It makes basically no difference on most of these setups. You don't have 6 cylinders worth of air trying to get into the same space at the same time. It's more like 2-3.Originally Posted by Blacknitews6
Just my opinion, but the Z3 crossover looks a little restrictive and not as efficient. The Z7 crossover had separate banks that only merged right at
the turbo inlet. I can see the Z3 is less effective since both banks, all 6 exhaust ports, will actually have to share the same space, in the crossover pipe itself, which can cause the exhaust pulses to hit eachother which will cancel out some of their energy. That might hurt exhaust velocity. I;m sure the Z3 kit will work fine on a mostly
street setup, but i'll always wonder how much more i could make with the Z7 crossover at the same boost level.
Pre turbo exhaust size makes almost no difference.
