Is the consensus that the AFE big boost is a better filter than all variants of the 6637? I had thought that installing that big bish I had more filtration and air flow than I'd ever need, but reading this thread has me reconsidering replacing in kind and spending a few more bucks on the washable filter.

 

Yup, I made a typo because I hastily moved past the title in order to list the bullet points. I didn't realize it though until after Y2KW57 posted a thorough and detailed post about chocking. I am happy he didn't go with "chalking" though, as I may have missed the point.

Crap happens and at least that mistake was taken with humor and didn't require a fix action.

My current course if action is when I need to replace the Donaldson 6637, I plan to go the AFE route like seen on the KC Turbos site. Not because they said it flows better/more air and definitely not because it is more than twice the cost. I feel that a washable and reusable filter has a lot value if the intended use is over a long period if time.

I will make sure it is a dry filter though before purchasing. I run a washable dry filter in my other vehicles as well and like the versatility they provide.

All of that said, RacinJasonWV has shown us that even the AIS is capable of great air flow, so I say go with what suits your needs and makes you smile.

Brokestroke brings up a good point about commercial diesel applications that I cannot speak to, but am interested in learning more about it.

 

Well “great” air flow may be a stretch but how about more adequate than was previously thought. So far the AIS with fender sleeve is suiting my needs very well with the T4 363/68. I am a bit of an oddball though.

 

Shh! We know and love but don't advertise!

 

It's been several years since I've had my head in the pre-filter game, so my comments below are just shooting off the hip, but I'll offer a couple of points to ponder and add some facts to some of the questions/comments I've noticed at a glance in this thread.

1) All of the filter covers I used to make for Clay were double knit, 100% polyester, and had some stretch in them. They had a great capacity for air flow (read as very low restriction when clean). One customer ran a cover on a new 6637 on a Flow Bench, and at 1000 cfm, there was only about a 1% reduction in airflow with the cover. Keep in mind that 1000 CFM is about 2.5x higher than what is is rated at, IIRC, and that the amount of restriction would decrease with reduced air flow rates. For those of you who purchased covers through either Clay or directly from me... another big Thank You!
2) All of the current covers sold by Clay are a completely different fabric with a completely different structure. I am not saying, proposing, or even suggesting that one is better than the other -- they are simply different, and each will have it's own set of pros and cons. I have no data or insights on the airflow restriction (or lack thereof) with the new covers, aside from what I just stated. I can say, though, that the thicker, double-knit construction of the early covers would naturally have a higher dirt holding capacity than the current ones, but that is not always a significant issue at all for those who stay to the pavement in non-desert conditions or those who do not spend much time on dirt roads.
3) Do not ever get sidetracked (suckered) by any sales pitch about using "water resistant" or "water proof" pre-filters -- it's a marketing claim which, pardon the pun, doesn't hold water.
4) The "Big Boost" has an inner cone at the end of the filter body which provides more filtration surface area, and this means several things...
a) a pre-filter will not be as helpful on the Big Boost because the current covers on the market do not have a flat (or conical) end panel to protect the inner cone,
b) you can get more air flow with the larger filtration surface area, and
c) the larger filtration surface area can be realized by either lower air velocity and better filtration, or longer life for the pre-filter and filter element, or a combination of those two.

No new insights above... just wanted to float a few facts to the surface.