SMALLER WHEELS definitely. You're slowing yourself down and limiting your car's true speed potential with such a ridiculously sized wheel for an ITR. Clutch, because stock clutch is desiged to barely handle anything more than 160hp. EMS, and a damned good one too, some dyno tuning.

After you're done with those it's time to work on the ITR's strongest point: handling. So lots and lots of PROPER suspension work is next in line after that.