6-71 BDS Supercharger Basics
Okay! I'm presently working on a Blown Mouse-Motor buildup and have purchased the forged bottom end required for this venture. Forged as in crank, rods, and inverted dome blower/nos pistons. The specifics are purposely left out now because my question involves the forced induction.
I have a 6-71 BDS Supercharger that has been modified and clearanced for street gas usage with double pinning, .007 rotor clearance, and no Teflon. My choice there. All new bearings and gears. A new 3 7/8 inch snout. Now comes my dilemma. The drive pulleys. I'v decided to run a 3 inch belt at 1/2 inch spacing. I prefer this old school over the 8mm. Really, for street, it doesn't really make much difference. Determining my under drive is fairly straight forward and yet I'm baffled.
My question: For this street buildup to work, I need to determine my boost. At 93 octane pump gas availability, I want to keep the boost at approx. 7 to 8 lbs max. There are so many factors at work here with head cc's, stroke, compression, cam, and on and on. What I need is a rough idea of the way to calculate boost based on the drive pulley teeth and/or ratio with this 6-71. Any ideas???? Can I base it on % underdrive?