These are the numbers I got from AFE and are probably with a brand spanking new (clean) filter. Keep in mind that AFE wants to sell filters. I have heard from independent testers that if you get 600 CFM out of a PG7 cone filter, you are doing extremely well. If I thought I was getting 600 CFM with good filtration, I would be happy.

AFE PG7 Drop-in: 407 CFM
K&N Cone: 583 CFM
AFE Original Cone: 620 CFM
AFE PG7 Cone: 820

As I stated earlier, once I got my PG7 to where it filters well enough to satisfy me, I could pull the filter minder all the way down to 60%. I couldn't even do that with the stock air box and a new stock filter. Given those results, it makes you wonder......

 

I was getting about 10" hg with factory filter.(replaced "filter-minder"with vacuum gauge) and then cut a five inch hole in the bottom of the box....Now I get less than 3"hg. I hpe this # stays the same or the AFE PG7 is going back in a hurry !. Please , someone convince me that the that this is not true. The higher the # in "hg means the filter media is more restrictive. Has anyone else out there used a vacuum gauge ?,after all the filer-minder is under the hood and only reads peaks. What happens if the filter gets really loaded with moisture or debri while on a long run.We can still get the boost with more throttle (and higher EGT's),until we shut the engine down. Then the debri drops off and the moisture dries out and we never Know the differance..Looking at boost pressures only give part of the picture.I guess this does not make that much differance to a stock air box that lives on the highway,but off-roading with wide open filter face area is another story.
Mark T.

 

AK -- I was thinking about all this flow rate stuff and began to wonder if anyone had done a input flow versus exhaust flow calculation. I haven't -- the thought makes my brain hurt But then I started to think approximations, man. reality checks, you know?

So here goes: say you have 800 CFM of cold air. release that same amount of air into a pipe at 10 times the temperature (in degrees F) and you have alot of flow. We know that air volume at the same pressure is directly proportional to Celcius temperature difference -- so we're talking roughly 5 times the volume of air at 1000 degrees F as 100 degrees F.

The max you'll ever see on a CTD 5.9L on the exhaust side is something like 1600 CFM at WOT and 1200 degrees EGT. So if you're intake is capable of 800 CFM at 100 degrees F, that capabiilty of itself should translate in to well above 1600 on the exhaust side.

I know it isn't quite that simple, as the exhaust gasses are not air. but the approximation reality check made me think that 800 or even 600 CFM of cold air intake is way plenty for our trucks under 400 HP

just a thought.

 

No doubt, but what originally started this thread is I don't think I'm getting anywhere close to 600 CFM. When I put the AFE on, I could run WOT all day and the filter minder might pull down just enough to notice. Subsequent check of the intake tube showed a lot of dust. Re-oiled the filter and no dust, but now I can pull the filter minder all the way down. Good filtration, bad flow.

I don't know what to think is acceptable. I know there is not a filter made that will stop all the dirt, but I do expect to have a clean intake tube after only 100 miles. When I see that the stock filter, new, flows just over 300 CFM, and with that new filter I can only pull the filter minder down to 30%. Now with the AFE oiled to provide good filtering I can pull it down to 60%, that tells me the AFE is imposing more restriction than the stock setup. Am I wrong there? For $300, this was not what I was expecting. I was hoping to hear others' results with the same setup. I guess I'll abandon the AFE to the classifieds section and put in a nice big Donaldson BHAF with a 600+ CFM rating and be done with it. I'm a little disappointed with my results.

 

agreed. And I don't think that (lack of flow) part of your experience is getting the attention it deserves. something is definately wrong here. wonder how AFE determines their flow numbers. have you started running up the totem pole at AFE?

 

Yeah. AFE told me I simply have too much oil on it. They are probably correct in the aspect that I do have more oil on the filter than the way they oiled it at the factory. If it takes "too much oil" to provide decent filtration, then maybe this filter is not for me. I have cleaned the filter, removing all dirt and oil, and re-oiled in small increments to ensure I added just enough oil to soak through all the fibers. At this stage, it was still oiled noticeably more than at the factory. No dust in the intake, but no better flow either. I think I'm done. I'll look at other avenues after my vacation.

 

wow. very enlightening. Given your rather scientific approach, I probably would have arrived at the same conclusion. So what other options are there that yield both high airflow and good filtration? your approach is sound, your method is scientific, your results cannot be questioned, and they show AFE PG7 is thumbs down. bummer.

 

I've been lurking for a while now, and since I just put my AFE in last weekend, I thought I might be able to add to this.

