On the outside, the Volt Vette...
On the outside, the Volt Vette is all C4, from the factory paint to the aluminum 16-inch wheels.
There's a lot of speculation these days about the future of the automotive hobby, especially when it comes to performance. Corvette enthusiasts have enjoyed more than a half century of tire-shredding internal-combustion power, but the push for hybrid and electric vehicles in recent years is enough to prompt the question: What's next?
Michael Shoop of St. Louis Park, Minnesota, might have the answer. Shoop is a Corvette guy from way back. He restored a '63 roadster to get over an ex-girlfriend in his mid-20s and later revived a '71 454ci Stingray-he's got an extra front bumper from that car hanging as modern art in his living room. Michael sold both Corvettes in the late-'70s so he'd have enough cash to live off while developing his nature photography business, but they wouldn't be his last.
Other than the missing gauges...
Other than the missing gauges and a few switches, the Volt Vette's interior is stock '87 Corvette.
Even back then, Shoop was fascinated with the idea of an all-electric car. He had always wanted to build one and when gas hit $4 a gallon in 2007, he decided it was time. He made a deal with his wife to spend less on the project than the cost of a new Toyota Prius, which was around $32,000 at the time, and he started hunting for a car. In the beginning he wasn't sure what type of vehicle to go with, but he knew he wanted something with style. Michael said, "My dad gave me this coffee table book on the first 50 years of Corvettes. And I was searching all over trying to figure out what car to convert because when you decide you're going to convert a car to electricity, choosing the right car is really important."
As Michael puts it, if you hate Edsels and you convert an Edsel to electric power, you're still going to hate the car. Simple enough. So what car would he be willing to spend undoubtedly countless hours toiling over in his pioneering conversion attempt? "From the book I discovered that the C4 Corvette didn't weigh any more than my Saturn, and with the clamshell hood and whatnot, I thought I could get in there fairly easy." Plus, the car looked cool, so the decision was made. His electric car would be a Corvette. Michael soon plunked down $7,400 for a clean, 109,000-mile '87 coupe with an automatic transmission and 3.07 gears. He recorded a solid 30 mpg driving the car as it was, but its gas gulping days would soon be over.
The car's computer system...
The car's computer system and forward batteries are prominent under the hood. Here, the lid of one of Michael's custom fiberglass battery boxes is removed to show the batteries. The TransWarp motor can be seen just aft of the battery box, tucked under the firewall. Michael was able to use the stock motor-mount holes to install the motor.
After much research and guidance from the Electric Auto Association and several electrical engineers, Shoop devised a plan that involved 13 lead-acid batteries fueling a 240-pound, 11.45-inch diameter electric motor. He shares that electric car folks talk in terms of motor diameter more than horsepower and an extra inch can make a huge difference. He originally planned on a nine-inch motor, but decided to go with the larger diameter so the car would have no trouble performing at freeway speeds and beyond. The motor Shoop settled on is called the TransWarP11 and is fitted with a double ended armature shaft so it can both drive the car as well as the alternator and accessories. It's also equipped with a TH400 tailshaft housing allowing it to bolt right up to the driveshaft without a transmission. Another convenience is the motor's ability to run at different power levels, which Michael can dial in using a palm pilot connected to an on-board computer. He said the motor will make roughly 100 hp at 92 volts, 200 hp at 156 volts, 400 hp at 300 volts, and 800 hp at 600 volts.
Right now, the Corvette's 13 old-school lead-acid batteries limit it to 156 volts. Newer, lighter, and more powerful battery technology hasn't come down in price enough yet to make it feasible for the backyard builder on a budget. When it does, Shoop might make a swap, but for now he's focused on testing the car the way he and his crew meticulously built it.