And for anyone debating between a helical (Quaife) vs. a clutch type lsd (OS Giken) for an autox build, let this be all the evidence you need to go clutch type. If you listen to the engine noise, you can hear my diff (Quaife) opening at various spots on course due to unloading the rear inside wheel.
I'll be replacing my Quaife with an OS Giken during the off season because it's become such an issue.