STP-Paxton Turbocar
Encyclopedia
The STP-Paxton Turbocar was a racing car, designed by Ken Wallis as the STP
entry in the Indianapolis 500
.
, had developed a workable plan for harnessing a gas turbine to a race car. He first presented the idea to Dan Gurney
, who passed on the idea. Wallis then offered the plan to Carroll Shelby
and Shelby said (according to later court testimony), "Hogwash." Finally, Andy Granatelli
of STP expressed interest in the concept. Wallis and his crew moved in with Andy's brother Joe at STP's Paxton division in Santa Monica, and they began work on the turbocar in January 1966. It was Granatelli who introduced a side-by-side concept—that is, putting the engine at the driver's left. Granatelli also added four-wheel drive to the design.
The aluminum frame of the car was badly warped during heat treating in early 1966, eliminating any possibility of the car racing in the 1966 Indianapolis 500. Work started over again and the car was ready for the 1967 Indianapolis 500. Parnelli Jones
drove the car during tire testing in Phoenix early that year and was impressed with the car. He agreed to drive the car in the Indianapolis 500 after being offered $100,000 and half of any prize money he won.
Jones qualified the car at Indianapolis in sixth place at 166.075 mph. At the start of the race, he quickly took the lead and rarely relinquished it. However, with just eight miles left to go, he coasted into the pits with a transmission bearing failure. The car was refurbished and entered by STP in the 1968 Indianapolis 500. Driven by Joe Leonard, the car crashed into the wall during qualifying and never raced again.
The car was originally donated to the Smithsonian Institution
's National Museum of American History
by the STP Corporation. It is currently on loan to the Indianapolis Motor Speedway Hall of Fame Museum
.
turbine engine, was mounted on the left side of the backbone. The engine drove a Ferguson 4-wheel drive system, which transmitted the power to the wheels. A torque converter eliminated the need for a clutch pedal and gearshift. The engine idled at 54% of full throttle, which meant that the driver didn't even have to press the accelerator pedal to pull away; all he had to do was ease his foot off the brake pedal. A movable panel was mounted behind the cockpit, which acted as an airbrake. The suspension's coil springs were located inside the backbone and the suspension A-frames had airfoil cross-sections. The car weighed 1,750 pounds, a few hundred pounds more than the Indy minimum weight of 1,350 pounds.
USAC had limited the engine intake area to 23.999 square inches to limit the turbine's power output, but the engine still produced 550 hp. However, drivers reported that it had a three-second throttle lag. In less than a month after the 1967 Indianapolis 500, USAC cut the allowable turbine air intake area from 23.999 to 15.999 inches and imposed the ruling immediately, although it had been customary to give two years' notice of engine changes. With the reduced inlet area, the maximum lap speed that could be achieved was 161 mph.
STP (motor oil company)
STP is an American brand and trade name for the automotive additives, lubricants and performance division of Armored AutoGroup.Founded in 1953 in Saint Joseph, Missouri, the company’s name, STP, was derived from “Scientifically Treated Petroleum”...
entry in the Indianapolis 500
Indianapolis 500
The Indianapolis 500-Mile Race, also known as the Indianapolis 500, the 500 Miles at Indianapolis, the Indy 500 or The 500, is an American automobile race, held annually, typically on the last weekend in May at the Indianapolis Motor Speedway in Speedway, Indiana...
.
History
Wallis, a distant relative of famed British engineer Barnes WallisBarnes Wallis
Sir Barnes Neville Wallis, CBE FRS, RDI, FRAeS , was an English scientist, engineer and inventor. He is best known for inventing the bouncing bomb used by the RAF in Operation Chastise to attack the dams of the Ruhr Valley during World War II...
, had developed a workable plan for harnessing a gas turbine to a race car. He first presented the idea to Dan Gurney
Dan Gurney
Daniel Sexton Gurney is an American racing driver, race car constructor, and team owner.The son of a Metropolitan Opera star, he was born in Port Jefferson, New York, but moved to California as a teenager...
