The Incredible Granatelli Turbine Corvette

On January 17, the hammer at the Barrett-Jackson auction in Scottsdale may fall on a one of a kind automobile whose heritage traces all the way back to the Indy 500 in 1967. That’s the race that saw Andy Granatelli’s all-wheel drive, turbine-powered race car lead the first 198 laps before a transmission bearing failed, ending its quest for racing immortality 2 laps short of the finish line.

But the love affair between the Granatelli family and turbine cars was not over. Years later, Andy’s son, Vince, shoehorned exactly the same type Pratt & Whitney ST6N-74 gas turbine engine that powered the Indy racer into a 1978 Corvette. Despite its size (it’s 3 times longer than the original V-8), the turbine weighs a mere 285 lbs. Using 80% fewer parts than an internal combustion engine, it cranks out 880 horsepower and an astounding 1,161 ft-lb of torque.

The front end of the car was gutted and a custom made subframe crafted to hold the engine and front suspension. A beefed up GM Turbo 400 automatic transmission was installed, driving 20″ Centerline wheels shod with Pirelli P-Zero tires through a 3.03:1 rear end. The turbine exhaust required a special rectangular box beneath the car, meaning that ride height had to be increased slightly. Finally, larger NASCAR-style brakes were fitted all around to bring all that speed and power to a halt.

What’s it like to drive this turbine Corvette? According to AutoBlog’s Basem Wasef, who got a turn behind the wheel recently, the experience is surreal. It’s a combination of being at the controls of a runaway train and filming a scene for the movie Top Gun. Once underway, the acceleration is not as instantaneous as it would be with a traditional Chevy big block under the hood, but when you press on the Go! pedal and the turbine spools up, the push is urgent and seems like it will never end. Visions of being at the Bonneville Salt Flats start to come to mind. An imaginary voice inside your head starts saying “Liftoff! We have liftoff!”

Motor Trend did a track test of the car in back in 1979. Powering up the turbine while holding the car stationary with those oversized brakes resulted in a 0-60 time of 3.2 seconds. That’s the same number as a modern day Tesla P85D. Observers at the 1979 test recall seeing twin black streaks of rubber leaving the starting line, steaks that got noticeably darker when the Turbo 400 shifted into second. 1,161 ft-lb of torque will do that for you. Amazingly, turbine-powered cars have yet to fade from public consciousness, even if they’re no closer to being mainstream than they were decades ago.

Wasef’s ride was limited to two laps and was inhibited somewhat by the guy in the passenger seat who was paid to see that nothing bad happened to the car just weeks before it went on the auction block.  Current owner Milton Verret says he has put about 1,000 miles on the car since he bought it in 1982. Will the car have a new owner soon? If so, it will be someone who just has to have the only car on the planet with an honest to gosh, bright red “Igniters” button on the console.

 

Steve Hanley

Closely following the transition from internal combustion to electricity. Whether it's cars, trucks, ships, or airplanes, sustainability is the key. Please follow me on Google + and Twitter.