Best thing to do for this post is do a search. This has been driven to the ground on this forum many times but here are some fast answers:
1) Supercharger - belt driven
Turbo Charger - exhaust driven
2) There are lots of pros and cons for both please do a search on them. In a nutshell
SC- Pro: no lag and linear power curve
Con: Puts load on the engine since it's driven by belt. Cannot adjust PSI on the fly
Turbo- Pro: Very effecient, uses exhaust gases to drive turbine. Can adjust PSI on the fly.
Con: Boost lag, takes the engine a certain RPM until the full tubine kicks in.
Why do you need Twin Turbo setup: The G35 is a V6 and it is generally easier to twin turbo a V6. Since the engine is in a V shape, the placement of turbos on each side of the V as shown oVo
doesn't take a lot of complex piping to achieve this.
But you don't need a twin turbo setup. It's just easier...
You can also single turbo a V6, but it will take a lot of piping to do this to connect all six exhaust outlets to the single turbo. Plus looking at our limited space in the G35 engine bay, it's not very easy.
- Don't argue with idiots. They will bring you down to their level and beat you with experience.=P-