IS THERE A FORMULA FOR CARB SIZE?

Old 05-06-2011, 09:13 AM
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JEFF69Z28
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Default IS THERE A FORMULA FOR CARB SIZE?

I HAVE A LITTLE MORE COMPRESSION AND A DIFFERNT CAM THAN I HAD LAST YEAR AND THE MOTOR STUTTERS WHEN I LEAVE THE LINE I WAS WONDERING IF I WAS UNDER CARBED.
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Old 05-06-2011, 10:48 AM
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Scooterz
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You can run the basics on a common chart by Holley if I remember correctly. It has been awhile since iv'e done it, but I think it was like cubic inches by max RPM ... then it gives you a starting point. from there, it will help fine tune the size needed.
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Old 05-06-2011, 10:50 AM
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fast75vega
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tci carb calculator

http://www.tciauto.com/Content/Stati...ieSupport=1#13
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Old 05-06-2011, 07:47 PM
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TheYellaBrick
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OOOoooo. nice bunch of formulas !! THANKS !!
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Old 05-07-2011, 06:13 AM
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TheRabbit
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All the racing math you'll need.
http://www.wallaceracing.com/Calculators.htm

BTW
Air Capacity & Volumetric Efficiency

Theoretical cfm = rpm x displacement / 3456
Volumetric efficiency = actual cfm / theoretical cfm x 100
Street carb cfm = rpm x displacement / 3456 x 0.85
Racing carb cfm = rpm x displacement / 3456 x 1.1

I made some of my own Excel spread sheets for carb. size and for gear ratios and tire speed with any transmission and transfer case / chain drive.
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Old 05-07-2011, 07:04 AM
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fast75vega
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Originally Posted by DrivingMissDD
OOOoooo. nice bunch of formulas !! THANKS !!
i know i tried them all with our 3 cars(which are all setup differently) and they are all damn near right on the money :wink:
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