PT-6 Torque Limiting
To quote for another thread, " if i see Speed decreasing and a building coming up my flight path, "I" would put the Thottles ( Presumed both Donkeys working) to the Forward Stop. This will provide 2450ft/lb instead of 2230ft/lb Torque. There is a Limiter in the FCU set to this Value, you wont blow the Engine. But of course afterwards it is getting expensive".
I seem to remember an overspeed governor and perhaps a Fuel Topping governor on the PT-6. Is this what limits the torque to a certain value?