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Going Fast, Cadillac Style—Shawn Gilbert’s Twin Turbo 8-second Coupe DeVille


By Justin Norris

Photos by Kevin DiOssi and Mike Galimi

Shawn Gilbert’s Naples Yellow 1977 Cadillac Coupe DeVille is a fine specimen of Detroit opulence right down to the hood ornament, badges, power windows, and retractable antenna. Other than the chute and drag radials, it would be easy for someone to mistake this 4,000-pound, 8-second, cruise missile for a cruising land yacht.

Yet, the Elyria, Ohio native recently shocked the drag racing world when he entered his 1977 Cadillac Coupe DeVille in Radial vs The World at the 2017 Shakedown at the Summit, and proceeded to go rounds. It’s not every day you see your grand-pappy’s Caddy racing in a class reserved for the small tire elite, yet Gilbert is not your typical drag racer and he’s 100% a “Cadillac man.” Granted, this Malaise masterpiece was not throwing up RVW numbers, yet it proved that slow and steady sometimes wins the drag race. “In Radial vs The World we expected to go home in the first round against Frank Soldrige. I let go of the transbrake and he’s nowhere to be found,” Gilbert recounts. “It was pure luck that he blew the tires off, and we had a second-round bye. We went three rounds!” It wasn’t the first time we saw the Cadillac on track, but it was certainly more out of place in Radial vs. The World than anywhere else we’ve seen it compete.

In true car guy fashion, Gilbert’s story of past Cadillacs sounds like a recounting of past girlfriends, which helps set the stage for why he would bring an extremely heavy, chrome-gilded, knife to a gun fight. It all started nearly 20 years ago when he laid eyes on an El Dorado at the local dealership where he was working. After getting the Cadillac bug, Gilbert put the horsepower before the cart and purchased a 500ci big block Caddy and then found a silver 1979 Sedan DeVille to put it in. Then a slightly smaller yellow 1979 Coupe DeVille tickled his fancy and big Caddy engine was transplanted into that. One thing led to another, a phrase all too common among performance enthusiasts, and Gilbert had a 9-second nitrous huffing boat.

That car caught the eye of a collector in Denmark, who would become a trusted friend, and was sold in 2007. Next on the list was a white 1977 Coupe DeVille that was powered by a junkyard 6.0 LS engine and ran 11.40s on nuts. In the meantime, he was building a better 6.0 for the white car, yet it was sold before the transplant could take place. In 2011, Gilbert was reunited with the original yellow Coupe DeVille when he visited his Caddy buddy, Paul, in Denmark. This reignited the fire and led to the purchase of his second yellow 1977 Coupe DeVille. It started out with a big block Cadillac powerplant but soon made way for the compact LS engine. Gilbert finished the carbureted, nitrous-assisted, 6.0 he’d been building for the long gone white Coupe DeVille and put it in his most recent ride, which was the foundation for the boosted boat he has today.

The twin-turbo 6.0-liter LS under the hood is what separates this Caddy from its slower brethren. The true “LS truck motor” out of a 2007 delivery van is a testament to the strong power-to-dollar ratio of the LS platform; it’s sporting the stock GM crank with forged K1 rods and shelf pistons courtesy of Vic Ellinger at Wiseco. Topping things off are a pair of GM square port 821 heads, which accept boost from a pair of Borg Warner S366 turbochargers that were installed by Rick Trunkett at Big 3 Racing, who also dyno-tuned the Holley EFI system for pump-delivered E85 fuel. This boosted Caddy made 1,072 HP to the wheels through a Turbo 400 with a 9-inch converter from Perfect Converter Company in Walton Hills, OH.

His personal best to date is 8.52-seconds at 157 MPH on 24.5 PSI of boost. Gilbert, however, is on a mission to bust into the 7s this year and he’s making the right upgrades to get there, starting with a pair of Borg Warner S371 turbochargers from Forced Inductions, which are said to be good up to 1,900hp. Chilling the boosted air will be the job of a pair of Precision Turbo PT1001 liquid-to-air intercoolers. The plan is to hit the local heads-up venues this year—Dragway 42, Shakedown at the Summit, Milan Heads Up, and Pacemakers—and hopefully Gilbert will be collecting 7-second times at each stop along the way.

Mike Galimi
Mike Galimi
Mike Galimi is the Director of Content & Marketing at ProMedia Publishing and Events with nearly 20 years of experience in motorsport writing and photography.