Nice to see another one of my interests discussed on EE Times.
Indeed, horsepower = torque * revs * a j-factor. So there's no magic in any of this. If you rev the living smithereens out of an engine, you will achieve a high HP figure with small displacement. At the cost of more expensive components, more efficient induction system, noise, and shorter life.
The truly odd aspect of this is that these days, 550 HP is not really considered amazing anymore. Production cars achieve this and more, including the top speed at or close to 200 mph. And production cars can do this with an engine that is just as comfortable driving down the road to the nearest 7-11 store.
And like the article says, if you pressurize the air in the engine, effectively you're increasing the displacement compared to a naturally aspirated engine. For a given amount of HP, though, turbocharging does improve fuel economy to some extent, compared with normally aspirated engines. At least, if you're not demanding that max HP all the time! So we're starting to see more manufacturers offering turbo 4 cylinder engines, and even turbo V-8s, than in the past. I think turbo engines will become commonplace.
There is a tendency for production cars to use smaller displacement engines with turbo charging. I think 300hp from a two liter four with good road manners and fuel economy is just around the corner if not already.
I have often wondered how these engines can run at those speeds and not blow apart. I heard (don't know if it is true) that the engine components are all carefully weighed and balanced for the engine to allow it to run as fast as it does. Can I also assume that these engines don't run for 200K miles? Just thinking about the wear. I would hope that more efficient engines would be possible both through turbo-charging and engine controls (MCU based tuning for performance/power/efficiency).
The fact that these powers can be had is testimony that the technology is there. Obviously those Indy engines don't have to go 200,000 miles but since manufactures of production cars are using some of the techniques it is clear that reliability can be cranked into the equation.
There has been much progress. Turbocharging used to almost certainly result in reduced engine life. Now it is quite reliable.