I found this in other forum, check post #11, about filter covers, What do you think. I always have thought that the filter should reduce the flow in some way. IDK.

Cold Air Intakes - Page 2 - PowerStrokeNation : Ford Powerstroke Diesel Forum

 

It does make sense that the cover would reduce air flow or create more restriction. My cover is off of mine right now because I washed it. I wonder if there is some way to test if there is a significant difference or not???

 

OK that's it I am going back to panty hose

 

That's what I have on mine Rich, an old pair of my wife's black panty hose! LOL!!

 

Let me be the first to suggest that the difference in performance between having the filter cover and not having the filter cover is most likely negligible.

 

Yes that would be very good.

How did you know: do you have flowometer?, or is just your appreciation?.

 

I don't know. I made a suggestion. I chose the words that I used very carefully.

 

Dont get mad mi amigo Joseph.

I asked to Dale about this in this was his answer:

Jose,

The flow rate is not what you should actually be interested in. The flow rate only defines the ability of the filter and would be highly pendant on too many outside variables to properly compare two different configurations in an A/B style test.

If you use restriction as a testing measure you can measure how much negative pressure exists, or how hard the turbo has to suck, which is really what you want to know. You need to find out what what kind of energy you're losing that could be making boost for you.

You need to be a little careful when measuring restriction because placement of your sensor and the angle at which the sensor draw tube is inserted into the air flow stream can all impact your results. You need the sensor positioned so that side wall draft is not affecting your reading. You also don't want any additional pressure by placing the sensor into the air flow or vacuum by placing the draft tube away from the air flow to affect your results.

Another consideration should be that, even if you can do testing on a filter with and without the filter cover, it will not be reflective of what will happen when you are 1, 2, 3 or 4000 miles down the road. Obviously trading 4000 + square inches of surface area with just under 200 square inches of surface area will yield drastically deferent results once contaminant accumulations star to occur.

With testing results we have done internally we have found that the majority of your benefit by going to an open element is mitigated by placing a filter cover over the filter. By the time you have very minimal service duration you are not only losing whatever you gain but you go negative to what you should be experiencing very quickly.

I hope that helps, feel free to copy and post this as my response if you would like to include this information into your discussion.

Again, nice hearing from you,

 

I got the riff raff 6637. I never installed the pretty red filter cover. thinking it would be more restrictive so I never put it on. also I couldnt really get it to go anyways so I gave up on it and threw it on a shelf in the barn. been there ever since. Im about to change that filter since its kinda dirty. adding anything to a filter is bound to make it more restrictive i would think. it sure isnt going to make a filter work better than the filter alone IMO.

 

Im with you on that.

 

Actually the covers were flow tested and the affects were so minor it was almost unable to be measured.

 

Its similar in effect to cup cars designing air fleaners that straightened the air flow out.I would have one on mine but I'm cheap...

 

Any link to support that?

 

The only two parameters that matter when it comes to particulate filtration are:

1. filter pore size and
2. total open area of the filter.

clearly these two are often inversely related, which is why you wind up wanting alot of surface area when the pore size is small, but filter surface area as a parameter by itself is worthless. in this case, these two will tell you how much air will get through to the engine (what you want) and how much dirt/dust will not (what you don't want).

no matter how you slice it, all other parameters can be boiled down to these two. who cares what the total surface area of the filter is - if it only has a few holes in it, it could be as big as the whole outdoors, but you're not going to get much air through it.

in the case of these bags, my guess is that (and its just a guess until next week when my 6637 setup shows up in the mail from from Riff Raff) there are lots of very large pores, so that even though the surface area may be much less than the filter, the airflow through is probably comparable and not hurting intake efficienty much (though it would be terrible as a stand-alone filter).

on the other hand if what is said about K&N and other reusable filters is true, the problem is clearly that their filter pore size is too large and allows fine dust particles through.

for what its worth, i'll be swapping my current K&N filter with a 6637. hopefully it just clamps right on the K&N tube... my K&N has only been on for about 500 miles, so hopefully i havent done too much damage - though i put it on just wanting to get the old original 96 stock (recalled) air intake off, but before hearing about the 6637. my turbo compressor blades are nice and shiney and two of them are bent - clearly alot of crap has made its way into my motor over the years. wish i knew to look for that before buying the truck. i'll be doing a new turbo soon, and with the 6637, hopefully things don't get any worse inside my engine than they already are...

 

Don't worry, José, I'm not mad. I specifically used this little guy () to try to communicate that fact. I just wanted to make sure that it was clear what I was trying to say in the first place. I wanted to make it clear that I have no data or experience at all that would be useful in supporting my suggestion.

My tone in this thread may seem severe, but I assure anyone reading this that I have no bad feelings going on or anything.

I'm also going to throw this smiley in because I like it and don't get a chance to use it very much, lol.