The pistons are with ACL at the moment being tested - In the experience of several of our customers (who have come to visit!) we are all in agreeence that the piston simply pulled apart at the gudgeon pin. This is common for overrev's or simply overpowered piston. Track racing the car on cast pistons with 400kw, i tend to believe overpowered. Plus the twin electronic throttle system and electronic gearbox make an overrev impossible! It doesnt let you select the gear if it will rev too high, and on downshift it opens the clutch until its safe! amazing!
I read this in the nissan blurb too - but in the same blurb it also states forged pistons.... Im no expert on the rods, but these look and feel just like any other nissan rods i have seen..
As for the oil, it was using the reccomended mobil oil. And I agree with you about viscosity for many engines. And also believe that a lot of people are using oil that is way too thin for clapped out "race" motors in the australian climate. But the newer close tolerence variable cam engines normally need to run pretty much the same oil that is reccomended.
As for the gearbox - we are ontop of that too. Heaps of GTR first gears already breaking and already seeing a gearbox with under 10 launches get crack tested to see that its ready to go its time for a full gearset in ours as well.