Gazebo Garden SITL - B3RB Rover Motor Torque Too Low

Hi I am currently creating a rover simulation environment with PX4 SITL in gazebo garden. The rover model is based on Benjamin Perseghetti’s b3rb rover.

Rover model files can be found in here:

Everything kind of works ok but the rover can’t climb steep hills even with %100 throttle power. Speed is not important but I need torque. How can I increase the motor power or torque so that the rover can climb steep hills ?