GM Tuners didn't do that flowbench testing. They 'borrowed' it from another source. Nevertheless, that flowbench data is somewhat useless. It simply states how much a TB CAN pull with and without a MAF screen. Not how much it DOES on a particular application. If you can't outflow the numbers tested with the MAF screen in, there isn't alot of point other than response.

Thanks for the lesson on velocity and laminar I guess by your answer if a '92-'93 L67'* rotors were coated it should? would? be faster then a '94-'95 L67 because the TB'* and cases have a smaller diameter inlets on the '92-'93'*. I could agree with you if we were talking N/A or if you are talking about some extreme case - but we are not. We are talking about a roots type blower - every revolution it wants to move an x amount of air. Making it easier to pull air in makes the blowers job easier. Right? :? So wouldn't a large diameter short intake be easier to pull air in then lets say a smaller diameter long intake? :?

I'll answer your question with two more:

What flows better? A stock airbox with a drop-in performance filter, or a custom intake with cone filter?

Why?

Are you following this or are you lost? Is that not what I said? The one with less of a restriction will flow better.

I'm taking about you saying that a 3" intake will out perform a 4" intake. Come on?

Again, just like hogging out ports, many think bigger is better. A 4" intake may slow down the car because it exceeds the velocity limts in the intake trac. When it reaches the TB, it gets restricted by the throttle blade angle. The excess air cannot go anywhere. Creates a wall that kills and slows down the velocity, and it will also create reversion pulling the air the opposite way.

Have you ever heard the term "Venturi Effect". The venturi effect theory is used on race exhaust headers merged collectors to improve exhaust scavenging in which they neck down the exhaust collectors. The same principle is used with carburetors. Air passing through an hourglass-shaped venturi accelerates as it passes through the narrowest part of the venturi then slows down and expands as it emerges on the other side. This expansion creates a pressure drop, in effect siphoning air into the low-pressure side of the venturi and drawing more volume through the venturi.

So, can you see the picture.

For the record I still run with the MAF screen in.

Ummm..... Sorry, but No, on both counts.

Race headers use the pulses from each exhaust stroke, timed, by the length of the tube,
not a venturi effect, to scavenge the exhaust. ( i.e. a "Tuned" header)

Necked down "collectors" would add .......a restriction, and a build up
of back pressure, and subsequent reduction in flow.

.....Let 500 cars thru 100 toll booths........... = no traffic backup
.....Let 500 cars thru a single toll booth ......... = big traffic backup.

The speed of the fluid increases, not the volume.
Bernoulli'* law states as pressure decreases, speed increases. and vice versa.
You won't increase volume. (IOW you can't get something for nothing.)

Try it yourself...

http://hyperphysics.phy-astr.gsu.edu/hbase/pber.html


In a carburator, the venturi is siphoning fuel, not air.
( i.e. Something else is added to increase the total volume flow.)
Reducing the tube size (with a venturi ) makes the flow faster, but at a lower pressure, and not in greater volume.

For greater volume, the fluid (air) would need to be compressed... hence the addition
of super chargers, and turbo chargers........

(And they said my staying in school was a waste of time... )

Forced induction increases density, decreasing the volume of a certain mass of air to fit into a certain space.

I'll answer that... But your question compares apples to oranges.

Firstly, you flow faster, not more in a smaller diameter,
because, ( Mr. Bernoulli, and his Venturi again.... ) as speed increases.... pressure drops, decreasing volume.

10 cars @ 50 MPH, or 10 cars at 90 MPH is still 10 cars. ( the pressure equivalent here would be elapsed time )
Cars moving faster , yes. .....More cars...no.

It is the custom intake with cone filter, that flows more efficiently.
..........Because of the laws of nature.
It'* kind of like saying "which is easier to walk thru an empty hallway,
or one crowded with people.."?

Stock intake has restrictions : inlet area , baffles, and the big killer...
turbulence, from the accordian style connector.
Custom intake with cone filter, eliminates these restrictions. Large inlet, no baffles, no accordian.
It also supplies a denser flow (cooler= more per volume unit) of air.
Of course it flows "better".

But.......... not necessarily at a greater volume, in any given instance.
It'* volume depends on the ratio of ambient pressure density, to manifold pressure density.
The greater the difference the larger the flow. Again... the reason for */c'*,
is to increase this ratio.

But this doesn't address the question of flow volume and pressure that the
larger/smaller pipe would exhibit, under normally aspirated conditions.
Given the same unobstructed pipe design , a larger pipe would flow more volume at
the same (atmospheric) pressure as a smaller pipe.
Or, if the volume were constant, the larger pipe would flow at a lower pressure.

Otherwise, by your intimation, instead of large diameter exhausts, people would be running soda straw size exhaust pipes, and restricting intake, for better flow..

I'm with "llBlazin_llLo" on this one.

Absolutely!

Now that you have decreased the volume, for the sake of argument.. by half...
You can now "fit" twice as much in the same given space, at the same time.
That... equates to an increase in volume flow!

If you take a sponges measuring 2x2x2, and compress them into cubes 1x1x1,
how many cubes of the 1x1x1, will fit in the volume of the original at the same time?
Answer = 8 cubes (or a compression ratio of 8 - 1)
That'* an increase in volume x 8.