SCCA TRANS AM RACES SERIES
Each manufacturer have to run its flagship models in production racing. The Firebird build by PONTIAC made no exception to the rule by participating in the Trans-Am races series. It featured the best Muscle Cars-stuffed horses and competing on the twisty circuit. As the Mustangs, the Barracuda, Camaro, Javelin, Cougar all on tracks like Laguna Seca.
These SCCA (Sports Car Club of America) Trans-Am race series for production sedans were reserved for cars with engines less than 305 cubic inches (or 4995cm3). These races, in which we could see the best thoroughbreds U.S. took place from 1966 to 1972.
The Pontiac didn't have the engine displacement in 1968 and then used the 302ci CHEVROLET. PMD had to create a 303ci small block, based on 400 RAM AIR IV. bore/stroke: 4.12"x2.87" (compared to the 4.12"x3.75" 400ci) and TRW forged pistons that provide 12.5 compression. The valves were 1.73" and 2.19" in diameter. The fuel supply was entrusted with two 600cfm Holley carburetors. All this gave a very sophisticated engine with maximum torque located beyond 8000tr/min and 430 horses at the flywheel! This 303ci was installed in a Firebird Trans Am 1969 model and was stirring up trouble on the track, but it did not happen because the engine did not comply with the rules and was therefore not allowed to run.
Some pictures are coming from historictransam.com
The 303 was extended to 1970 when new rules came into being and support adaptation engine 305ci series of more than playing on ratings bore and stroke. Thus Chrysler, far away from these races, took the opportunity to adapt its V8-340 and run the Barracuda and Challenger. It also allowed the use of crankshaft, camshaft, rocker arms, connecting rods and bearings not from the series. As against the carburetion was limited to the use of a simple carburetor (4BBL anyway!) with a carb valve maximum diameter of 1.687"(42.85mm).
Somes vintage film:
Unfortunately, because of the high costs to run in SCCA T/A, builders and private stables abandoned this formula, leaving more room for import vehicles such as Porsche and Jaguar who were present in these races since long time.
Since 1949, PONTIAC has 154 victory and only one title (in 1961 with Ned Jarrett in a Pontiac Catalina 389ci V8), but this is due to the fact that Pontiac is not officially involved in NASCAR since 2003. Do not forget that since 1980 the Pontiac engines are powered by Chevrolet.