What was found
DURING CLIMB TO CRUISE, PASSING THROUGH 6000 TO 8000 FT THE ENGINE ITT WAS AT 740, WITH THE POWER BEING SET AT ONLY 1200LBS OF TORQUE. WE WERE ONLY ABLE TO MAINTAIN CLIMB RATE OF 200-300 FPM WITH AIRSPEED AT 95-100 INDICATED KNOTS. AT CRUISE ALTITUDE OF 8000FT DURING THE ENGINE TREND MONITORING TEST, AT 700 ITT THE TORQUE DROPPED INITIALLY TO 900LBS AND EVENTUALLY STABILIZED JUST UNDER 1000 LBS OF TORQUE. OAT AT 8000 WAS 24C OR76F DEGREES. DUE TO THE AIRCRAFT UNABLE TO PERFORM AT THE SPEEDS AND MAINTAIN PROPER POWER SETTINGS LISTED IN THE POH I AND THE FIRST OFFICER DID NOT FEEL COMFORTABLE WITH CONTINUING THE FLIGHT TO DFW WHICH WAS 2 HOURS AWAY DUE TO AIRCRAFT UNDER PERFORMANCE AND STRONG HEADWINDS. HRO WAS ONLY 20 MINS AWAY WITH THE TAIL WIND. WE INFORMED ATC OF OUR INTENTIONS AND RETURNED TO HRO AND LANDED SAFELY.