I too thought that the factory oiling was a little light (compared to how I used to oil the K&N's that I used in years past). But after reading the posts here, I decided to just make a mental note of the oil "level" and try to get to that point in the future.

I'm curious if the pre-filter might be the answer to the heavy oil-vs-dirt passage? I havent seen a whole lot of discussion about the benefits of the pre-filters on here or on the TDR.

I'm also curious about the effect of the 3" hose that the filter minder is mounted to. This MAY have a slight real world affect on the vacuum reading of the filter minder - theoretically, it shouldnt. But with the sensor now set back a few inches, rather than right in the "flow", it may be seeing more pure vacuum.

Has anybody who had one of the early AFE's without the filter minder port had any similar experiences????

BTW, I love the more pronounced turbo whistle now!!!

 

A $300 bummer. For good filtration, I guess paper is the way to go. Just have to get one big enough to flow well: https://dynamic.donaldson.com/webc/W...083&item=14142.
Specs: http://www.reliableindustries.com/ph...ch_for=B105006.
On-line order: http://shop.airflowonline.com/Mercha...ategory_Code=D

I used the pre-filter for a while as well. According to AFE, the pre-filter ads a 10% restriction. I took mine off as soon as I was satisfied that the AFE would stay dry in the rain. I only used it to begin with for its water shedding properties.

 

I talked with AFE earlier today and they told me that the PG-7 media flow rates have not been published but are expected to be at about 90% of the std "magnum force" flow rates: From this conversation and from viewing their web site, I draw the following conclusions:

1. The AFE web site indicates that the stock airbox flows at 229 CFM. this is on a 2003 Califiornia model (is that different from the EPA 305HP engine's airbox?)

2. The AFE PG-7 intake system without the torque tube flows at 90% of 297 CFM (The magnum force intake system flows 297 CFM according to the AFE site). Thats 267 CFM, or about sixteen percent higher than stock. big woo.

3. The AFE PG-7 intake system WITH TORQUE TUBE flows at 90% of 497 CFM. Thats 447 CFM, or over twice the flow rate of the stock airbox.

AK, I have no idea how to reconcile these numbers with what you were dealing with (600, 800 CFM for AFE????, 327 CFM stock? whats going on here?).

btw, the AFE flow rate of 447 CFM is at 1.5 inches of water (restriction). The Donaldson filter you mention is 450 CFM at 6 inches of water -- three times the restriction at the same air flow.

 

Doug: Thats good data.....but a couple days late and 250 bucks short!!!

I guess the only thing now is order that dang torque tube.....if their data is believable.

Its amazing how all these companies supposedly only test their stuff on SO's (Banks, AFE, etc)

Did you guys read the thread regarding dyno run results with a VA box? Basic conclusion was that on a stock motor, an aftermarket higher flowing exhaust would cause the computer to defuel....a little deeper than my knowledge of these motors goes, but good info anyway. I NEEEEEEDDDDD A Box!

 

An AFE add I had run across a while ago and kept until I was ready to research which intake upgrade I would use.

 

They also make the C125004 with a 5" outlet flowing:

Airflow @ 6" H2O: 485
Airflow @ 8" H2O: 620
Airflow @ 10" H2O: 760

I guess you could use a 5" intake tube with a last minute neck down to 4" just before the turbo and squeeze a little more air out of it.

 

Dang...Didn't need to hear this...Especially now that my new PB7 intake and T-tube are in the mail right now.

What I would like to know is why the heck a torque tube is going allow more air flow than the stock 4" system (with baffles removed). I could understand a little more flow, but 35% more than with a stock tube and the PG7?

****...Once again it appears that I jumped a little too early. Everything I was reading about the PG7 stated it being the best thing out (still could be if all the manufactures are lying through their teeth about their "performance" equally but crap is crap). Man this has the potential to suck about 350 ($) times.

Now (down a few posts on this list) there is a thread on the 305/555 defueling with a 4" free flow exhaust. This was proven by plugging in a VA box, but leaving it off, as compared to a dyno run without the box plugged in....The dyno showed a marked DECREASE in HP/Torque with a 4" straight through exhaust and no boost fooling/box-off installed. Hmmmmmmm. Maybe DC's engineers are right and the aftermarket manuf's are digging, through deceit, to squeeze $ out of us with nothing to back up their claims....Kinda' like Weider body building products (DUH!!!)....We REALLY WANT to believe...But...

Now I realize this is only one incident, and I’m still gonna’ install my PG7 and see what happens, but I’m beginning, through the power of the net, to desire to keep my 04 stock for a year or so until this all works itself out in the end.

--Doug


--D

 

Now what fun would that be?