new to bracket racing

[Bill Baer]

Originally Posted by bogger01

i see.but how big is too big.like i said i have a small block (357 c.i.) with reworked 040gm heads and a performance cam of an unkown make and size and a factory aluminum intake.i have been told 650 cfm was as big as i could go.any thoughts

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.

[Phillip marvetz]

Originally Posted by Bill Baer

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.