Auto Racing: Reining in the Turbine

"Impossible!" growled Andy Granatelli, the Illinois millionaire who developed the controversial turbine-powered car that came within a hair of winning this year's Indianapolis 500. ;"A terrible mistake!" grumbled Parnelli Jones, the Californian who drove Granatelli's flame-colored STP Special at Indy and was only eight miles from victory when a $6 ball bearing failed. What angered Granatelli and Jones was a regulation adopted by the U.S. Auto Club last week that sets new limits on the power of turbine engines — thereby banning the STP Special from Indy.

The U.S.A.C. ruling reduces the size of a turbine racer's air intake from a maximum of 23 sq. in. to 15 sq. in. A 15-sq.in. intake would supply only enough air for a 480-h.p. turbine, while Granatelli's Pratt & Whitney aircraft turbine is rated at 550 h.p. The answer seems simple: replace the 550-h.p.

engine with a 480-h.p. engine. The catch is that no such engine exists.

Granatelli and Jones naturally branded the U.S.A.C. decision unfair. "Sure, we had an edge with our car this year," said Jones, "but it wasn't that big an edge." Not so, countered A. J. Foyt, who won this year's 500 in a conven tional 550-h.p. Ford after Jones broke down. A.J. claimed that the STP Special had more horses than Granatelli or Jones admitted — perhaps as many as 700. He may have a point. Turbines are notoriously affected by weather. On a hot day, a turbine engine may op erate at only 80% of its normal ef- ficiency. In cool weather, on the other hand, it may be 120% efficient, be cause cool air is richer in oxygen and nitrogen. And the temperature at Indy was an unseasonable 50°.