Flow Bench Test Results

[Jim Allen]

The results are in! And with some very interesting results. First off, this material will be going into a future issue of a magazine (to be mentioned at a later date) but I'm giving you guys the results first because I got the idea from you and you deserve the credit. I take the risk of somebody burning me by using the info somewhere else, so that at least oughta bring me up to Double Whopper status!

Also, in the story I will credit you guys for the mod in whatever way you think is appropriate... and is politically correct for the magazine, of course.

WARNING WILL ROBINSON!

Look close at the two closeup pics to see what happens to the downspout tube at high flow rates, so all of you that have done this may want to trim most the the excess back, leaving just enough to center it in the fenderwell hole. This problem occurred at the maximum flow rate of the housing. It may not occur to a stock truck (see 5.4L theoretical airflow below) but it's probably worth the time to fix it.

The tests were performed by two classes at the University of Northwestern Ohio's High Performance Fuels Class, at their School of High Performance Motorsports, on a Superflow SF-600 flow bench. Each class double checked each result from their class, but each class used a slightly different protocols (both standards in the industry) and I have averaged the results.

NOTE: A 5.4L V8, given 90 percent volumetric efficiency, at 5500 rpm, needs 473 cfm of air. Giving it more than it needs at any given time doesn't necessarily offer any more power. Bear that in mind when reading these results.

Condition/ Average Airflow

1- stock housing & filter, as installed in vehicle- 621 cfm
2- same as #1 but with AEM filter panel- 592.36 cfm
3- stock housing & filter but no silencer or snorkel- 656.83 cfm
4- same as #3 but with AEM panel filter- 632.50 cfm
5- same as #1 but with snorkel tube modification- 597.3
6- same as #5 but with rubber downspout adapter removed- 637.5 cfm
7- same as #5 but with AEM panel filter- 569.51 cfm
8- same as #6 but with AEM filter panel- 619.70 cfm
9- same as #3 but with silencer only- 632.50 cfm
10- Brute Force Intake (for 2004 model)- 733.30 cfm
11- AEM filter only- 1077.25 cfm

You can reach your own conclusion over what this all indicates and I will share mine later if asked

[OneTomcat]

So the bottom line is changing adding or removing anything from the stock air induction is nothing but window dressing?
.....well, it does keep several businesses going

[jimmyv13]

Very interesting results. I did wonder about the flexibility of the downspout as I was installing it the other day. Looks as if I may be going back to the set up. Great job, thanks for the research!!!

[Jackpine]

Yipes! Sure don't like that "pucker" effect!

But now I'm a bit confused. Your tests showed that the stock setup provided ALL the airflow, and then some, that the engine needed at 5500 RPM? More than 473 cfm CANNOT add to power? I can accept this, if the 473 max is correct - in fact, there's no way the engine would take in more than this amount, right?

But, it appears from Bill's dyno testing of an 09, that there IS an HP boost with the snorkel removed, suggesting that the engine IS capable of "sucking" in more air than is available in the stock configuration and mixing more fuel with it - resulting in a bigger "bang".

So, I'm left wondering what is causing the inconsistency. You measured airflow. Bill measured HP. I'd like whatever gives me more miles per gallon of gas.

- Jack

[SubiGT]

I think there are some other factors that go into this power equation besides CFM capability. I would be interested in seeing the pressure differential that the each combination made, as well as any velocity measurements. How many seconds did each combination take to stabilize at those flow numbers? I'll take a fast 569cfm over a relatively slower 623cfm. Time based rate of change is the key to torque(and HP). Also, what was the swept area of each assembly? What volume of air did each hold?

The stock setup might flow as much or more air on a flow bench, but how much work does the engine have to do to get that air from the fenderwell to the MAF sensor? Pumping losses and airflow velocity need to be accounted for.

Know what all those chambers on the sides of the air tube do? Reduce flow noise by reducing velocity.

mass flow rate in=mass flow rate out. mass flow rate=densityXareaXvelocity
for a constant density fluid(air), an increase in area will have a corresponding decrease in velocity.

