The G8, as well as the two-door GTO that preceded it by a few model years, had both been based on different versions of the Holden Commodore SS—a car that's held in high esteem in Australia, where it's assembled (and engineered).
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The Chevy SS that's now arriving at dealerships has some of those same roots, it can be argued; only this time it's based on the latest 'VF' iteration of the Commodore SS V (the top-performance model).So is the SS essentially the same car as the G8 GXP? Absolutely not, says Steve Manson, program engineering manager for the project.
Over several years, Manson's team took GM's Zeta architecture, which underpinned the G8, and updated it to a so-called Zeta 2 form—parts of which are used for the current Camaro.
Stripped down and done over
And to do this, Manson says that the engineering team took the original Zeta, stripped it down to the basics, and said “Alright, let's start again.”
While the SS holds essentially to the same dimensions as the G8, the team gave these Zeta 2 models new styling and new sheetmetal all around, as well as many new materials throughout.
“We looked at every sheetmetal panel, and changed quite a number of them from medium to high-grade steels in order to improve stiffness or chase mass,” said Manson, who added that the team restructured the front rails of the car in order to improve crash performance and gave the 'body in white' a pretty extreme makeover.
Manson said that at that point they'd shed about 30 pounds from the core structure.
“We then started building it back up again,” he said. “We put an aluminum hood and trunklid on the car to get the minimum possible mass there; we redid the door skins, we started building the car essentially from the ground up.”
Manson says that while the floorpan or other structural members might look close to the preceding car (only the hard points like roof pillars and glass location have stayed the same), they've in many cases changed to a higher-grade steel or exotic-grade material. Lots of pieces that previously were made of steel are now aluminum—although the team didn't use much magnesium in this application.
The engineering leader conceded that it's easy to be led astray by the evolutionary look. “So in the end the proportions are similar, but very little is actually the same.”
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Even electrical and interior are completely different
All of the electrical architecture of the old car went, too—in favor of GM's Global A architecture, which allows the SS to pick up some of the latest GM technologies like head-up displays and active-safety systems. That's good news, as when we last reviewed the 2009 Pontiac G8 lineup we noted its controls, displays, and connectivity as being below par for the time.
“We didn't carry over one bit of wiring or anything else,” said Manson.
Finally, the team redid the interior of the car, with completely new (and resculpted) seats, plus a completely new instrument panel, and a new aluminum support beam for the IP.