The Trans-American Sedan Championship, or Trans Am, is a racing series sanctioned by the Sports Car Club of America since 1966. Despite being "Trans-American", the series has left the US many times.
The series was established in 1966 to capitalize on the growing interest in performance sedans, but used the smaller pony cars like the Ford Mustang instead of NASCAR's full size sedans. The series spun off from the SCCA sedan categories already in use. As per tradition, all cars were limited to a five liter maximum displacement. (Despite popular belief, there was no "under five liter" group, but rather the group was called "over two liter".)
The series was a success, and led to several manufacturers entering vehicles in the series. These included Ford, Mercury, Chevrolet, Pontiac, Dodge, Plymouth, and AMC. Everyone wanted glory in this new, popular series.
These powerful sedans were of course accompanied by the low displacement touring cars. This group is best known for the Alfa Romeo GTA, Datsun 510, BMW 2002, and Lotus Cortina. However, it was the Porsche 911 that dominated (the car likely being classified as a coupe at the time). Ultimately the class had cars from Italy, France, Germany, Britain, Sweden, and Japan.
1971 brought a new competitor in the form of IMSA GT, which ultimately absorbed Trans Am partially due to a decline of interest in performance sedans. Trans Am cars became IMSA TO and TU. During this time, and in later years Trans Am cars became increasingly less stock to the point where they barely if at all resembled their production counterparts (a la NASCAR).
The eighties brought a slight resurgence of Trans Am until 1988 was dominated by the Audi Quattro, an embarrassment to the series which led to an American muscle revival which would last for over a decade until Italian manufacturer Qvale (pronounced k'vawly) won the title. During this period, Trans Am acquired leftover NASCAR sedans.
Qvale and Jaguar would dominate the series after the turn of the millennium until the series' demise in 2006, after which Rocketsports Racing left for the American Le Mans Series.
After its hiatus, Trans Am returned and has since attempted a reformatting to return to its roots. Most classes are dominated by Chevrolet, with some classes featuring foreign cars. Dodge has since garnered its first win in over twenty years.
Lately the series has featured cars which are far from stock in one group, production cars in another, and foreign cars in another.
The series does not require the vehicles to be the latest model. Nineties Mustangs and Corvettes can still be seen in the series. According to the rules cars from as old as the 1990s are permitted.
The Trans Am Series, particularly the golden age, is often tributed in historic racing. These race groups are almost always the over two liter class, but with occasional under two liter cars mixed in. The Monterey Historic Automobile Races at Mazda Raceway Laguna Seca once featured an under two liter group.
Television series American Muscle Car dedicated an episode to the Trans Am Series. A few mistakes were made, however. The series is referred to as the "Trans-American Sedan Racing Series". The series was known as the "Trans-American Sedan Championship". Also mentioned is an "under five liter" class when in fact it was an "over two liter" class, with five liters being the maximum.