How much I am leaving on the table?
With some basic calculations, you can take the cross sectional area (r= 0.9375" for the 1 7/8" and 0.875" for the 1 3/4" headers, already a heafy difference when dealing with squares).
1 7/8": Pi*r^2 -> 3.14159*0.9375^2 = 2.76116sq.in. of area per tube.
Then you multiply this by the 'height' of the cylinder, or in this scenario, its length to get the volume, which should be 24" in a long tube header.
2.76116sq.in.*24in = 66.26784cubic inches, per tube; multiply that out by 8 primaries and you get:
66.26784cubic inches * 8 primary tubes = 530.14272cubic inches of volume in your exhaust headers.
1 3/4": Pi*r^2 -> 3.14159*0.875^2= 2.40527sq.in. of area per tube.
Then you multiply this by the 'height' of the cylinder, or in this senario, its length to get the volume, which should be 24" in a long tube header.
2.40527sq.in.*24in =57.72648cubic inches per tube, multiplying that by 8 primaries and you get:
57.72648cubic inches * 8 = 461.81184 cubic inches of volume in your exhaust headers.
Good debate.



