Mort

The G80 is not a high performance differential. It is meant to increase traction at low speeds and in slippery conditions and to work as an open differential the rest of the time. It engages when a speed difference of 100 rpm is sensed between the rear wheels. It does a good job when it is used as intended. A lot of people have discovered the shortcomings of the G80 in a high performance setting.

I am not sure why it would disengage in a burnout box at the track but I am sure that is beyond its intended abilities. Maybe it never gets a chance to fully engage under those types of conditions or perhaps the torque being applied is enough to kick it out for some reason. I guess wear could be a factor for it disengaging in the burnout box. I am not really sure what parameters make them disengage just that there is a pawl or cam that keeps them from engaging above 20 mph if they are working properly. AFAIK that pawl does not do anything if the diff is already locked up.

Mine works seemlessly and I never feel it engage or disengage. So far when I have abused it I get two black marks that seems to begin and end at the same time. I have spun mine through the 1-2 shift and it seemed to stay engaged through the shift because I got two marks before and after the shift with about a 30' break between the marks.

They do love to disintegrate in tight corners when they are locked up on high traction surfaces such as dry pavement.