He Makes a Change for Better : Auto racing: Fangio scores upset victory in San Diego GT race after engine is replaced.

Chip Robinson needed a miracle in the Camel Grand Prix of Greater San Diego to win the GT Championship Series title. He didn’t get it.

Jay Cochran needed to keep his Chevrolet Spice out of trouble long enough to let Al Unser Jr. get in the cockpit. It didn’t happen.

And Juan Manuel Fangio II needed to replace the engine on his Toyota Eagle after a disappointing Saturday qualifying session.

Fangio, the namesake nephew of the five-time world champion, took his new engine and drove it to victory on the 1.62-mile course on the Del Mar Fairgrounds.

“The car was very good,” the Argentine said after winning by 1 minute 1.29 seconds over Jaguar’s Davy Jones in the 87-lap race. Nissan’s John Paul Jr. took third.

The victory was worth $50,000 to Fangio, who averaged 78.836 m.p.h.

Jones took second despite losing a turbo two hours before the race in practice. The pace cars had already started the field on its way when Paul finally roared out of the pits. He eventually took the lead on lap 39 and held it until lap 61.

Unser, the fastest qualifier with a track-record 94.828 m.p.h. Saturday, never had a chance to get in the car. Cochran, the second-fastest driver to Unser in Friday’s practice sessions, started the race on the pole and was simply to put in some laps; he and Unser would change positions under the first yellow flag after 30 minutes, allowing Unser to drive the rest of the 1-hour 45-minute race without stopping for fuel.

Instead, Cochran ran in first place for 18 laps before Ruggero Melgrati, driving a slower Camel Lights car, ran him into the wall at Turn 5. In the pits, Unser shrugged.

“I’m just awfully sorry for the Spice team and for Jay,” Unser said. “From what Jay said . . . there was nothing he could do. He was running conservatively and consistently.”

Said Cochran: “I feel sorry for Chris Pook (Del Mar Race Management president) and Al,” he said. “The car was brilliant.”

Said Melgrati: “He probably tried to pass me on the left. It’s neither one of our faults.”

To win the GT championship, Robinson needed to win the race and have leader Geoff Brabham finish out of the top 10. Robinson reached second place but finished fifth.

Brabham won $150,000 for winning the title, his third in a row.

James Weaver was disqualified by IMSA and fined $5,000 for improper driver conduct. IMSA ruled he deliberately ran over sound-control equipment after being told to correct a noise problem on his Porsche.