Man turns Opel GT into a 75mpg serial hybrid.....in 1979!
Before 1979 became a hit song by the Smashing Pumpkins, it was the "International Year of the Child" as well as the year of the Three Mile Island incident. Sid Vicious died (though "punk" didn't) in '79 and president Jimmy Carter was attacked by a swamp rabbit. It was also the year that Mother Earth News, magazine of choice for sustainable-living enthusiasts, published the story of a man who built his own 75 mile per gallon serial hybrid with regenerative braking. Thanks to the miracle of the Internet and online back issues we can now, 29 years later, read all about this cool Opel GT (pictured above).
So you may be asking yourself, "If we could do this back in the '70s, where the heck is this car today? Did the oil companies suppress this technology too?" Well, after reading the article we think this car may be parked in a garage furnished with a long shelf lined with 100 mpg carburetors of the same vintage. In other words, we're a tad skeptical of the real-world practicality of the vehicle. According to the article, the car used a 5 hp lawnmower engine to charge up 4 lead acid 12 volt batteries that sent power to a 400 amp DC motor. Now, the car might actually have moved along near the 50 mph charge-sustaining top speed claimed but we suspect the batteries would have had an extremely short life-span. Of course, you may deduce differently, so read the three-page article and tell us what you think. Alternately, you could go all out and build your own, since plans for the car are still available through Mother Earth News.
[Source: Mother Earth News]
Reader Comments (Page 1 of 1)
T2 6:41PM (6/08/2008)
A gauge on the success of this vehicle would be to know the mileage covered since 1979, or the number of sets of batteries that the owner went through.
Some of these 'converts' are discarded before the first battery set is exhausted to ensure the builder can get some sort of return from the next sucker. Others destroy the battery pack by too many stoplight gran prix's then balk at laying out another $1500. Sorry to sound negative but even Pb-Acid needs some TLC if they are too survive and 100A from the generator is not enough unless the battery string is able to kick in 300A. A single string of 12v car batteries only good for 100A.
There are successful ones out there but they are not cheap to run when you factor in replacement battery costs every two years, plus vigilant battery monitoring/watering on a weekly basis.
Walley Rippel until recently with Tesla designed a controller for these vehicles back then although the Curtis is today's controller of choice.
Let's talk about the design. The Briggs and Stratton develops 28.5v at 1800rpm Ok. The four 12v batteries are in series. So their combined terminal voltage is 56v when fully charged. So how does that work ?
Most older aircraft starter/generators are 28v @ 400A although 300A and 200A are available and I've never seen a 56volt version.
My explanation is that he used golf cart style 6 volt batteries like any EV'er of the time would have told him. If so a series/parallel string of four batteries would safely provide 400A and would be compatible with a 28v charging system. Maybe future editions of Mother Earth News printed a correction, who knows ?
If anyone wants to go retro, it just so happens I have one of these motors lying around, I'll even throw in a 90 microhenry inductor rated for 400A in case you want to try your own home brew PWM controller $100 plus shipping will secure. ABG will no doubt want a report on how you managed !
T2
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Chris M 1:44AM (6/09/2008)
It strikes me as being extremely underpowered, with at best 25 hp (possibly 12.5 hp or even 6 hp?) driving the wheels. The 5 hp generator might be enough to sustain charge in slow speed stop & go driving, but would not be able to maintain charge during hiway driving. At best, it would extend the range of a undersized limited range battery pack.
Yep, there may be a good reason why it didn't catch on.
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Dave K. 7:52AM (6/09/2008)
Underpowered by current standards but remember there were still lots of 36hp VWs on the road in '79, also this was the last "energy crisis".
During this era new 4cyl engines rarely produced more than 75hp and V8s less than 200.
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Rich 8:15AM (6/09/2008)
I remember that article and was impressed but soon figured out that the numbers did not add up. Not enough batteries and a very short range.
I did find a nice used Opel GT for sale nearby.
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Alex Lopez 1:23AM (6/10/2008)
Amazing news. Past achievements shouldn't be forgotten, so let me introduce you what DIY guru Robert Q. Riley has done with his experience.
Since the late seventies, Robert Q. Riley have been selling plans to make high-mileage vehicles to any garage builder. His 'Centurion' used a small Kubota diesel engine to achieve 85 MPG @ 55mph or 128 MPG @ 35mph:
http://www.rqriley.com/cent.html
Last week, Mr. Riley started shipping his newest set of plans: the XR-3, a plug-in hybrid that takes the Centurion lessons into the 21st century.
The XR-3 achieves more than 200 MPG in Hybrid mode without using complex computerized controls. Its maximun speed is around 85 mph, can accelerate with ferocious power and still have a 150 MPG economy when stepping hard on the throttle. Read more and see the finished prototype here:
http://www.rqriley.com/xr3.htm
I don't work for Mr. Riley in any way, but I have been in a yahoo forum named 'xr3car' with lots of interested people, and Mr. Riley has been smart enough to keep close contact with us and redesigning the plans according to our suggestions.
So, if you are a tinkerer with some garage space, the XR-3 might be a valid option to other hybrids. And you will build it to your exacts specifications. What could be cooler than that?
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