Why did VF stop at the 570 kit? Would be nice if they offered a "race" Stage3 kit!
Based on HPF's turbo data, they seem to be able to push 600whp on stock internals (granted better gas than 91 octane):
LHD Stage 2 Dyno
91 Octane (518hp)
91 Oct + Alc (670hp)
110 Octane (731hp)
110 Oct + Alc (762hp)
Multiply by 0.82 for rwhp
60-130mph in 6.86 sec
Factory Internals
It would seem that VF could go one more step further, perhaps a VF670 kit which requires meth or race fuel at the minimum (perhaps 12-14psi?).