Roger Penske had lured the multi-talented Mark Donohue out of retirement and back behind the wheel in 1975. One of the challenges placed before the gifted American driver was an attempt on the World Closed Course Speed Record set in 1974 by A.J. Foyt in his USAC Coyote on the 2.66-mile banked tri-oval at Talladega, Alabama.
Testing began in January '75 at Daytona, a similar tri-oval super speedway. Big engine problems were revealed immediately. The flat-12 engine, a 5.4-liter turbo-charged unit, had been designed for road racing, not for the sustained high revs of oval racing. As a result, overheating destroyed two or three engines before factory Porsche engineers were called in. After a great deal of development and testing, a pair of massive intercoolers were fitted. It was still touch-and-go, but it would have to do!
On August 9, during a break in the regular Talladega 500 activities, Donohue was released for the official attempt. Time was running short and so there was no time for a proper cool-down lap when Mark brought the 917/30 in for some last-second adjustments. A brief fire was extinguished, adjustment made, and back out on track on his second lap, the record was smashed! The official 221.160mph record stood in the United States for 11 years before Rick Mears finally took it away driving an Indy car.
