IMO at least a 20g if not something a little bigger.
Talk to the Tuner who will tune the car. That's the best info you'll get.
210,000miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. CHECK your oil, these cars use it.
Engine Build - Click Here