You can try adjusting your sway bars to see if that helps. Put the front on the softest or loosest setting and the rear on the stiffest. If you had adjustable dampers you could also tune those to your driving style; or if you had adjustable front upper arms you could dial in more negative camber in the front tires to give you a little more grip in turns. Next time you could also run a little wider tire in front, like a 255/40/17 or 265/40/17. The 300zx is naturally more prone to understeer because it is a few hundred pounds heavier in the front than the rear, on my car its like 2000 lbs front, 1650 rear with me in it, (55/45 weight distribution), but you can dial out the understeer with suspension tuning. Just a few ideas.
