There still seems to be alot of different opinions in relation to series 1 vs series 2 turbos....
As i have stated before, my new S2 has both steel wheels and BB. When i put it in for high flowing i was told this was quite common on the ones done before to be steel. Maby Nissan put out a years worth with steel wheels, or maby boy racers in japan had them all changed. I was told tho, with the steelies that they loose a bit of puff down low, but pull harder than a plastic or ceramic wheel. Steelies are good to about 13/14psi safe with intercooler and rest of the mods to match. Could push 16psi in the right hands, with some extra work. ie. High flowing, Power FC tuned to perfection, living in sub zero temp's could help also....