Well, I haven't done this yet, but you can re-tune your carbs. Supposivly you need to do that every 6 months on a dialy driver. That will make sure that one carb is not running more rich than the other. Also, the proper mixture will add more power. Running too much fuel takes away power. Another thing you can do is swap out your distributor for an electronic distributor from a 1981-83 280zx non-turbo. Put on a little bit higher powered coil. That will give you some nice spark. Be sure to put in spark plugs for a 280zx also. Those plugs will be made to burn hotter. After that simple and not too costly upgrade, you can see if you like the Z as it is.