I can answer your question about airflow and LSD.
LSD is Limited Slip Differential.
None came from the factory but there were a couple of manufacturers that made LSD units for our FWD Transaxles(manual and auto)
1)There is always vacuum in the cylinders.
(Disregarding race engines with valve overlap @ high rpm)
has 0 valve overlap)
2)High pressure always moves to low pressure to equalize.
3)An internal combustion engine always uses up its air supply before its fuel supply.
When the intake valve starts to open the piston is at the top of its stroke and as it moves downward there is a void, low pressure area(vacuum), outside air rushes in to fill the void(equalize pressure).
The internal combustion engine is not efficient and you will never fill the cylinder 100% with air.
Technology has given us Intake Manifold design improvements and Multi-Valve engines with Variable Valve Timing that drastically increase airflow and efficiency increasing horsepower with smaller N/A engines.
That is why today Mom's grocery getter can blow me off the road.
As far a turbocharging.
For the turbo to increase airflow and air pressure in the Manifold it has to be turning fast.
Boost is totally dependent on RPM and exhaust flow past the turbine.
The turbo increases air pressure above atmospheric in the Intake Manifold so more air enters (also more quickly) the cylinder when the intake valve opens.