GT Motorsports: 370Z Supercharger system development

Originally Posted by RCZ

Alright so after reading a bit from reputable sources. AKA Garrett from the stuff that Silo showed us.

Bigger turbos make more power per the same psi for two main reasons:

1) Bigger turbo will put less heat into the air and therefore the air is denser. More air = more power

2) The actual CFM of the turbo is meaningless. What matters is how much of that air is actually going into the engine and being used. There are restrictions that keep all the air from getting to the combustion chamber, the main one being backpressure from the exhaust housing of the turbo. The smaller it is the more backpressure, the less air that can flow through the engine, the less air that can flow INTO it in the first place and therefore less power. So bigger exhaust housing means less backpressure, meaning more air in, meaning more power.
The logic seems to be that it doesnt matter if the turbo can flow an infinite cfm, if the engine can't make use of it. The less backpressure, the more the engine can use, the more power it can make.

So how does this all apply to the SC vs TC dilemma?

I would say its the same thing, more flow through the engine means more power. So why do manufacturers recommend sticking with 2.5" piping rather than 3" piping on an SC? Because the sc doesnt flow enough in the first place to cause a 2.5" exhaust to become an obstruction??