You can fix the revving by putting a restrictor in the
IAC valve line. Did it to mine and it was so much nicer to drive.
_2:
Mine went quite well, quicker than V6 Commondoors from the lights and excellent for overtaking in the country without changing down gears. The engine was the best part about my ST24. I did have a pod filter fitted, which I took off just before selling and it did feel like it had less power.
BTW Motor (or Wheels?) managed a 15.7 second 1/4 mile when they were first released from a stocker. Perhaps that one is shagged?