GM A platform (RWD)
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- See also: GM A platform (FWD)
The General Motors A platform (commonly called A-body) was a mid-size car automobile platform. The A-bodies evolved from rear wheel drive compact cars to front wheel drive mid-size cars over the course of 35 years. The switch in drive layout in 1982 spawned the G-body. In the end, every A-body car line was cancelled, but new nameplates on the GM Epsilon platform have taken their place.
"Platform" does not mean sharing the same frame, but does mean sharing common parts. The Corvair was an A-body, but used unibody construction. However, it shared many component parts such as brakes, wipers, etc with other Chevrolet mid-size cars.
[edit] 1961
The first A platform was a "compact" (for the time) platform for the FR layout 1961 Buick Special, Oldsmobile Cutlass, and Pontiac Tempest and RR layout Chevrolet Corvair. It grew through the 1960s and 1970s as a rear-wheel drive platform, finally to be discontinued for 1982. High sales, however, kept the platform alive as the renamed G-body. This A-body was used in a wide variety of GM's most famous cars of the muscle car era, including the GTO, Chevelle, and Buick GS.
This single family of cars contained more innovative features than all other American products of the decade. Each model contained at least one notable advance:
- The Corvair's rear-mounted air-cooled flat-6 engine was the first American use of this engine design and location.
- The aluminum Buick/Oldsmobile 215 cid V8 was the smallest-ever American V8 and father of the Rover V8 engine. Both of these engines were turbocharged in 1962, making the Turbo Jetfire the first factory turbo engine.
- Buick also introduced the Fireball, the first American passenger car V6 engine, in 1962.
- The Pontiac Tempest had an innovative rear-mounted transaxle and flexible driveshaft, the first with this drivetrain design.
- Pontiac also had a notable half-V8 195 cid I4, the largest straight-4 engine produced after World War II. The 1963 Tempest Le Mans was also the prototype for the 1964 Pontiac GTO.
Ironically, every one of these new features was declared a failure and abandoned within a few years.
The Chevrolet Chevelle was the first A-body designed with a perimeter frame and 4-link coil-spring suspension - the 1964 model year was the first time the GM A platform had a full perimeter frame (similar to the design used in the 1963-67 Corvette); this would be known as the 'senior compact' between the full-size GMs (Impala, LeSabre, 88).
The original A-bodies were widely celebrated: The Corvair was Motor Trend magazine's Car of the Year for 1960, the Tempest won in 1961, and the V6 Special won in 1962.
[edit] 1973-1977
By this time, the American performance car was considered extinct, but these "forgotten years" had some performance left.
- 1973 Pontiac LeMans Sport Coupe GTO/Grand Am - Available with a 400 cid 230 hp V8 which was available with a 3 or 4-speed manual transmission or an automatic. There was also a 250 hp 455 with an automatic transmission only, which was announced but was never released to the public. Cars magazine tested an SD-455-equipped 1973 Pontiac GTO and chose it as Car Of The Year, yet it never made it to production.
- 1973-1975 Oldsmobile Cutlass Hurst/Olds W-30 - These were built using 455 cid V8 engines in the W-30 trim.
- 1976 Buick Century Turbo - These were originally built as Indy Pace Car replicas with a turbocharged and carbureted 3.8 L V6, and were faster than the 455 V8 version of that year. There were only a little over 1,200 built.
- 1977 Pontiac Can-Am - This car was basically a LeMans Sport Coupe with a Grand Prix interior and a Trans Am "Shaker" hood, a one-off wing and a 400 cid V8 rated at 200 hp with federal emissions, or an Oldsmobile 403 with California emissions. Only 1,100 or so of these were made and are getting quite collectible.
