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Originally Posted by kane66
For all those people representing metro's. Found a Turbine engine mounted to a metro torque converter and auto transmission. 100 hp. and only weighs 68lbs. From what I've read turbine engines are 60% efficient, as apposed to ICE's 30%. It's a lot of money to double your FE but it would be awesome.
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Keep in mind that, while the efficiency of gas turbines climbs with practically each passing day, older gas turbines tend to be EXTREMELY inefficient. And I would be willing to bet that what we are looking at here is hardly state of the art.
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Originally Posted by Big Dave
I Don't Believe It
Gas turbines only surpass ICE's after they pass the 100,000 HP level - what turbine people call Frame 8s. That little heat loss thing, y'know.
It might fit, and it would probably go like a scalded dog. But like the Hyabusa engine in a Smart it would get lousy MPG.
Did you ever stop and ask why - in a hypercompetitive auto market - nobody ever offered a turbine?
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Actually, there is a REALLY good reason why automakers aren't offering a turbine - cost. Not only are there hefty costs when it comes to developing the things. But turbines are also VERY expensive to build. Although they have FAR fewer moving parts than an ICE (and by the way, a turbine actually IS an internal combustion engine!), the parts themselves must be manufactured to VERY exacting tolerances, and out of highly expensive heat-resistant materials. Add to this the fact that a truly efficient turbine would likely be of the more expensive axial flow design (as opposed to cheaper and less efficient centrifugal designs), and you can see that it would be virtually impossible to build a cost effective turbine - at least any time soon. Anyway, the automakers currently have all bets on fuel cells (and NOT turbines) for future automotive propulsion. So I would not expect to see any turbines.
As for the 100000HP threshhold, this is not the barrier that you make it out to be. For instance, Capstone Turbines (a manufacturer of microturbines) currently has a 200HP gas turbine on the market for electrical power generation with an ELECTRICAL efficiency of around 33%, or probably about 36-38% efficiency at the power take off! Their 60HP version has an electrical efficiency of 28%, or about 32-33% at the shaft. True, neither is 50-60% efficient. But both are still well in excess of what is possible with a conventional gasoline engine. In fact, the 200HP unit is well within the range of diesel efficiency. Of course, compared to a diesel, it will burn MUCH cleaner, run MUCH smoother, and require MUCH less maintenance. It would also be able to run on a VERY wide variety of different fuel.
Another interesting microturbine is the Wilson microturbine. It is still somewhat in the research stage. But with its special heat exchanger, mostly axial-flow design, and ceramic turbine blades, this turbine promises an efficiency of 55% at the shaft, or 50% to electricity. Yes, it is not a production unit. But given the efficiencies of the Capstone units (which are available right now), as well as all the advantages that this turbine has over the Capstone turbines (more efficient heat exchanger, axial flow design, ceramic turbine), these figures seem completely believable. Oh, and this is a 400HP turbine. Imagine having THAT under the hood of a Civic! Although it might be on the big side as far as power, it would probably still be more efficient than a conventional ICE - especially if run in hybrid configuration with battery power around town. Now THAT'S what I call 'flower power' right there!
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The big complaint from the consumers was poor fuel economy at idle and lower speeds. Unfortunately, this wasn't something further refinement could alter very much, since high rpm is inherent in gas turbine operation. I suspect this was the main reason that the U.S. Government ended its support for Chrysler's turbine research--the Goverment's goal was to lower fuel consumption in vehicles, not increase it, never mind the fuel flexibility.
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Besides the fact that their turbine was probably not NEARLY as efficient as the aforementioned microturbines, the efficiency of Chrysler's design certainly suffered due to the fact that they simply geared the turbine to the wheels of the car through a conventional transmission - the turbine HAD to run under conditions where efficiency would be low. Had they been able to use some sort of hybrid drive at the time (so that battery power could be used during low speed operation), the outcome might have been considerably different.