I saw you pull into kingsway sports stadium on Sunday arvo and by the sounds of things, one of the problems is your RIDICULOUSLY loud blow-off valve...
When you say you run a 'stock' ecu, is that with any sort of air/fuel controller too? You listed a 'bigger' turbo too, Bigger turbo + Atmo bov on stock ecu is just plain stupid.
How much 'bigger' is this turbo? From what I heard of it the other day, it spools rather early in the rev-range. Just sounds like a stock unit.