorman intake boot from ccv to turbo inlet.
This was a bit if a headscratcher to figure out for a little bit. Truck is in CA and I was helping "remotely" from PA
Inserted a temperary metal ring(exhaust pipe cutoff) that was inserted into the boot to hold it open (dont worry it was big enough that it couldnt get sucked into turbine) and verified the boot was the issue, oem boot now installed
@Peixinho I sent a rep point your way for the gracious offer. The information you provide will only bolster what Jason has accomplished and add to the discussion.
Oh, put a sock on it will ya?
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On the 6637. A filter sock. Like the kind that Pete supplied to Clay. Since so many folks use them, might as well add that layer of restriction to one of the testing cycles while at it, no?
@Peixinho I sent a rep point your way for the gracious offer. The information you provide will only bolster what Jason has accomplished and add to the discussion.
I’ll rep him after the testing is complete.
Seriously though, he will be able to much much much better perform repeatable testing on the dyno. This will do far more than bolster my testing. It will give REAL values where mine are just guesses. He will either support what I “think” I have measured or completely disprove it. I’m anxious to see the results. Thanks for the great offer Charlie!
Originally Posted by Y2KW57
Oh, put a sock on it will ya?
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On the 6637. A filter sock. Like the kind that Pete supplied to Clay. Since so many folks use them, might as well add that layer of restriction to one of the testing cycles while at it, no?
FWIW my testing performed with the gauge and 6637 included Clay’s Donaldson Blue and filter sock. There was a definite lower vacuum at the CCV under heavy load when compared to the AIS.
I may do another test with my old used 6637 and the vacuum gauge in the butt of the filter. Previously completed this test with just the FM. This would get a reading comparable to the FM location in the AIS since it is out of direct airflow
Originally Posted by FinnishStroker
I use my wifes pantyhose on my "6637".
I want to say something about how large the 6637 filter is......but I’m trying real hard not to.
