@udsuth78 , you wrote the following in another thread and I was hoping to expand on it a bit more without hijacking the original thread.

Quote source: https://www.ford-trucks.com/forums/1661130-low-boost-high-egts.html#post19870784

• Can you tell us what cover you have on the 6637 filter?
• Is the filter a Donaldson blue or the white 6637 filter?
• Do you know what the filter cover is made of?
• What turbo are you running and what modifications are in it if any?
• Is the rest of the intake tube OEM or aftermarket?
• You hand washed the filter cover and not the filter right?
• You saw an increase in boost pressure "without" the filter cover correct?

Any other points or details you can share? I have not really seen this discussed before, at least not that I remember and am intrigued.

 

Interesting. I am running the white paper 6637 with a black RR cover. Always hand wash it during a filter change. Their design appears to be pretty free flowing. Good topic of discussion.

 

I agree, interesting... I read it several times to make sure I was understanding the message and decided to create this thread.

I run a Donaldson blue 6637 type filter with a black pre-filter from Riffraff. It is the old style which is thin cloth material that was made by the F250_ family. The new style pre-filter is not the same material best I can tell.

 

Staying tuned. I run a blue Filters Wear brand from Amazon on my 6637 Donaldson Blue also.

 

Pantyhose cover FTW!

 

Yes,i used pantyhoses before but now i have the RR cover in Blue Donaldson.

 

Was running the Filter Wears brand cover on a Wix 6637 filter.(red for the truly inquiring minds) I couldn't say what material it's made of. It's advertised as water resistant and to and extent it does wick water, but is also see through. My turbo is a stock E99 w/ billet 5+5 wheel on a L99 ebp delete pedestal and up pipes. The intake tube is diy mix of silicone pipe, obs parts, and og.

I had spilled some trans fluid on the cover while filling power steering so I pulled it to clean. While it was drying I had things needed doing so installed new filter without cover and went on my way. Took less than a block to notice the difference. Way more turbo spooling whine and I can hear the air being drawn in from off idle all the way up. Haven't put the cover back on since. Does need something though I think, the filter is getting dirty quicker, may have to raid my daughters room to try the pantyhose idea. She's off at college she'll never know, and if she does I'll just invoke the 24 hour rule.

 

The old style RR cover is very similar to that, maybe 2x or 3x thicker material. It is quite thin and flexible, but does a good job as a pre-filter.

If or when I replace the pre-filter, I was intending to go this route David.

 

I had not heard of that filter cover until you and Cousin Carl mentioned it. At first I thought your instance of using "Wear" was a typo or an auto-correct that was incorrect.

Perhaps the correlation is as simple as the E99 turbo... Another FTE'r with an E99 turbo claims max EGT of sub 1000° while towing heavy on an extreme tow tune with an E99 turbo, but I am not familiar with his intake system. Perhaps I will browse his gallery for an applicable photo.

I am not familiar with the design differences of the E99 vs. L99 Garrett GTP38 turbos. I believe the OBS has a TP38, but again I am not sure.

Being that the rest if your intake is DIY silicone tubing, I would not suspect this to be the cause of the restriction, especially if the difference was noticeable once the filter cover was removed.

Just to be clear, you had a used filter and cover, removed both for cleaning purposes and installed a new filter without a cover?

I agree 100% that the 6637 style *blue or white" needs something. Due to the cost and convenience a pre-filter makes sense. I really like the old style (F250_ version) from Riffraff, but some mice chewed a hole in it a couple of years ago. I rotated the hole to the bottom where the filter rests on the wheel well and hold down clamp.

Interesting and I will have to think about this a bit.

For reference: Filter Wears 6637 cover

 

This winter, my plow truck which has an s&b intake had the filter collapse because of the s&b filter cover. Between all the moisture (snow/slush) coming up over the plow and into the grill, and the occasional hudrolic fluid coming up out of the plow motor pressure release vent blowinging into my grill, the filter sock became a slimy non flowing bag, truck lost power, more black smoke etc. I installed new filter and gained like 100hp back, next winter I plan on removing the tube to the grill from the intake to avoid as much mess getting sucked in :-)

 

Eric, at the time of the filter collapse, were you using the plastic, flat, see through cover on the S&B intake or was the plastic cover off?

