yeah i spoke to a guy yesterday and man he broke it down for me big time he went very scientific..lol here is his formula he showed me for my 454
Principle items in baseline carb CFM calculation are displacement and RPM. Secondary factors are volumetric efficiency and intake manifold efficiency (manifold factor--MF. MF ranges from about 1.1 for a racing manifold to about 1.5 for a poor-flowing stocker.) 3456 is a constant that accounts for the number of cubic inches in a cubic foot; and the fact that this engine has a four stroke cycle.
Cubic inches X RPM / 3456 X VE X MF = baseline carb CFM requirement
454 X 4000 = 2270000
2270000 / 3456 = 656.83
656.83X .75 (projected VE) = 492.62
492.62 X 1.4 (projected manifold factor) = 690 (rounded) CFM
so he told me a jetted 670 a 700 or a 750. he told me to get the 750 to play it safe and i can always jet it down. he really broke it down for me big time. after doing my camaro calculation we came up with 647 rounded CFM so he told me we need to play with the jetting on the 650 thats on it now
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2005 dodge magnum daily driver
1988 mazda rx7 LS6 swap
1969 SS work in progress
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