Looking Great
You say so still spin up the wheels, I assume this is mostly in first gear and perhaps a bit in second also? Just wondering because my car has huge grip from only 225/45/16 semi slicks, always surprises experienced tuners/drivers by just how well it grips once the tyres are warm so for sure Z's can grip. Softish rear suspension helps it squat a bit and dig in. On cold tyres it will spin second even on low boost but once they are warm the grip is great, not to much spinning even on high boost, first gear is always useless though, I would imagine if I ran 315's I would get zero wheel spin in any gear, although I do only have 480hp 500ftlb for now.