The year 1988 would mark the Buick Regal's change from its old rear-drive G-platform to a new front-drive W-platform, but also signaled the end of the Grand National - arguably, one of the sportiest Buicks built since the 1970s.; To celebrate - and go out with a bang - Buick decided to build the ultimate Grand National: the 1987 GNX.
GM engineers began work on the project in late 1986, partnering with colleagues at American Sunroof Company and McLaren Engines to develop the program.; Given the budget and time constraints, no party had time to re-work the innards of the Grand National's 3.8-liter turbocharged V-6 - but they could work on external components.
The motor was treated to a modified Garrett T-3 turbocharger with a ceramic impeller, revised intake and exhaust systems, a larger intercooler, and a tweaked engine computer.; These changes yielded 276 hp and 360 lb-ft of torque - a significant boost from a base Grand National, which in 1987, delivered only 245 hp.
They also yielded some impressive performance figures.; Two GNX prototypes hit a drag strip in 1986, laying down a 0-60 time of 5.38 seconds, and made a quarter-mile sprint in 13.47 seconds at 104 mph - outperforming a naturally-aspirated Porsche 911 and even Chevrolet's own Corvette.
Some mild chassis changes (like new rear torque bars and a Panhard rod linkage) helped channel that power to the ground, but the GNX remained a sleeper.; With a monochromatic black exterior, all production cars looked nearly identical to a normal Grand National, save for small emblems, fender portholes, cross-lace alloy wheels and analog gauges for the driver.
Such performance didn't come cheaply; the GNX option package ran for nearly $10,000, bringing the total price for a car to a whopping $29,900 (nearly $57,000 in today's economy).; That didn't deter buyers; Buick had to raise production figures from an initial cap of 200 cars to 500 to meet demand.; Ultimately, 547 examples were built, making the 1987 GNX one of the most collectible - if not powerful - Buicks to date.