Electric 914s, what are the numbers? Options

[fiid]

I was talking to mueller a while ago about building turbine engines out of turbo chargers, and he said that that was basically what an aircraft APU (auxillary power unit) does.

Which gets me to wondering. I think it would be really cool to build an electric 914 that is powered by a turbine generator running on CNG.

Is this viable? With Otmar's setup this would be an interesting way to get 1000 ft lbs, but still maintain range. Plus you ought to be able to get access to Californias HOV lanes (either by running CNG or as a hybrid.

What kind of power output can you get from a small turbine generator?

[lapuwali]

Hm.. I started looking up some of those numbers, and it looks like a single stage gas turbine is only 40-50% efficient, not 80% as I stated.

I'd certainly not try to have the turbine directly drive the car at any time, as it would really complicate the driveline. As stated earlier, turbines like to run at one fixed speed, and have terrible throttle response characteristics. One big advantage of building a mostly electric hybrid is the driveline is fairly simple. No gearbox required. No clutch required. You'd still need a diff. I'd try to save the weight and ONLY run a diff directly off the electric motor. Or run two electric motors, one for each wheel, and forget the diff altogether (hey, controllable limited slip!). The gas engine is only there to recharge the batteries, so it can be located anywhere, in any orientation, and requires little to no gearing, other than what the generator would need (turbine, yes. Otto engine, no).

Perhaps step one would be build an all-electric car. Only add the gas engine later.