the GTS4s share the ATTESSA system with the GTRs. Have a look at
www.advan.co.nz - their demo GTR began life as a GTS4, until they grafted on GTR body parts, and stuck in a 700hp (or something) RB26DETT (and interior stuff and whatever else, I'm sure...dunno everything they did) . Some people will argue endlessly about whether it's a GTR or not, but in the end it doesn't really matter, IMO.