- Joined
- Dec 15, 2018
- Messages
- 74
- Reaction score
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- Location
- Butler, PA
- Website
- www.pontiactransam.com
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Proportion is everything in automotive design, and GM’s second-generation F-bodies had it down. Free from the design constraints that came with styling the first Firebird and Camaro models on an existing architecture, the second-gen cars would have a body structure shared with no other vehicles. GM Design chief Bill Mitchell’s affinity for European touring cars drove the overall design theme, with the F-body proportions radically reimagined, pushing the passenger compartment farther back on the chassis. The result was a longer nose and fast-sloping rear profile, though surprisingly, the basic exterior dimensions weren’t all that different from the 1969 models.
The first- and second-generation cars shared a 108-inch wheelbase, and while the second-gen cars were noticeably lower, they were only fractionally wider. That longer, lower look was also reinforced with long doors and the elimination of the rear quarter-windows. Those doors made it difficult to squeeze out of the car in garages and parking decks, but such was the price of proportion perfection.
While the second-generation’s F-bodies’ future was ensured with the redesign, the Pontiac Trans Am’s was not. Plans for the second-gen were well underway when the comparatively paltry 697 Trans Am models were built for 1969. The car was intended as a homologation special for the popular SCCA racing series, just like the Boss 302 and corporate cousin Camaro Z/28. Unfortunately Pontiac’s Trans-Am racing engine program was never fully realized, so the production model had no ties whatsoever to its namesake racing series.
With such a low production run and no competition link, it’s no wonder Pontiac’s product planners didn’t see the marketing benefit in carrying over the model into the second generation. But they did, and the unique design cues were overseen by designer Bill Porter. He was there as specific features, such as the front fender vents, front spoiler, and fender spats, were drawn up, along with the functional shaker scoop pushing through the hood.
Porter was actually dead-set against the shaker scoop. An early version appeared on a first-gen performance concept featuring Pontiac’s OHC-6 engine, and the design was refined for the V-8 application, but Porter resisted. He thought it disturbed the flow of the long, sleek front end and suggested it wouldn’t really deliver a performance advantage. A pair of air scoops like nostrils at the forward edge of the hood, he argued, would be more aesthetically pleasing and effective for engine performance. Mitchell ultimately overruled Porter on the shaker scoop, but the consolation prize was that his twin-scoop idea was picked up for the budget-performance Formula model.
Interestingly, Porter also reportedly suggested using a large Firebird hood graphic to wrap around the shaker scoop he found so obtrusive in an effort to integrate it better in the car’s overall design—or at least take the emphasis off it. Mitchell nixed that idea too, but a smaller version of the car’s updated logo was used on the nose, heading up a stripe that ran up and over the body, culminating on the trunk. Porter moved on from the Pontiac studio a couple years later, but his idea for the large hood bird motif was picked up by his successor, John Schinella.
Despite his setbacks with the hood bird and shaker scoop, Porter was nonetheless rightfully proud of the second-generation’s design, calling it his favorite Pontiac in later interviews. Its proportions, he said, were spot-on.
One of the carryovers from the 1969 model year was the standard L74-code 400ci Ram Air III engine, which was rated at 345 hp (gross). It was offered with the wide-ratio Muncie M20 four-speed manual, the close-ratio M21 four-speed manual, or the Turbo 400 three-speed automatic. The 370hp Ram Air IV was optional; and with either engine, torque was funneled to the ubiquitous and sturdy, Safe-T-Track-equipped 12-bolt rear axle. It would be the only year the 12-bolt was available in a second-gen Trans Am.
It was also the only year the Ram Air III and IV engines would be offered in the second-gen cars, as the regulatory changes facing the entire auto industry brought an end to high-compression performance. In 1971, the Trans Am’s Ram Air engines were replaced with the 455 H.O., as Pontiac’s engineers tried to offset the power drop that came from reducing compression more than two points—from 10.5:1 down to 8.4:1—with torque-building displacement. It wasn’t a bad solution, but the halcyon days of the muscle car era were definitely in the rearview mirror.
In addition to the Ram Air engines and 12-bolt axle, a number of other components and elements were built into the 1970 Trans Am that made the car unique, starting with the oddball 15-inch wheels. The story goes that Pontiac planned on 15-inch versions of the Rally II design but could not get them made in time for the car’s start of production. So the center section of the 14-inch Rally II was used inside a 15-inch rim along with a 1-inch band of steel between them. The true 15-inch Rally II came in 1971.
