pipe cross section formula

specops_SC

Registered User
does anyone have the formula for figuring out the cross sectional area of a certain diameter pipe? im trying to figure out what size to make the middle section for best flow if i use two 2.25 in pipes from the manifolds. thanks..

Moses
 
specops_SC said:
does anyone have the formula for figuring out the cross sectional area of a certain diameter pipe? im trying to figure out what size to make the middle section for best flow if i use two 2.25 in pipes from the manifolds. thanks..

Moses

You might want to check the following link, as it gives some numbers for area in respect to pipe diameter.

http://www.sccoa.com/forums/showthread.php?t=31591

Read the entire thread, as a correction was made.

I'm setting up a custom exhaust for my '90 and I'm going with 2 1/4's into a magnaflow resonator with a 3" exit. I'm trying to make things flow better, but give a bit of back pressure so I don't loose my bottom end torque.

Hope this helps

Frit
 
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fturner said:
You might want to check the following link, as it gives some numbers for area in respect to pipe diameter.

http://www.sccoa.com/forums/showthread.php?t=31591

Read the entire thread, as a correction was made.

I'm setting up a custom exhaust for my '90 and I'm going with 2 1/4's into a magnaflow resonator with a 3" exit. I'm trying to make things flow better, but give a bit of back pressure so I don't loose my bottom end torque.

Hope this helps

Frit

the link didnt work. said i had insufficient priviliges :confused:

Moses
 
3.14*(diameter/2)^2 = cross-sectional area of a circle.

Basically, divide the inside diameter by two (radius), multiply that number by itself (square it), then multipy by 3.14 (pi).

Hope that helps.

-Rod

EDIT: Here's an example, using 2.25" i.d. pipe:

2.25/2 = 1.125

1.125 * 1.125 = 1.266

1.266 * 3.14 = 3.974 = cross-sectional area of one 2.25" i.d. pipe.

So, two 2.25" i.d. pipes have close to the same cross-sectional area as a single pipe with a 3.12" i.d.
 
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racecougar said:
3.14*(diameter/2)^2 = cross-sectional area of a circle.

Basically, divide the inside diameter by two (radius), multiply that number by itself (square it), then multipy by 3.14 (pi).

Hope that helps.

-Rod

EDIT: Here's an example, using 2.25" i.d. pipe:

2.25/2 = 1.125

1.125 * 1.125 = 1.266

1.266 * 3.14 = 3.974 = cross-sectional area of one 2.25" i.d. pipe.

So, two 2.25" i.d. pipes have close to the same cross-sectional area as a single pipe with a 3.12" i.d.

all right. been a little while since school. :rolleyes: not that i payed much attention anyways. i'd be reading hot rod. :D
 
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