Air flow through hood scoop

Wayne Maybury · #1 (**permalink**) 03-12-2004, 08:25 AM

One thing I have often wondered about this subject of air filter size is the following. When a formula is used to calculate the required filter size, is it referring to the size of the opening, that is, the height times the circumference of the filter container OR is it referring to the actual surface area of the filter element which is much greater due to it's flutted shape?

Has anyone ever run their car on the 1/4 mile with and without the air filter? If so, did it make a difference?

Wayne

G-Pete · #2 (**permalink**) 01-05-2012, 05:55 AM

I read this thread from the first to the last post, what I see is a bunch of guys try to explain and calculate fluid dynamics.

What I don't see, are any real numbers - like dyno sheets. With or without turkey pan / larger or smaller filter.

To bust some of the bubbles here, the efficiency of an air filter is altered by 25% in the first 6 month (not in Nevada or West Texas - more like 35%).

Many numbers swirling around about CFM and RPM. All manufacture numbers are based on a stoichiometric air–fuel mixture. Well, most carburetor guys just can dream of it. So, take 25% of the number and let this the base of the calculations.

A good motor performance is not created on the internet nor just on paper. Many "internet engineers" don't realize that. They even believe Wikipedia is correct in all fields.

Trial and error is the key, so if someone would provide some numbers here to make this thread more substantial.

Thanks

davids2toys · #3 (**permalink**) 01-05-2012, 08:24 AM

I agree with you to a point, but as a start in the right direction, the airflow is what it is. So if my K+N filter wont flow more than 450 cfm brand new(per K+N tech dept), and engine needs 750cfm to perform to its intended potential, at this point it is not rocket science!
I love the look of the turkey pan and I have the biggest filter (height and width) I could possibly run with the turkey pan. I will be going with the spiral flow exhaust this year which will flow much more than my present setup, this will further exaggerate the starving for air in high performance situations. I will most probably go to a cool looking ram-box setup and a dyno service to get it all perfect!
Dave