Hi Pete,
After speaking to a few guys today in the industry it seems the standard design of the oil feeds aids this problem...its the feed which has the loop in it. A 3mm orifice inside the tube and the bending of this tube that is done on an upgrade (yes i may have contributed in the failure) makes the feed smaller in diameter are two factors involved. Also the oil that sits in the bottom of the loop on shut down gets exposed to a lot of heat (small volume of oil and extreme heat). The question im asking myself is "is this why std rear turbo's always fail"? is the heat and oil starvation to blame as much as the ceramic wheel?.
For years i was a Mobil 1 user...but the last year or so i use Castrol Formula R, and change oil and filter before every meet. Which means the oil would see 500klm tops before changing.
A larger orificed plumbing system in braided line will replace all water and oil feeds and drains with the upgrade (earls will make a killing out of me). I will design and produce the kits for sale after testing to help prevent future failures in other vehicles....how many ppl rip of the turbo's on an upgrade without checking these lines...i know i am guilty of this myself so i can say it would be a lot.
Target is 9's on the low-mounts and with the full interior being installed back in the car, a 9 sec pass will be awesome.