, who passed on the idea. Wallis then offered the plan to Carroll Shelby
Carroll Shelby
Carroll Hall Shelby is an American retired automotive designer and racing driver. He is most well known for making Mustangs for Ford Motor Company known as Mustang Cobras which he has done since 1965...
and Shelby said (according to later court testimony), "Hogwash." Finally, Andy Granatelli
Andy Granatelli
Anthony "Andy" Granatelli was the CEO of STP.Along with brothers Vince and Joe, Andy first worked as an auto mechanic and 'speed-shop' entrepreneur, modifying engines such as the 'flathead' Ford into racing-quality equipment...
of STP expressed interest in the concept. Wallis and his crew moved in with Andy's brother Joe at STP's Paxton division in Santa Monica, and they began work on the turbocar in January 1966. It was Granatelli who introduced a side-by-side concept—that is, putting the engine at the driver's left. Granatelli also added four-wheel drive to the design.
The aluminum frame of the car was badly warped during heat treating in early 1966, eliminating any possibility of the car racing in the 1966 Indianapolis 500. Work started over again and the car was ready for the 1967 Indianapolis 500. Parnelli Jones
Parnelli Jones
Rufus Parnell "Parnelli" Jones , is a retired American racing driver and racecar owner. He is most remembered for his 1963 Indianapolis 500 win, and almost winning the 1967 Indy 500 in a turbine car...
drove the car during tire testing in Phoenix early that year and was impressed with the car. He agreed to drive the car in the Indianapolis 500 after being offered $100,000 and half of any prize money he won.
Jones qualified the car at Indianapolis in sixth place at 166.075 mph. At the start of the race, he quickly took the lead and rarely relinquished it. However, with just eight miles left to go, he coasted into the pits with a transmission bearing failure. The car was refurbished and entered by STP in the 1968 Indianapolis 500. Driven by Joe Leonard, the car crashed into the wall during qualifying and never raced again.
The car was originally donated to the Smithsonian Institution
Smithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
's National Museum of American History
National Museum of American History
The National Museum of American History: Kenneth E. Behring Center collects, preserves and displays the heritage of the United States in the areas of social, political, cultural, scientific and military history. Among the items on display are the original Star-Spangled Banner and Archie Bunker's...
by the STP Corporation. It is currently on loan to the Indianapolis Motor Speedway Hall of Fame Museum
Indianapolis Motor Speedway Hall of Fame Museum
The Indianapolis Motor Speedway Hall of Fame Museum is an automotive museum on the grounds of the Indianapolis Motor Speedway in Speedway, Indiana, which houses the Auto Racing Hall of Fame. It is intrinsically linked to the Indianapolis 500, but it also includes exhibits reflecting other forms of...
.
Design
The STP-Paxton Turbocar was built around an aluminum box-shaped backbone. The driver was seated on the right side of the backbone, while the engine, a Pratt & Whitney Canada ST6B-62Pratt & Whitney Canada PT6
The Pratt & Whitney Canada PT6 is one of the most popular turboprop aircraft engines in history, and is produced by Pratt & Whitney Canada. The PT6 family is particularly well known for its extremely high reliability, with MTBO's on the order of 9000 hours in some models. In US military use, they...
turbine engine, was mounted on the left side of the backbone. The engine drove a Ferguson 4-wheel drive system, which transmitted the power to the wheels. A torque converter eliminated the need for a clutch pedal and gearshift. The engine idled at 54% of full throttle, which meant that the driver didn't even have to press the accelerator pedal to pull away; all he had to do was ease his foot off the brake pedal. A movable panel was mounted behind the cockpit, which acted as an airbrake. The suspension's coil springs were located inside the backbone and the suspension A-frames had airfoil cross-sections. The car weighed 1,750 pounds, a few hundred pounds more than the Indy minimum weight of 1,350 pounds.
USAC had limited the engine intake area to 23.999 square inches to limit the turbine's power output, but the engine still produced 550 hp. However, drivers reported that it had a three-second throttle lag. In less than a month after the 1967 Indianapolis 500, USAC cut the allowable turbine air intake area from 23.999 to 15.999 inches and imposed the ruling immediately, although it had been customary to give two years' notice of engine changes. With the reduced inlet area, the maximum lap speed that could be achieved was 161 mph.