 Electric 914s, what are the numbers? |
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| fiid |
 Nov 5 2004, 10:36 AM
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Turbo Megasquirted Subaru Member  Group: Members Posts: 2,827 Joined: 7-April 03 From: San Francisco, CA Member No.: 530 Region Association: Northern California  |
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? |
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| lapuwali |
Nov 5 2004, 01:03 PM
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Not another one! Group: Benefactors Posts: 4,526 Joined: 1-March 04 From: San Mateo, CA Member No.: 1,743  |
As for power consumption, remember that at cruise, the car is only consuming about 10hp-15hp to maintain 60-65mph. So, you don't need a lot of turbine power to keep the batteries topped up while cruising. Theoretically, one could get by with a pretty small engine to power a generator just to extend range. A 250cc bike engine should be quite adequate. Perhaps you could run that on CNG just to make it all more complicated. (IMG:style_emoticons/default/biggrin.gif)
I'd also wonder about noise with a turbine. I have no idea how a turbine reacts to exhaust backpressure from a muffling system. I know Volvo make a turbine/electric concept car a few years ago, but I have no idea if they actually made it run. I just happened to be thinking about the efficiency issue with this kind of setup the other day. A turbine gets about 80% efficiency (fuel energy converted into mechanical energy). A four-stroke Otto engine has about 30% efficiency BEFORE a gearbox is involved. Turbine to generator to electric power to electric motor to mechanical drive I think cascades to about 20% efficiency, which is roughly the same as an Otto engine and gearbox. However, you can run on batteries alone in town and under acceleration, so no need for an engine of better than 20-30hp just to keep the batteries charged. Main downside is limited acceleration time before you have to wait for more charge. |
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Posts in this topic
fiid Electric 914s Nov 5 2004, 10:36 AM
airsix I see a few locomotives here and there that use tu... Nov 5 2004, 12:30 PM Mueller Ben,
I believe Fiid is thinking that the drive wh... Nov 5 2004, 12:41 PM Andy Wouldn't the noise be a serious issue for a st... Nov 5 2004, 12:43 PM bondo Hehe, I've thought about this :) The problem ... Nov 5 2004, 12:47 PM bondo Every turbine generator I've seen had at least... Nov 5 2004, 01:14 PM 3d914 fiid,
If you wait a short time, you'll have a... Nov 5 2004, 01:33 PM lapuwali Hm.. I started looking up some of those numbers, a... Nov 5 2004, 02:03 PM BiG bOgGs When talking about the efficency of the conversion... Nov 5 2004, 04:10 PM scott thacher one problem with your idea of a small high volt pa... Nov 5 2004, 08:51 PM BiG bOgGs Scott, the 24v bats I was speaking of are deep cyc... Nov 5 2004, 09:12 PM
3d914 If you're going to use a turbine to genereate ... Nov 7 2004, 08:18 PM |
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