Setup gearing (start -1 front and +2 back) get some decent tires on it, the standard bridgestones are street tires and i like them as my street tires. Don't know if yours is a FP or a limited us spec, mine is a EU FP spec and even mine has a poor grund power, rip of the cat and add a link pipe. Even with the stock can and a link pipe it will feel stronger. I can't imagine the G4 will handle like a bus, mine handles like a bike.
Things i did -2 front, steel brakelines, RCS brembo MC, cat delete pipe and sinds last week the MIVV GP can (until last week i ran the stock can) and for track i use bridgestone or pirelli slicks. My supsension is still stock for the moment.