Nissan wanted to do a turbo GTS but didn't for a lot of reasons that are still unclear, stuff like they wouldn't produce it without an intercooler, but having one would have driven the development and sale costs too high, Nissan engineers wouldn't approve them without 5 stud hubs, etc etc, though I personally don't believe the 5 stud hub one
There was a concept prototype Silhouette GTS with an intercooled RB30ET that ran something like 200kw/400Nm and a flat 14 second 1/4 mile, which was awesome for 1987/88 6 cylinder