There are two books you should read before you embark on supercharging anything: "Maximun Boost" and "Supercharged." They are both by the same author and are both available through amazon. There is a small section in the book about the 930. It explains that Porsche's decision to use a large turbo(more lag than nessacary, but also more top end power) was for two reasons:
1: these cars are built to fly down the audobaun at top speed and lag is not really an issue when you are doing that kind of driving
2: air cooled engines have trouble sheading heat from prodigious amounts of low-speed boost.
Check out the books, you'll learn more in a night of reading than a lifetime of bench racing.
'74 911 options delete no sunroof. lowered, swaybars, tie bar, braided brake lines, corner balanced, "s" gauges, 993tt seats, Momo wheel and knob, 993 mirrors, blacked out window trim, H4's, short gearing, S pistons, stand alone EFI, other stuff.