Overbore and polish the throttle body look into a J's racing or Password intake, get some stage two cams( crower makes some decent ones ) unorthodox pullies and a nice exhuast...i think you got a nice little bump up in speed there. Maybe a bigger fuel rail, intake manifold and some injectors, reprogramed ECU...lots of s stuff. somewhat cheap compared to a turbo...all together you prolly got yourself about as much for a turbo though =P

Some companies make better junk then others...make sure u check into that too