Didn't they say something about pushing that turbo to the limit though?
The EFR7670 turbo is a 64lb/min turbo on its efficiency island which is about 650hp
So they are not pushing that turbo at that power level.
650hp at the crank, assuming no restriction in any other part of the setup. Granted, these dyno numbers are kind of useless without a log or baseline.
I get about 450whp with efr7670 on pump at around 16 psi.