Looking at the results, I think the leanest running (un-tuned) would be the ones flowing significantly more then the stock combo. The larger numbers(733 and 1077) will trick the MAF by cooling the heated wire too fast, and the fuel/timing tables wont be enough to keep you from running lean. Most of the test intakes flowed within 10% of stock CFM, which the ECU should be able to account for, granted that the you have consistent fuel, a decent state of tune, a clean filter, good spark......


I hope my basic understanding is not too far from the truth

[88Racing]

Okay a great "Thank you" to Jim and the classes doing the bench flow testing.

So sorry I can't post a link to the Ford GT forums right now but there is evidence over there that they are getting the most bang for the buck with the OE setup. The only differences that they have found into boosting the air flow is changing out the intake, TB, and porting everything.

Let me tell you one thing you thought we are serious about our trucks. OMG they pick things apart over there to the paranoid level.

Okay now why I mentioned the other forum is this: the basic deduction of why more air through the stock set up?

More surface area of material used for filtration. Take an old stock panel apart and a aftermarket one and see for yourself. Not unless they are using a more porous material.

Found another indepent company whose research concluded that a lot of cai's were worthless unless they were S+B, Banks, and any other company that uses a poly type tube over a metal one. Their reasoning is the metal ones are acting as heat sinks and the hot air build up causes HP reduction and more unstable air.

Whats the reasoning on fast cfms and slow cfms? I thought a cfm was a cfm unless its reading was affected by humidity and or elevation and or barametric pressures?

I also have another theory going about the reduction into the fenderwell but haven't gotton all the evidence on it yet.

Lars

[Punisher]

Does anyone know if these images/vids are available somewhere else now? The links below are no longer valid. I'd like to see the visuals that this thread keeps referring too. I know this was almost a year ago but some of us are just catching up.

Thanks,
-Punisher

Originally Posted by Jim Allen

The results are in! And with some very interesting results. First off, this material will be going into a future issue of a magazine (to be mentioned at a later date) but I'm giving you guys the results first because I got the idea from you and you deserve the credit. I take the risk of somebody burning me by using the info somewhere else, so that at least oughta bring me up to Double Whopper status!

Also, in the story I will credit you guys for the mod in whatever way you think is appropriate... and is politically correct for the magazine, of course.

WARNING WILL ROBINSON!

Look close at the two closeup pics to see what happens to the downspout tube at high flow rates, so all of you that have done this may want to trim most the the excess back, leaving just enough to center it in the fenderwell hole. This problem occurred at the maximum flow rate of the housing. It may not occur to a stock truck (see 5.4L theoretical airflow below) but it's probably worth the time to fix it.

The tests were performed by two classes at the University of Northwestern Ohio's High Performance Fuels Class, at their School of High Performance Motorsports, on a Superflow SF-600 flow bench. Each class double checked each result from their class, but each class used a slightly different protocols (both standards in the industry) and I have averaged the results.

NOTE: A 5.4L V8, given 90 percent volumetric efficiency, at 5500 rpm, needs 473 cfm of air. Giving it more than it needs at any given time doesn't necessarily offer any more power. Bear that in mind when reading these results.

Condition/ Average Airflow

1- stock housing & filter, as installed in vehicle- 621 cfm
2- same as #1 but with AEM filter panel- 592.36 cfm
3- stock housing & filter but no silencer or snorkel- 656.83 cfm
4- same as #3 but with AEM panel filter- 632.50 cfm
5- same as #1 but with snorkel tube modification- 597.3
6- same as #5 but with rubber downspout adapter removed- 637.5 cfm
7- same as #5 but with AEM panel filter- 569.51 cfm
8- same as #6 but with AEM filter panel- 619.70 cfm
9- same as #3 but with silencer only- 632.50 cfm
10- Brute Force Intake (for 2004 model)- 733.30 cfm
11- AEM filter only- 1077.25 cfm

You can reach your own conclusion over what this all indicates and I will share mine later if asked

[88Racing]

Originally Posted by Punisher

Does anyone know if these images/vids are available somewhere else now? The links below are no longer valid. I'd like to see the visuals that this thread keeps referring too. I know this was almost a year ago but some of us are just catching up.

Thanks,
-Punisher

That's up to the OP to repost.
Must have gotten lost when the forum crashed.