The new FRAM filter I bought has two strips of adhesive which connect all the pleats, I imagine some filters without this stiffening measure got sucked in as no other FRAM filter has that.

 

The K&N passes way more dirt than a paper filter. They are good for the dragstrip and on street legal race cars as the K&N is better than no air filter preventing large sand from getting sucked in, but for an engine that you expect to live more than 50k miles it's no good in my opinion. My dad's late 90's Chevy van has a filter which looks like a paper towel mega-roll, I'm going to see if that will work on my truck as he gets more than 30k miles per filter on his.

 

Here's a caution that's quoted from the K&N web site that supports my concern that due to their shape any "cylinder type" or as the Banks web site calls them "filters on a stick" can distort and even collapse under load if they're allowed to become too restricted...

"The maximum allowable restriction for a K&N Filtercharger is 15" of vacuum (water). If the restriction is allowed to go higher, the filter media might become so restricted that the element could distort allowing dirty air to bypass the filter and enter the engine."

As discussed in this thread ...Cold Air Intakes https://www.ford-trucks.com/forums/8...ml#post7095109 ...a very good filtration efficiency is required for removing particles that are 10 to 20 microns in size which do the most engine damage and my compressor wheel picture after only a few hundred miles of towing with a freshly oiled K&N demonstrates that at least my K&N wasn't up to the task of filtering these small size particles!

 

Somewhere there was a post that someone (I believe it was Dale at Tymar Performance) did dyno runs and found that the 6637 open element intake didn't give up any HP to a comparable "cold air" setup.

 

If you read this thread from post # 75 to the end and especially post #90 and post #102... https://www.ford-trucks.com/forums/8...n-turbo-5.html ...you'll see that I refuted the misleading claims on the Dale Isley Tymar Performance web site!

His misleading approach of averaging the under the hood temperatures between a colder ambient air location and a warmer one is the same as me claiming that my current life savings is the average of what I had a year ago and what I've got today! Not only that but he only took measurements while running around town empty!

Also the issue isn't about your maximum HP on a dyno run where the hood is usually open anyway and the engine compartment hasn't experienced a 2 hour "heat soak" due to towing grades on a hot summer day, but rather as I said in post #14 on this thread the real issue is that the hot intake air from under the hood is making your turbo work harder to flow more CFM to make the same HP because more CFM is needed to produce the same MAF to get the same HP because of the lower density of the hot under the hood air!

I think all those who currently use or plan to use a "6637" filter should considering the following.

The WIX 46637 is cross referenced to a Baldwin PA2818, and to a Donaldson B085011, however I doubt these three elements are of equal quality and more than likely the cheaper brands are of lesser quality and the maximum temperature rating for the highest quality Donaldson B085011 is already somewhat troubling!

The WIX site lists the WIX 46637 with a CFM:425 at the end of the spec list, but it doesn't give any "H20 vs CFM" restriction data.

Here's a link to the Donaldson site site...
http://www.donaldson.com/en/catalogs/engine/033621.pdf

... and it gives the following restriction data.

ECB Initial Airflow Restriction
CFM @ "H20 Air Cleaner
4"........6"........8 "......Model
280....400....470......B085011

On the Donaldson site the stated application for the B085011 filter is for gas and diesel engines in light to medium dust conditions. So this filter doesn't seem to be a good choice for the dusty conditions that many trucks encounter!

The Donaldson site also states that for the B085011 filter the temperature tolerance is 180 F continuous and to keep the filter away from the engine manifold and other very hot components because the DuraLite is only rated at 180 F maximum sustained temperature. I know for a fact that my F350 under the hood temperatures exceed 205 F on many occasions because that's the air temperature that causes the radiator fan clutch to lock up!

The Donaldson site also states to keep the filter away from battery acids, brake fluid, and other caustic fluids yet the in a 7.3L application the filter is mounted near the master cylinder and battery!

The Donaldson site recommends a 1.5" overlap and the use of a special Donaldson high torque hose clamp for their DuraLite air filters. I recall reading about problems with unfiltered air leaking in at the neck of these filters and sometimes the filters come completely disconnected from the intake tube!

The Donaldson site recommends to not judge the filter on the basis of a visual inspection but to use a restriction gauge that's located between the filter neck and the air intake to the engine. I've read many posts about how dirty should a 6637 get before it needs to be changed and most seem to have their restriction gauge located at the end of the filter where it can't sense the full filter restriction!

