Prodigy is claiming 506whp with their new Challenger 3.6L twin turbo kit.
Not sure if the Challenger's 8speed auto has any more than 20% drivetrain loss, but that would make it 600hp at the crank.
Yeah that is amazing. Stock engine too. I plan on doing a single turbo on stock engine. The 8spd w/ a 2 piece drive shaft into a independent rear diff. will rob more power than your drivetrain and my fwd set up.