Mark Donohue - Trans-Am

Trans-Am

Donohue began his Trans-Am series campaign in 1967, winning three of twelve races in a Roger Penske-owned Chevrolet Camaro. In 1967 and 1968, Trans-Am schedule included two of the most prized endurance races in the world, the 24 Hours of Daytona and the 12 Hours of Sebring. Donohue finished fourth at Daytona and won the Trans-Am class at the 12 Hours of Sebring.

1968 would be a banner year for Donohue in the Trans-Am series, as he successfully defended his 12 Hours of Sebring victory by partnering with Craig Fisher and driving his Penske Chevrolet Camaro to victory. Donohue went on to win 10 of 13 races, a Trans-Am series record which would stand until Tommy Kendall went 11 for 13 in the 1997 Trans-Am championship, winning the first 11 races that year in his All-Sport liveried Mustang.

Donohue was considered a leading Trans-Am driver of the late 1960s and early 1970s. His Camaros and Javelins won three Trans-Am championships (his last in 1971) while driving Camaros and AMC Javelins, all for Roger Penske Racing.

During their enormous success in Trans-Am, Roger and Mark would begin to experiment with their Camaros. They discovered that dipping a car in an acid bath would eat away small amounts of metal, which in turn made the car incrementally lighter, and allowed it to be driven faster around the track. The 1967 Z-28 won its last race by lapping the entire field of cars, raising eyebrows throughout the paddock.

During a post-race inspection, race stewards discovered that the car was 250 pounds lighter than the 2800-pound minimum weight requirement. Donohue was about to have his race victory taken away for cheating, but Roger Penske stepped in. Penske warned that any disqualification would have the potential of motivating Chevrolet to pull all support for the Trans-Am series. After considering the potential consequences, the race stewards allowed Donohue's victory to stand, but the rules for the 1968 season incorporated a change whereby all cars would be weighed during the technical inspection before the race.

Penske and Donohue did not stop acid-dipping after this, however. Continuing the practice of reducing weight allowed them to place weights of certain sizes strategically in specific locations within the car, thus helping to balance the car while being driven on the limit. Acid-dipping car bodies was prevalent with competing Trans-Am teams as well.

They continued to use the "lightweight" car in 1968, at the Sebring 12-hour race. They changed the grille and taillight to the 1968 model, and then painted both cars identically. They sent the legal weight car through the technical inspection with the number 15 and again with the number 16 on it. Then they put both cars in the race, number 15 and 16, one car being 250 pounds lighter. They won the race, finished 3rd overall, and went on to win 10 out of 13 races that year.

They also acid-dipped the body on the Camaro and had to caution people not to lean against it, for fear it would dent. The lightweight car was featured on an episode of Dream Car Garage on Speed TV in 2005.

In 1970 new Javelin team owner Roger Penske and driver Mark Donohue would breathe new life into the AMC team. Donohue drove the Javelin to three victories and finished second overall in the manufacturer’s championship and missed the driver's championship by only two points. In 1971 Donohue won the final six races in a row and seven out of nine to become the Trans-Am Champion. In the final race of the season, all three Javelin’s finished in 1st, 2nd and 3rd places making AMC the season winner among all manufactures.