decent torque for a n/a 2.0L....
you can see that the engine just dies above about 5800...the biggest gain would probably come from opening up the breathing up there. that would help it to keep making torque at higher rpms, which is what makes real power. id' be interested to see a dyno with an intake, decent headers, and a less-restrictive exhaust. although i suspect the head itself is a big limitation as well.
that's why the celica engine makes that much power...it only makes 125 ft-lbs, but it makes that all the way up through the rev range.