What would happen if the formula specified a limit for the power that a PU could deliver rather than a fuel flow limit for engine?
For the sake of this thread, it doesn't really matter what engine formula you apply this to. I just wondered if limiting power would mean that all PU manufacturers would be able to produce a PU that could generate this specified amount of power and then the difference between PUs would be primarily the fuel efficiency (they would also have different power delivery characteristics, etc, but I'm imagining fuel efficiency would be the most import differentiating factor).
Would this lead to a closer formula than a fuel flow limited one or does it amount to the same thing?
Would the PU manufacturers still have an incentive to make the PUs more efficient - surely they would as this is the easiest way for them to get a competitive advantage?
May be it does depend on the engine formula. It seems (from my limited knowledge), that the current formula means that if you have an under-powered ICE you also lose efficiency as well as you get less heat to recover in the MGU-H, so you get penalised twice. May be that is too simplistic.
...oh and I've glossed over how you would measure and enforce a power limited engine formula. I'm sure no one would try to pulse their power delivery to fool the sampling of the FIA sensor.