Great idea, but wrong connection. Detroit Diesel uses this system of Supercharger/ Turbo. I own three of them configured that way, however you can't push air through the Turbo at slow spool speeds because it isn't turning fast enough to handle it. The Turbo will act like a closed valve restricting the flow.
However, if you use the Supercharger to feed air directly into the intake, and use the Turbo to feed the supercharger it will work and work well, if you get the flow rates and tubing sizes right.
At low engine speed, the Supercharger will "come on" early because it's directly linked to the crank speed and will start pumping air. The turbo will come on later [turbo lag] as exhaust pressures increase and exhaust flow increases to "spin" the Turbo faster. The Turbo will then add air flow to the Supercharger.
Superchargers drop efficency as spead increases.. Turbos increase efficency as engine speed increases.. one covers the low end, the other covers the high end.
Good luck.... you will need some to sort it all out.
