Ive built 3 now using sc12 superchargers, I had a 2T-GEU with a SC12 running around 8 PSI boost blowing into the throttlebody with a bypass valve, Leigh now owns the engine in projects and rides. That had heaps of lowdown torque and went verywell, but is a little noisy with the bypassvalve (plumbback BOV) it is needed to vent the boost on idle and most revs below 2000rpm and the blower intake is open to suck air and will contuine to produce boost against a almost shut throttleplate.
The 4K used 4K-e EFI manifold and was blow thoughthrottlebody too and sufferd from the same noise level and was defected for that reason, but the BOV's where small (person i was building for was a tight ass) and they where not plumbed back. running 10psi, 3-4psi at just off idle and full 10 at 3000ish
Last one is the first 4K-E totaly redsinged and rebilt into a diffrent car (my brothers) that uses the throttlebody on the intake of the blower and you would think is sounded standard, quiet as a mouse :) so no trouble there, it does seem a little laggy down low and really only starts producing boost at 3000ish and only 4 psi and 8-9 around 6500.
pictures etc in rides under supercharged ke70