The Buick GNX (Grand National Experimental) would debut in 1987 and only be sold for a single model year. The car was developed in partnership with McLaren Performance Technologies/ASC, and just 547 would be made.
Incredibly, the GNX would produce 300 bhp and 420 lb ft, remarkable figures for the 1980s and enough to make the car faster than both the Ferrari F40 and the Porsche 930 in the 1⁄4 mile sprint. This power was possible due to the highly-modified, turbocharged 3.8 liter V6 which made the Buick GNX one of the fastest American production cars of the time.
Fast Facts – The Buick GNX: Grand National Experimental
- The Buick GNX (Grand National Experimental) was a high-performance version of the Buick Grand National, introduced in 1987 for a single model year. Only 547 units were produced, developed in partnership with McLaren Performance Technologies/ASC. It featured a heavily modified, turbocharged 3.8 liter V6 engine producing 300 bhp and 420 lb ft of torque, making it one of the fastest American production cars of its time.
- The Buick Grand National series first arrived in 1982 as a limited-edition model based on the Buick Regal. It was initially planned for only 100 units but continued production due to its popularity. Over the years, it received incremental power upgrades to its turbocharged V6 engine, culminating in the ultimate GNX variant for the 1987 model year.
- The GNX received extensive modifications from McLaren Performance Technologies/ASC, including a specialized turbocharger, intercooler, ECU tuning, exhaust system, transmission upgrades, suspension upgrades, and aerodynamic body modifications. These changes allowed it to outperform contemporary supercars like the Ferrari F40, Porsche 930, and Lamborghini Countach in the quarter-mile sprint.
- The featured Buick GNX up for sale on Bring a Trailer is a low-mileage example, having covered only 26 miles from new. It has been carefully preserved in its original black paintwork and has a well-maintained interior, presenting an opportunity to own one of the rarest and most collectible American V6 sports cars in near-new condition.
Building The Grand National
The Buick Grand National first arrived in early 1982. It was named after the NASCAR Winston Cup Grand National Series as Buick had won the Manufacturers Cup in both 1981 and 1982, and they wanted to ensure that no one forgot.
The Buick Grand National debuted in 1982 to celebrate Buick’s back to back Manufacturers Cup win in 1981 and 1982 in the NASCAR Winston Cup Grand National Series. Image courtesy of Buick.
The Grand National was based on the Buick Regal, and initially, just 100 were slated to be produced as a limited-production special edition. The cars were shipped from Buick to Cars and Concepts of Brighton, Michigan who then fitted them with the Grand National package.
The package included a slew of modifications and new parts, a front air dam and rear spoiler were installed, the wheel opening moldings and rocker panel moldings were blacked out, and light silver-gray firemist paint was added down the sides.
Inside the cars were fitted with custom Lear-Siegler seats with silver cloth with black vinyl inserts, and a clock delete plate was added to the dashboard, carrying the “6” logo and “Grand National Buick Motor Division.” The first year of the Grand National was powered by the naturally aspirated 4.1 liter V6 producing a modest 125 bhp at 4,000 rpm and 205 lb ft of torque at 2,000 rpm.
There were a handful of these first year Grand Nationals, approximately 35, which were based on the more powerful Buick Regal Sport Coupe which had a turbocharged version of the V6, as a result they were capable of a more respectable 175 bhp at 4,000 rpm and 275 lb ft of torque at 2,600 rpm.
The Grand National would remain in production due to its incredible popularity, the original plan of only making 100 had been abandoned in the first year. The model would get more powerful year-on-year, producing 180 bhp in 1983, 200 bhp in 1984, 1985 would be the only year that remained unchanged, and 1986 would see it turning out 235 bhp. These were solid figures for the era, when emissions restrictions had caused even some cars with 5.0+ liter V8s to be producing under 200 bhp.
The Buick GNX: The Ultimate Grand National
1987 would be the final year for the Grand National as the “G-Body” Regal was due to be replaced for 1988. As a result, two versions of the Grand National were offered for this year – the standard Buick Grand National with all the upgrades and its turbocharged V6, and the new Buick GNX.
The Buick GNX would be the fastest and most powerful of all the Grand National series cars, producing 300 bhp and 420 lb ft of torque. Image courtesy of Buick.
The Buick GNX would be by far the most highly-modified of all the Grand Nationals, the name standing for Grand National Experimental, and it would be the final feather in the cap of Buick from the company’s wildly successful Grand National program.
Each GNX started as a regular production line Buick that was shipped off to McLaren Performance Technologies/ASC who would apply a raft of updates. These updates included the fitment of a special Garrett AiResearch T-3 turbocharger with a ceramic-impeller, a large capacity air-to-air intercooler, and a GNX-specific EPROM (erasable programmable read-only memory) – essentially an early ECU.
The engine was also fitted with a low-restriction exhaust with twin mufflers, a reprogrammed turbo Hydramatic 200-4R automatic transmission, a custom torque converter, a transmission cooler, and a Panhard bar in the rear to help keep the axle well located during spirited cornering.
The model also received an additional frame crossmember, a limited-slip differential and a “torque arm” mounted to a GNX only differential cover that helped keep the rear wheels planted under heavy acceleration.
A series of body modifications were also applied, both for performance and to help differentiate the car from the standard GN. Vents were added to each front fender, 16 inch black mesh-style wheels were installed with VR-speed rated tires, and the hood and fender emblems were deleted.
Inside the car you would find a serial number on the dash plaque, Stewart-Warner analog gauges, and an analog turbo boost gauge. Due the blacked out, menacing looks of the GNX it was nicknamed “Darth Vader’s Car” by some, however no official licensing deal was in place, and the nickname eventually petered out.
Power is provided by a turbocharged 3.8 liter V6, it was so powerful that the GNX could beat the Ferrari F40, Porsche 930, and Lamborghini Countach in a 1/4 mile sprint.
Power output was significant, the modified V6 was good for 300 bhp at 4,400 rpm and 420 lb ft of torque at 3,000 rpm. This gave the GNX a a 0 – 60 mph time of 4.6 seconds and a a 1⁄4 mile time of 12.7 seconds at 113.1 mph. This was enough to beat the Ferrari F40, the Porsche 930, and the Lamborghini Countach – arguably the three most famous supercars of the time.
Only 547 examples of the Buick GNX were ever made and today they remain among the most collectible American V6 sports cars ever made.
The 26 Mile Buick GNX Shown Here
The Buick GNX you see here is by far the lowest mileage example we’ve ever seen come up for sale, with just 26 miles on the clock. It’s fitted with air conditioning, cruise control, and a Delco cassette stereo. As you would expect it’s finished in its original black paintwork, and features a remarkably well-preserved interior.
It’s not hard to see why some nicknamed the GNX “Darth Vader’s Car.”
The car was kept in long-term storage for many years, and now presents almost like a brand new car as a result.
It’s now being offered for sale out of Thousand Oaks, California on Bring a Trailer with a clean California title. If you’d like to read more about it or register to bid you can visit the listing here.
Images courtesy of Bring a Trailer
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Silodrome was founded by Ben back in 2010, in the years since the site has grown to become a world leader in the alternative and vintage motoring sector, with well over a million monthly readers from around the world and many hundreds of thousands of followers on social media.
