Same as what Ash said 12 Psi = +0.8 Bar, +0.1 bar over standard.
Don't push the Ceramic turbos too hard.
R32, 33 or 34 GTR's, either way they will have to be rebuilt or replaced.
These cars from Japan are not treated as nicely as you think.
If you want a R32, just be prepared to fix things.
If you want a R33, just be prepared to fix things, maybe a year or 2 later.
Same goes for the R34.