Here's why you need a restriction gauge that's mounted in the correct location... Heavy-Duty Diesel Engine Air Filter Collapse... http://www.filtercouncil.org/techdata/tsbs/06-2.htm ! If you get a leak in the up-pipes note that soot can plug an air filter rapidly and shorten the life of a filter dramatically, and if a restriction indicating device isn't monitored closely can result in extremely high pressure drop across the filter that may cause it to collapse.

 

This info is from FleetFilter.com. The stock filter is rated at 260cfm. The 6637 is rated at 425. NOBODY, not even Gene has proven that the filter under the hood makes all that much difference IN THE REAL WORLD. He has tons of formulas, quotes from Gale Banks (YAWN), etc, etc, but when tested ON THE DYNO, the 6637 flow and performed nearly as well as NO FILTER at all. That was done with the hood up, and several filters were compared. To his credit, there has been one case of a filter coming apart, but there were no pics, and no post-mortem study done on the filter to see if it was a manufacturing flaw or a case of it getting wet. I have been through torrential downpours on the high way, and through flooded streets with mine, and it has never gotten wet. You really would have to get into some nasty water to let the filter get soaked. I'd even argue that Gene's "Gene-Dad" mod would allow more water in the stock filter than the 6637 would get.

I'm sure he'll tear me up on this, but I'm done arguing about it. I state my FACTS, he states umteen formulas and opinions, none of which changes the fact that on the dyno, the 6637 is an excellent performer, even with the hood down, and it filters just as well (per OAs) as any of the other good ones.

 

Keep speaking the truth, Gene.

Yessiree, nothing I like better than some good 6637 bashing.

 

--- YAWN ---

 

Here I'll give you the benefit of the doubt and assume that you don't know any better because your above statement is distorted and misleading just like the ones you've repeatedly accused Banks of making and I summarized those accusations in my post #30 here... https://www.ford-trucks.com/forums/8...ml#post7228722 ...and I'm still waiting for you to respond to the challenge I made there!

According to my data the stock filter is rated for a 260 CFM flow at a restriction of 4" H2O and from the Donaldson site the B085011 =? 6637 filter is rated for a 280 CFM flow at the same 4" H2O restriction which is only a 20 CFM higher flow at the same 4" H2O restriction and not the 165 CFM higher flow that's implied by your statement!

The reason I used an =? is because there's no guarantee that the cheaper WIX 46637 version actually flows as well as the Donaldson B085011? The WIX site lists the WIX 46637 with a CFM of 425 but it doesn't give an Inches H20 restriction at this 425 CFM flow and without knowing the Inches H20 restriction at a given CFM flow you really don't have any meaningful information at all!

Your statement also implies that a stock air filter can only flow a maximum of 260 CFM but at the RPM=2,600 and BP=17 psi for its maximum HP my computer model for a stock 99.5 version of a 7.3L indicates a MAF=Mass Air Flow lb/min of MAF=35 lb/min and a AFIVAF=Air Filter Inlet Volume Air Flow ft^3/min of AFIVAF=480 ft^3/min=480 CFM. So it seems to me that Ford must've designed the stock air filter to be able to handle a 480 CFM flow! Based on this it appears as though this statement from post #11 must be pretty close to being the truth after all...

From the Donaldson site the B085011 =? 6637 filter is rated for a 400 CFM flow at a 6" H2O restriction and for a 470 CFM flow at a 8" H2O restriction, and my ballpark estimates are that a stock filter will flow 370 CFM at a 6" H2O restriction, 435 CFM at a 8" H2O restriction, and 500 CFM at an 11" H2O restriction and that the B085011 =? 6637 filter will flow 550 CFM at the same 11" H2O restriction.

Keep in mind that any filter will flow a higher CFM at a higher Inches H20 restriction! The issue is what's the maximum Inches H20 restriction that a filter can withstand before its supporting structure fails and allows it to collapse?

According to the caution on the K&N web site "The maximum allowable restriction for a K&N Filtercharger is 15" of vacuum (water). If the restriction is allowed to go higher, the filter media might become so restricted that the element could distort allowing dirty air to bypass the filter and enter the engine."

According to the quotes below a 6637 is also subject to collapse if it's operated at too high a restriction...

From post #8 here... https://www.ford-trucks.com/forums/6...7-testing.html ...
From post #9 here... https://www.ford-trucks.com/forums/7...st-6637-a.html ...
From post #11 same thread...
Please re-read my post #20 on this thread and let me know what you didn't understand about a dyno run not being the issue...

This statement is also distorted and misleading just like your one about stock vs 6637 CFM flow but since you've replied on most or all of my dozen or so threads on this topic you should know better so I can't give you the benefit of the doubt on this one, but I'm too tired out from doing some "REAL WORLD" towing through the desert mountains to address it just now so I'll reply to it later.