We’re chronicling 100 days of Indy 500 history on #SpeedRead leading up to the historic 100th Running. With 82 days to go, racing journalist Marshall Pruett continues his look back at milestone cars and technology.
More Pruett: Yunick’s winged Watson | Murphy’s Miller straight-8 | More 100 days
If there’s one car that has become the defining image of the Indianapolis 500, it might be the turbine, also known as the STP-Paxton Turbocar.
Team owner Andy Granatelli took pride in pushing boundaries at Indy, and with his wedge-shaped 1967 creation nicknamed the “Silent Screamer,” the combination of a gas-turbine aviation engine, all-wheel-drive, and a slick chassis with independent suspension gave Parnelli Jones a legitimate shot at victory.
Granatelli’s dayglow orange machine wasn’t the first turbine to appear at the Speedway—that distinction belonged to John Zink in 1961. Zing’s Boeing turbine-powered car was reliable, but didn’t have the raw speed required to compete and was withdrawn before the race. As he wrote in his book “They Call Me Mister 500,” the potential contained within Zink’s car was filed away for future use.
“The turbine concept was perfectly legal,” Granatelli wrote. “It had been legal, in fact, since 1955, when USAC had added that paragraph to its rule book, ostensibly to induce progress in racing. All right then, progress they wanted, progress they were about to get.”
The 1967 STP-Paxton Turbocar — not a champion but still one of the race’s most revered rides.
The sonorous Novi engine had been Granatelli’s main endeavor at Indy for years, but with the turbine concept fresh in his mind, a project was started in 1966 that would eventually involve a certain 1963 “500” winner who was more than reluctant to trade a conventional piston-engine car for the whoosh of the Turbocar.
“What happened is I’d run the Novi during a tire test once and went faster than anybody else,” Jones told IMS. “From that point on Andy [Granatelli] was hounding me to drive the Novi, and I wouldn’t do that because it didn’t have any reliability at all. He kept hounding me and taking me to dinner trying to get me to drive the Novi. We became really good friends, but I wasn’t interested. When they built the turbine car, it was pretty well along, not quite finished, and he called me up one day and said, come over to Santa Monica, I want to show you. That’s when I seen the car for the first time. I figured it probably wouldn’t work.”
Granatelli’s persuasive powers eventually resulted in a test drive for Jones.
“I was testing my own car in Phoenix about a month later, and I said, bring it over there and I will take a ride and see what happens,” he continued. “The more I ran it, the more I got interested in it. I don’t think I ran as fast as I did in my car, but it had potential. But it had a three-second throttle delay time, and that bothered me somewhat.”
Compared to an Indy car with an internal combustion engine, which had immediate power and torque to deliver once a driver pressed the throttle pedal, the mechanics of the turbine engine meant its power—and stupendous torque—were like a turbocharged engine with horrible lag. At low rpms, the turbine had little to offer, but once the mixture of compressed air and fuel ignited and the big turbine started to spin, a rush of propulsion was sent to all four axles.
The Turbocar’s layout was another unique aspect of the radical machine. The length of the Pratt & Whitney engine, and its need for a length air intake to feed the turbine, required installing the motor on the left and the driver on the right. With the bodywork removed, the sidecar-like cockpit is evident.
For Jones, who was accustomed to instantaneous response, an adjustment was required where he stepped on the throttle moments before it was needed to ensure the car’s acceleration happened when desired. As he explains, hiring a proven Indy 500 winner to pilot such a strange machine was not going to be easy—or inexpensive—for Granatelli.
“I thought I could make the race with it, but I didn’t know if I wanted to drive it or not,” he said. “I asked myself, ‘would you do it for $25,000?’ I said, ‘no.’ ‘Would you do it for $50,000?’ I said, ‘no.’ ‘Would you drive it for $100,000?’ ‘Yeah, I think I would give it a go,’ and that’s the number he agreed to finally.”
The Turbocar’s strengths were found in the corners and for a portion of each straightaway at Indy. Qualifying sixth, the “Silent Screamer” went from an oddity with a proven hero behind the wheel to a legitimate Race Day threat.
“I thought maybe I could make the race with it; I didn’t know it was going to be as good as it was during the race,” Jones admitted. “I liked the four-wheel-drive. People didn’t give the car any credit how well it handled. The car was really fast in the corners. The turbine had tremendous torque that and jumped it out on the long straightaways.
“About halfway down the straightaway it would accelerate, then it would stop. That’s why the guys were passing me during practice on light fuel loads; they could drive right by me. They figured I was backing off. That’s when the sandbagging claims came in but the turbine didn’t have the power coming in the whole way on the straightaways. They were faster in qualifying, but I could run just darn near as fast as I qualified in the race and they all just slowed down.”
Like the car itself, the turbine’s dominance in 1967 – and failure with the finish line in sight – is another unforgettable Indy 500 tale.
“Then it happened,” Granatelli wrote. “Jones had led 171 of the 200 laps. And with 197 laps in the bag, and only a pitiful three laps, or 7.5 miles, to go—with the race all but won—he coasted to a stop in our pits. It’s all history now, of course. A six-dollar ball bearing had failed in the critical gearcase. Our fantastic Turbocar and Jones were out of it.”
A.J. Foyt would sweep into the lead to earn his third victory at Indianapolis as the turbine idled on pit lane, it’s engine disconnected from its four Firestone tires. Due to attrition, Jones would be credited with a sixth-place finish. Of the many great swings taken by Indy 500 entrants, the Turbocar could be the greatest of all. It drew crowds, was loved and hated with immense passion, inspired fans and engineers alike to think in new and unrestricted ways, and crowned the 1960s as the most inventive decade the Speedway has ever seen.
It also forged a permanent link with the man who came within minutes of earning the biggest upset in Brickyard history.
“Actually, the car got most of the credit because it was so unique, and everybody still talks about it,” Jones said. “The people sometimes are surprised that I was the one who drove it!”
The No. 40 car was a showpiece with a flashy team to match, from the showman Granatelli (red jacket) to the STP-clad crew.