I can hear a crunching sound when turning R and using throttle. I hear it whether or not the car is on the ground. I can hold it and hear the sound.
Sounds like something in the gears up front but why only R turn?
You may want to check the drive train without the motor. Does it make that sound still? If so, check the pinion and outdrive gears in the differential. They have some slop in them and seem to be a failing point in that area if not shimmed.