I wonder how hard it would be to find out directly from nissan themselves what the reasons were for fitting a bov instead of sitting here theorising all day, anyone have any good contacts?
Just for the record I've got a HR31 with the original turbo still fitted (no bov from factory), its run ~12 psi for half its life and the turbo hasn't gone pop yet. ~115kms
That is a load of crap, give one documented example of that happening. Air weighs f**k all, someone worked it out but it was a completely negligible amount, certainly not enough to damage the blades. Put more stress on the bearings/cartridge, yes but how much?