Increasing efficiency on head ports/intake manifold/exhaust manifold will increase the performance on these parts you can go above 1.0, it's why the carb intakes and carbs work better from the blackseries parts compared to the base intake manifolds and fuel rails, fuel rails also have their own settings for fuel consumption and such that I haven't started messing with but adding fuel to the consumption parts and having high intake efficiency lets you run some massive boost.
