I read (I think it was n here?) that GTR's do run the ceramic turbos. Harry (L18_B110) bought one for a race car, and I'm sure someone said that you couldn't boost them over XXXpsi as the turbo's could fail.

yes gtrs use ceramic turbos, not in N1 spec from memory

gtr forum uk about ceramic turbos
wiki gtr info
The first model of the N1 engine was the R32 N1 engine. It uses a pair of larger turbochargers compared to the standard R32 GT-R. The turbine wheels on the new turbochargers are made from steel, rather than the weaker ceramic used for all standard GT-R models. The R33 N1 engine was slightly revised, with larger turbochargers than the R32 N1 engine, supporting more power if the engine were to be modified.

The R34 N1 engine saw further improvement. The camshafts were slightly improved for even more potential power, the turbochargers were about the same size as the R32 N1 turbochargers, except now they use ball bearing technology, which operates much more quickly than any other model used.