It had nothing to do with boost or the turbine wheels. Heres the story: I just spent 10 grand and 8 months putting an RB26 into my R32 gtst. I had it on the road for half a day when an oil supply hose to my remote filter popped off the sandwich plate on my block and all the oil was pumped out onto the road. The plain bearings in the turbos seized very quickly, and when the turbos went from 120 000rpm to 0rpm bits of the compressor wheel broke off, went thru the inlet tract and embedded themselves in my brand new pistons. I shut the engine down quickly so i was lucky not to spin bearings or do massive damage to the crank etc. I did, however, almost cry like a baby.
This is my understanding as to what happened; if anyone has a different idea, let me know.