Ad Radar
Car Craft
Click here to find out more!

1971 Supercharged Buick GS

A Force-Fed 455 To Challenge All Comers

Photography by Terry McGean

The facility at Barona Speedway is intimate enough that we could see the big brown Buick rolling to the line from our car while we paid the entrance fee. This made us nervous because we knew it was David Durell's first time back to the eighth-mile track since assembling the '71 GS with its new 455, but even more important, it was his first time out with the new Vortech supercharger. The likelihood of something shredding before it could be captured on film seemed high.

Blow-through systems for carburetors have taken great strides in recent years, allowing carbureted engines to enjoy the benefits of centrifugal supercharging previously reserved for late-model EFI cars. But seeing one strapped to a Buick engine that's been out of production since 1976 is still intriguing, especially since no one is currently offering a kit to do so. That didn't prevent David from pursuing the combination, working with Greg "Driver" Sadeau of GES Engineering to design and fabricate the blower moorings and work out the engine combination. And now it was time to try it out.

Moments later, the Buick emerged from the return road, seemingly under its own power and without accompanying death rattles or streams of vital fluid. The sinister grin on David's face as he hopped out confirmed the success of the first outing, though as we soon learned, he was already on pass number three. His personal goal for the day, aside from keeping everything together, was to break into the six-second range; in quarter-mile terms, that's a solid 10-second ride. It hadn't happened yet, and while David was taking it easy on the launch to safeguard the stock 8.5-inch 10-bolt, the Buick was still listing hard to starboard every time the lights came down.

During a cool-down break, we got the back story of the blown Buick. While the combination is new, David's relationship with the car is not. Purchased 12 years ago, when David was 22, it was first raced with a stock-ish 455. Soon, pocket-ported stock heads, a small cam, an aluminum intake, and headers had it in the 12s. "The '70 Stage I cars were good for 13.30s stock, and it's really not hard to make a standard 455 even better," he offered, in part to convey the ease with which the heavy Skylark dipped below the 13s. No doubt David's experience helped the e.t. "I probably had 800 passes on the car before I pulled it apart for this configuration; I used to race it somewhere almost every weekend for years." Eventually the Buick saw mid-to-low-11s with another 455 and a small nitrous system.

Back in the lanes, the plan is to lean on it just a bit harder during the launch for that extra nudge. When the lights come down, the left front clearly comes off the tarmac, and in a flash, the scoreboard tells the tale: 6.98 at 100.48 mph. Back in the pits, David and bud James Seabrook are pumped. "I'm still not launching off the converter, and it's pulling like a freight train!" Subsequent runs would shave the e.t. down to 6.94, which according to our conversion charts is a 10.60 or so in the quarter.

"I'm hoping that once I get a rear that can handle it and figure out the tune, we might get it into the 9s and still drive it home," offered David at the day's end. The following Monday he'd call to let us know that the lack of boost he'd been seeing on the gauge was accurate-the bypass valve was stuck open. In essence, the blower was possibly drawing more power than it was adding. All of this may just mean that a street-driven, nine-second, 4,000-pound Buick isn't simply possible, it's probable.

Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!
Car Craft