Just found this:

"(CID X RPM divided by 3456) X (BOOST divided by 14.7 + 1)
You have to treat this as two calculations. Take a 350 Chevy turning 6,000 and stuffing 8 lbs into it for example:
350 times 6,000 divided by 3456 = 607 CFM
8 divided by 14.7 = .54
Add a 1 in front of the .54 to reach 1.54
Multiply 1.54 times 607 and find that the cfm required will be 934 CFM. "

(250x5500/3456) x (6/14.7 +1) = 557 CFM.

Actually your carb is the right size assuming 6psi boost. Note: vacuum secondary carbs don't work for turbos. You'll never open the secondary because you'll never have vacuum there.

Another website said you'll likely see 350 hp at the crank at 6psi. That should really make her scoot! Looking forward to seeing the video when it's done.

I'm new to the idea of turbo charging. Where does one get vacuum for the brake booster and vac advance? Weld a bung before the turbo in the inlet piping?

Last edited by gbauer; 12/09/15 12:22 PM.