nope. i don't get you.
there are 2 turbos.
that eases your spool time, and you don't have lag issues.
keep em stock, get the freer flowing intake, exhaust, downpipe, and you'll get quicker spool time.
there are cheaper way to get that car to spool fast than to go and spend a ton of cash to put a custom supercharger on it...
the skyline, stock, and slightly modded, is more than capable of eating up the cones with minimal lag, if any. and when you're autocrossing, you're usually in lower gears, at high rpms, so you've got no problem keeping the boost up.