A proper LSD to replace the clapped out viscous unit. As I would get into boost it would break one tire free before the other resulting in a massive lunge to which ever side broke loose first. Admittedly I almost wrecked it on the highway one cold wet night in GA when I barely dipped into boost in 5th gear at about 70mph(NA subframe)- the car broke loose exactly as you describe with very little warning. I thought it was an improper alignment at first but had a couple different shops easily get the alignment into proper spec. After installing the Nismo clutch type unit I can hold it straight very easily when the tires spin no matter the speed. If you need a good diff builder local to Atlanta shoot me an email. He can replace the viscous unit and carrier bearings pretty cheaply and leave the pinion bearing alone(saves A LOT of $) as long as your pinion bearing isn't shot.
