Belgrath04

I was looking at various intake systems, specificaly those made by AFE, Banks, and True Flow. While Looking over their sites I noticed that

AFE http://www.afefilters.com/productrev...3/75-80933.htm

Shows Stock air flow at 180 CFM and an increase to 289 CFM with their system Measured @ 1.5” H2O

Banks http://www.bankspower.com/newproducts-2-06ra.cfm

Shows Stock at 422 CFM and an increase to 682 CFM with their system Measured @10” H2O

The difference in their stock values 180 vs. 422 is a sizeable gap.

True Flow http://www.trueflow.com
Claims their systems air system flows over 1000 CFM Measured @ 19" of H2O

So I guess my question is in regards to the 1.5” vs. 10” vs. 19" of H2O. What exactly does the inch of H2O imply and how does the difference affect the test results.

DevilzTower

Bel, It's been a while since I've been involved in that type of test, but from what I can remember .... the inches of H20 qouted on those tests refers to the amount of pressure differential between in the outside air and the air going through the intake itself. This has a direct correlation with the velocity of the air going through the intake. So ... the tests with 1.5" of H20 the manufacturer isn't drawing much air through the intake (to simulate the sucking of the engine pulling air) so maybe they are trying to replicate the engine idling. With the higher quantities of H2O" those manufacturers are trying to show how much air they are pulling at WOT or near WOT with high pressure differentials.

So bascially what this boils down to, is that unless you get the manufacturers to use the same amount of H2O (vacuum pressure) on their tests, of have the ability to extrapolate the data somehow it's virtually impossible to compare those numbers together.

Which is one of my biggest gripes about that aftermarket intake manufacturers, they hide the real numbers (apples to apples) so it's very difficult to disern between a good intake and just an OK intake.

However, in terms of product design and construction the aFe and the Banks have a very similar design. Both have a large top mounted conical filter, pulling air from the a lower forward facing location and the fender. I like both intakes in terms of their design and construction, can't say I know all that much about the trueflow so I won't offer an opinion.

D45

Just to give you some related CFM numbers:

The December 2007 issue of "Diesel Power" does a "Deep Breathing Upgrade" (starting on page 70) on a 2008 Ford Super Duty with the 6.4L motor.

In this article, they add a n AirAid 'cold-air' intake on the Ford.

First, they tested the kit with the top of the filter exposed, which resulted in 1,185 CFM.

They then topped the kit off with a steel plate (to stimulate the hood being closed), which resulted in 1,065 CFM.

From published data, the 6.4L motor needs 744 CFM for the motor to make full power.

So, even a less than decent kit like AirAid flows more than the stock motor will ever need. I think it just comes down to how well you want the filter to catch dirt........

Also, if you look at the S&B Intake ads in the January 2008 issue of Diesel Power magazine, it states this:

2003-2006 Cummins 5.9L
Part Number 75-5033
Air Flow Rating: 43.0% Better Than Stock
Efficiency Rating: 99.16%
Testing Conducted at Vehicle's Max Rated Flow: 526 CFM

SO, I assume that maybe this means the CTD needs 526 CFM for the motor to make full power...........

Ford's 6.4L motor needs 744 CFM for the motor to make full power, possibly because it is a twin turbo motor.

So, would this mean that the S&B Intakes flows about 752 CFM.


I emailed K&N, concerning their 57-1532 Kit:

"Thank you for your interest in K&N products. That filter will flow at
1063 CFM. If you have any further question please call our Customer
Support Team at 1(800)858-3333 and an agent will be happy to assist
you. Thank you for writing and have a great day.
Sherri Sykes
Customer Service Agent "

The filter that comes with their kit is P/N RC-4780

Amsoil offers a direct fit replacement filter for this kit: EAAU-4095


Here is a good link with CFM numbers and various levels:
http://www.aempower.com/files/dryflo...iraid9inch.pdf

http://www.aempower.com/files/dryflo...andcleaned.pdf


http://www.aempower.com/files/dryflo...eabusetest.pdf

DBLR

I think the other important question is how well it traps and holds dirt and keeps it out of your engine.

gus's 03

presure drop is what the filter minder reads. presure drop is bad. its a restriction.
yes, by incresing prsure drop cfm will go up (sucking harder)

ruel of thumb for a naturaly asperated motor is 1"

Belgrath04

Great,
Thanks for the clairification Devilz, confirmed my suspicion on their numbers.
D45 thank you very much for the test data, always enjoy getting to look at their technical numbers.

On a side note, the AFE & Banks filters are the gauze type filters and the True Flow is actualy a dual density foam filter. Coarse outter and fine inner layers, I think I am going to try out one of theirs as they are something different and mid range for price.

bob4x4

Flow #s are nothing w/out knowing the restriction the flow is at! AFE uses 1.5".
This a tiny restriction,The largest flowing filters maxed out there flow bench capabilities.I don't remember the exact# but it was somewhere over 1100 cfm @less than 1.5".This is huge compared to 1100cfm @ 20" of restriction
The lower the resrtriction# the more accurate the test will be.I have been told by an fluid dynamics engineer at high restriction #s too many variables can render test inaccurate.

Bob

bob4x4

[QUOTE=DevilzTower;1848236]Bel, . So ... the tests with 1.5" of H20 the manufacturer isn't drawing much air through the intake (to simulate the sucking of the engine pulling air) so maybe they are trying to replicate the engine idling. With the higher quantities of H2O" those manufacturers are trying to show how much air they are pulling at WOT or near WOT with high pressure differentials.

I do not think that is correct.............
The amount of restriction just shows you how hard it is to suck (or blow) air through the product.

Bob

bob4x4

I beleive some manufacters use higher restriction #s because the numbers seem or appear to be better to the uninformed

Bob

Belgrath04

Bob, who's filter flowed (is that a word?) over 1100 cfm @ 1.5"?

DevilzTower

bob4X4 you are exactly right, I should have qualified what those examples were suppose to mean. I was just trying to show that the trueflow and banks tests were performed and factors of magnitude of 5-10x the aFe tests. I didn't think those numbers would actually correlate to anything in the real world and should have mentioned that ... opps.

bob4x4

AFE ,the race version on my 12v. 6" inlet filter instead of the standard 4 of the stage 1.

Bob