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Old 12-25-2009, 08:14 PM   #30 (permalink)
RCZ
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umm.... its all about compression. The STI has much lower compression than the Z because the STI is turbo from the factory and thats one way to make turbo cars safer. Lower compression engines need higher boost to achieve the same amount of power. A stock sti runs around 17psi. My built STI ran 25psi on a big turbo all day long. Some supras out there run 35 psi and some old turbo F1 cars ran upwards of 5 BAR, which is more than 60 PSI. (made 1200hp from a 1.3L motor)

So you aren't going to get flamed.

The Z has a higher compression engine because it is originally NA and thus it needs less boost to make power. Its not exactly the greatest idea to boost a high compression engine because theres greater stress on the internals, however it can be done safely. From what I've been reading the stock VQ37 can handle around 6psi. The other thing you have to keep in mind is the size of the turbo in relation to its efficiency zone. A big turbo will have a much easier time making 20psi than a smaller turbo will. When a turbo goes beyond it's efficiency zone, it starts blowing very hot air which is not a good thing for making power or for engine longevity. I'm not going to go into CFM and flow volume, but thats also part of the equation.

Anyway, no there aren't any VQ37 Z's running 20psi because as far as I know, no one has modified internals to lower the compression. 20psi on a stock 370z = 1000rwhp+ for like 2 seconds before it blows itself to pieces.
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