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Old 10-27-2011, 12:12 PM   #2
Phillip marvetz
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Default Re: new to bracket racing

Quote:
Originally Posted by Bill Baer View Post
There is a formula :Racing carb cfm = rpm x displacement / 3456 x 1.1 so it depends on how high your going to twist it @ 7000 RPM it comes out 795CFM so I would use a 750 the vacumn secondary (3310) being the easist to live with on a street car of the double pumper for race use only.
Now if you do the math an spin it 10000 RPm you need about 1136 CFM and in that case a tunnel ram and two carbs would be the ticket.
Note there are a lot of other varibles to be considered cam size ignition timing (intial lead and curve speed) collector length and torque converter stall and keep in mind that formula is for a dedicated race car.
The street formula is Street carb cfm = rpm x displacement / 3456 x 0.85.
Hope this helps.
That is fine for a street car, If you want a bracket car that will repeat the 850dp is the way to go.
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