i m usin -5's on my r32 gtr, still 2.6L but forged.. makin 340awkw.. tuned it for response.. i get on full boost at 4000rpm (1.5 bar). but at abt 3000prm, i still get abt 1 bar of boost.. its not too laggy imo. if i sacrifice response, i hit 350+awkw on the dyno.