In 1969, the Sunoco-sponsored Roger Penske Camaro with the legendary Mark Donohue as the top driver repeated their previous domination of Trans Am racing by winning another eighteen out of twenty-five races.

It took first place at Michigan International, Bridgehampton, Bryar Motorsports Park, Mont-Tremblant, Watkins Glen, Laguna Seca, Sears Point and Riverside during the 1969 racing season.

Several modifications had to be made to the Camaro before it became the championship Trans-Am racer that made the Camaro nameplate into a road-racing legend. The most predominant of these was the acid-dipping process in which the Z28 undertook before being delivered to Roger Penske. Acid-dipping on race car bodies was a common practice for the time, and the purpose of dipping a car body in acid was to lower overall mass while maintaining the car’s strength and rigidity.

Other track-oriented modifications to the Z28 included air channels built-into the doors for increased airflow to the rear brakes, quick-release brake pads and a custom-lube system in which oil could be added to the engine once it reached racing temperatures. All of these modifications are primitive, or so they seem, but the Penske team was the only one at that time who was using them, which allowed Penske to be more competitive than any other racing team at Trans-Am, winning more professional races at an increasingly-faster rate.