You go on to say "filter sock", but we as people from different walks of life often call the same thing different names or have different descriptions. Do you have any ideas about what the S&B pre-filter is made of? Does it appear to be of a thin material resembling panty hose or is it more water resistant and non-porous like a thin wind breaker jacket?

Where did the pre-filter (sock) come from in regard to supplier or manufacturer, do you recall?

 

The clear lid was in, the filter sock is a thin breathable material, it is an official s&b product that s&b sells in different specific sizes for their wide range of filters. In my experience, they are basically the same material as any other quality sock.
From years of running filter socks, I find that they work great in dry dusty dirty environments, the keeps lots of larger debris out filters. Get lots of moisture in em and dirt sticks, wet dirty environment require more washing of sock. Get oul or similar fluid on it-toss it. Udsuth78 said he got power steering fluid on his? Which is atf, which is hydroli fluid, which goes in my plow pump, which ruined my sock. Keep in mind my truck was being used in such harsh environments that my windshield wipers were having to be used to constantly clear dust off my windshield, while cindering... Yea horrable and unusual.

 

Why is that? I have a RR cover, but haven't run it in years, after noticing slightly lower boost with it on.

Mark

 

I feel this isn’t a fair comparison since a new filter was also used. The sock would need to be installed with the new filter to make sure it was the contributing factor. Then a new sock should be tested to see if the oiled sock has caused an abnormal restriction.

FWIW, Charlie from KCTurbos has said multiple times that he has seen issues on the dyno with the 6637 filters not flowing like people think they do.

 

This is just my opinion, as humble as it may be. My thoughts are this... When I ran the AIS for many years traveling cross country and towing with the modified stock turbo, it did very well. But, the filter media difference between the AIS and the Donaldson blue 6637 is vast. I cannot speak for the white 6637 as I have never owned or seen one up close other than the ones in places like Tractor Supply.

I feel that a thin material like a porous pre-filter is a great way to extend the life of a Donaldson blue 6637. I know I frequently clean my pre-filter cover when changing oil or performing some other maintenance task due to pollen, dust or whatever. I feel that if these "contaminants" were being allowed to imbed themselves in the Donaldson blue 6637 filter media or folds, the cleaning task would become much more cumbersome and costly over time. In my opinion, the pre-filter allows for the life of the 6637 to be extended greatly which is a win for me. Easy maintenance and lower cost over time.

I have had this Donaldson blue 6637 on since December of 2018 and it looks new still. I cleaned it up when I had the turbo out a couple of weeks ago and it was still very clean. It needed a good "shake", but for the most part it was in great shape. Granted COVID hit the country last year and our traveling with the truck and 5th wheel was severely degraded, but we still managed to get up to Philadelphia, over to the beach 3 times and many sub-100 mile trips with the truck and 5th wheel since December 2018.

It is interesting that you also notice slightly lower boost with the cover on... If you had to take a WAG, what sort of number would you put on the "slightly"? Would it be .5, 1 or 3 PSI and when are you noticing this lower pressure? Is it at WOT, cruising at 2000 RPM or across the entire range?

I cannot say if the pre-filter is actually a pre-restrictor or not. Frankly, I have never ran the truck with the Donaldson blue 6637 without a pre-filter.

Interesting... Perhaps my thinking on this pre-filter is skewed and I need to reevaluate...

The "new filter" was not know to me until this morning and that is why I quoted udsuth78 again, just to be sure we were on the same sheet of music. When looking at seemingly miniscule changes and observations that are relayed via memory, we have to be as clear and precise as we can. Despite the fact that a new filter may have been installed and reset the clock on the filtration, it appears that a pre-filter has been a concern or thought for more than a couple of FTE'rs. That is based solely that this thread was created 12 hours ago and already has several levels of input from different FTE'rs in different areas of the country.

I had not seen the comments from Charlie from KC about the 6637... Do you have a reference or a direct link to his words or video? If this is in your AIS review thread, I apologize for missing the 6637 portion from Charlie...