Veyron engine loses 2,000 hp to waste heat !

[serialk11r]

The reason waste heat is hard to extract is thermodynamics. That waste heat comes out at a much lower temperature, and so it's hard to produce much work from it, especially in a compact package.

BMW's Turbosteamer system is able to recover about 20% of the exhaust stream's heat at lower speeds which is something like a 10% overall increase in efficiency. That's about as much as we can hope for in small engines, a bit over 40% thermal efficiency.

You have to understand that heat energy is much "cheaper" than work (kinetic energy), or electricity, and that it's pretty much not possible to top 60-70% efficiency in a heat engine.

[cRiPpLe_rOoStEr]

Originally Posted by niky

The whole point of the Veyron is to prove VW could make a 1,001 horsepower car that's actually tractable, easy to drive, streetable, and which won't eat its own guts out after thousands of miles of abuse.

No doubt about it. Anyway, if I had one I'd throw a tuned Chevy LS7 with a twin-turbo layout on it instead of overhaul its stock engine

[GRU]

arn't regular engines (in our cars) only 30% efficient, which would mean this Veyron engine is 33% efficient?

[cRiPpLe_rOoStEr]

Originally Posted by GRU

arn't regular engines (in our cars) only 30% efficient, which would mean this Veyron engine is 33% efficient?

And we might remember that, with such a high cost, it could have a more extensive usage of hi-tech ceramic-based materials to reduce internal frictions which lead to all that heat.

[serialk11r]

Originally Posted by GRU

arn't regular engines (in our cars) only 30% efficient, which would mean this Veyron engine is 33% efficient?

Well obviously efficiency depends on speed and load. 33% efficiency at maximum power is *very* high.

At 100% load I know my 1ZZ-FE is most efficient at 3200rpm or so, with a BSFC of 270g/kWh which is about 31% efficiency. Car engines usually have peak BSFC somewhere between 220g/kWh and 250g/kWh. Most of the direct injected engines are peaking around 230g/kWh, which is about 36% thermal efficiency.