In 1966, vehicle classification and rules were based on the SCCA’s A and B Sedan amateur classes. A Sedan was called the Over 2.0-Liter category. The cars competing in the group were limited to a 5.0-liter engine and provided a platform to showcase the new ‘Pony Cars.’ The Under 2.0-Liter category included vehicles from BMW, Alfa Romero, British Leyland and Porsche.

The Trans Am series and its regulations have evolved over time. The championship has undergone changes to the race formats, vehicle eligibility and rules governing the cars.

In 1997, the Sports Car Club of America celebrated the thirty-second year of the Trans Am Championship. The season began with the series 341st race.

Trans Am rules require that vehicles be constructed with a purpose-built tube frame chassis. The top chassis builders include Riley & Scott, Roush, Weaver, Selix-Weaver, Hoerr, Rocketsports and Pratt & Miller Engineering. The bodies are made of composites, such as carbon fiber, Kevlar and fiberglass. The rules stipulate that the cars should maintain the recognizable external features of the manufacturer's model while providing flares necessary to keep the tires inside the bodywork. SCCA Pro Racing uses body templates to ensure the shape of cars is within designated tolerances. Cars are required to use the stock windshield or an approved alternative, which has to be mounted in the original location and at the original angle. The rules also dictate the use of the stock taillights, which are often the only production parts on the vehicles. The popular models are the Chevrolet Camaro and Ford Mustang; however, other vehicles eligible for the series include the Chevrolet Corvette, Pontiac Grand Prix and Oldsmobile Cutlass. Car styles cannot be more than five years old. All cars are required to use an American-based engine. The rules allow a 358 cubic inch 9:1 V8 engine with a car weight of 2700-lbs or a 355 cubic inch tipping the scales at 2775-lbs. Another option is a V6 with a 275 cubic inch engine weighing 2500-lbs. But the most popular choice is a 311 cubic inch motor. All options must be fitted with a 4150 Holley carburetor.

The thirteen race season began in February at St. Petersburg. Next, teams travel to the west coast to compete at Phoenix. Upon returning to the east, the championship stops at Lime Rock Park, Detroit and the Mid-Ohio Sports Car Course. On the calendar next is a string of events conducted on temporary circuits at Minnesota, Cleveland, Ohio and Trois-Rivieres, Quebec. In August, the championship visits Watkins Glen International and Road America. Then teams head north of the border for an event at Mosport Park. The penultimate weekend of the series is held in Pikes Peak, with the finale taking place on October 19th in Reno, Nevada.

In 1996, the Sports Car Club of America introduced the Goodyear Fast Five Qualifying procedure. The five fastest qualifiers are inverted for the start. This led to a number of different qualifying strategies – some teams decided to run slower for a better starting position while others tried to be the quickest and earn the bonus points.

Mosport was the eleventh round of the 1997 Trans Am series. It was also the series’ twentieth visit to track. Drivers would compete in a forty-lap event around the ten-turn 2.459-mile road course.

The track was wet for the start but dried quickly, forcing most competitors to stop for a change of tires.