Hoonigan Racing Mechanic, Gregg Hamilton's, Twin Turbo LS Swap Bandit Trans Am

Author: Bradley Iger | Photographer: Larry Chen | 09/01/2020 < Back to Motor Life Home

 Although his hot rodding muses run the gamut today, Hoonigan Racing Mechanic, Gregg Hamilton’s first love was rallying. Originally from New Zealand, his interest in all things automotive was sparked early on by his father’s high performance projects, which led Gregg to start wrenching on Holden Toranas, Mitsubishi 3000 GTs, old Datsuns, and anything else he could get his hands on.

Hamilton’s technical prowess eventually landed him a job in Japan with the performance suspension gurus at Tein, assisting their Group N rally team, which in turn led to a stint in Germany working with Toyota’s rally team before he landed a gig with Prodrive in the UK. “And that turned into a job in Detroit with Subaru of America and Vermont SportsCar,” he recalls. “That’s where I met Ken [Block] and his crew.”

Gregg's experience as lead technical engineer for Hoonigan and other rally teams, gave him an insight on how to setup suspension(s). This Trans Am is not just a pretty face, but packed with QA1 goodies to make it curve corners as well.

He’s of course referring to rallying luminary Ken Block, whose supernatural car control has garnered international fame through his motorsport exploits, along with a steady succession of jaw-dropping Gymkhana videos over the years. Since 2011, Hamilton has served as the lead technical engineer for Hoonigan and Block’s various efforts, which include insane custom Gymkhana builds like the Hoonicorn and Hoonitruck.

Given that, it should come as no surprise that Hamilton has some pretty cool whips of his own. Of particular note is this ’79 Pontiac Trans Am, which balances old school cool with pro touring functionality, along with a healthy dose of the DIY sensibility that Hoonigan builds have become known for.

“You can blame Smokey and the Bandit for this one, really,” he says with a laugh. “Older Trans Ams are a lot harder to come by over in Europe, so when I moved to America, I knew I had to have one. So I found this car on eBay and flew out to Alabama to pick it up at the airport, basically sight-unseen.”

The project got underway in 2005, and although Hamilton says he didn’t really have a specific plan for the car going into the build, it slowly evolved into the killer pro touring-style build that you see here. “It came with the wrong engine,” he says of the original 403ci Oldsmobile V8. “And that promptly blew up.”

He decided to rebuild the Olds mill and breathe a bit of new life into the power plant while it was under the knife. “I put together a custom ECU kit so I could run fuel injection on it. And once I had that done, I figured since I had an ECU at that point, we might as well add some boost. So I added a couple of turbos.”

Hamilton also moved to Las Vegas that year and into a significantly larger shop in turn, which provided some more freedom to expand his work on the project. So after the Olds 403 gave up the ghost a second time, he decided to make the switch over to a 5.3-liter LS and throw in a few other tweaks for good measure, swapping the ’79 Trans Am nose for a ’78, ditching the stock front suspension for QA1 components, and lowering the rear to match. He also stepped up the stopping power by tossing the factory hardware in favor of a Corvette Z06 brake setup.

Under the hood we find an LS engine fed by a pair of Garrett turbochargers into the Holley EFI Mid-Rise Intake Manifold and 92mm Sniper EFI throttle body. Backed by a ZF six-speed transmission, it makes a modest 500hp, perfect for a weekend cruiser.

Under the hood, the LS has been warmed over with forged pistons and rods, an LS9 camshaft, a Holley Mid-Rise intake manifold, a Sniper EFI throttle body, and a pair of 68mm Garrett turbos with a custom fabricated intercooler. Running ten pounds of boost and breathing through a set of custom fabricated side pipes, it’s a combination that’s good for about 500 horsepower by Hamilton’s estimate. The original automatic transmission has been replaced by a ZF six-speed manual gearbox from a C4 Corvette, which sends the power to rear wheels via a limited slip rear end with 4.56:1 gears.

“We do a lot with the race cars, and I’ve always liked that widebody look,” he explains of the Pontiac’s aesthetic. “So I figured I could put some wide arches on it and extend the tail a bit – make it look a little different from stock but still like a Trans Am.” And to that end, he notes that Holley’s modular mid-rise intake manifold proved to be a great fit for the build. “It’s a two-piece design, so you can modify the top of it, and that was important to me,” he notes. “I wanted to maintain that Trans Am look, so I ended up mounting the hood scoop onto the hood itself, and I chopped about an inch off of the top half of the manifold to get everything to fit.”

Though Hamilton considers the Trans Am to be “done enough,” he admits that it’s really a never-ending project. “There’s always something I want to do to it – I’ll probably put an independent rear suspension on it fairly soon, and it could stand to get an AC upgrade.”

Understandably, his day job tends to keep him pretty busy. “Last year we did a big project with the pickup truck in China, and this year our calendar was pretty full with all the rally events until COVID hit,” he says. “Now we’re focusing on rebuilds in the shop, filming projects with the Mustang here and there, the general the day to day stuff of the team, and getting ready for the rest of the season’s racing.”

But in the meantime, Hamilton says the Trans Am build has reached a point where he can use and enjoy it for what it is. “It’s a bit of a cruiser, really. I take it out for drives and car shows whenever I have a chance.”

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