At this point though they loose their efficiency, what is going to limit you on boost is injector size. does your car currently have a remapped ecu? if it does not, I would not run 14 psi without the remapped ecu for the 370cc injectors. if you already have the 740cc injectors ready to install and have prepaid for the ecu from specialty z why would you not put them in. then you would have absolutely no problem, at that point the injectors will flow way more, and you could max the turbos out if you really wanted to.