Its an engine dyno as well. Crank HP. I'm curious to see how this comes out.
My logical side says they dyno it right above the 470HP as advertised, but......
Doesn't that also show there isn't barley any loss of hp to the wheels when its normally 15%. At a 15% loss there would be only 403 going to the wheels on the Challenger 392, there were proven dynos with 452rwhp, at a 15% loss that would be approx 521 hp at the crank. Since this dyno shows only 475 at the crank than that shows only a 5% loss.
More than likely it's the difference between an inertial dyno like a Dynojet vs. a proper brake dyno. On the Dynojet's they have a formula that "simulates" BHP (Brake HP) as a function of acceleration (how fast you can accelerate a known mass). That formula is a bone of contention between Dyno makers. Put that same Challenger on an eddy current brake dyno and HOLD 6000 RPM and I think you'll see an entirely different result. BTW, all dyno's measure is torque, it's the software that turns it into HP.
There's always more to be had, the trick is doing it in a way that doesn't destroy the longevity and reliability. Manufacturers live by a different set of rules than the aftermarket so I suspect this IS the most you are going to get out of this motor under the "rules" the manufacturer is required to play by.
Is this the most we will see once the ECM is broken and engine builders take a crack at it, of course not, but I would bet that gains past a certain point will mean big dollar engine failures that most people simply aren't willing to risk in their street car