You read that title correctly — more than 1,100 horsepower at the tires from a twin-turbo 2020 GT500. You might be wondering what happened to the blower; according to HPJ Performance’s Doug Stroud, the car junkies in his area of Missouri are always trying to one-up each other with their builds, and this GT500 is no exception. This car is on the cutting edge of development, and we’re giving you a small peek inside at the details.
“We’ve had the idea to do one of these since the cars came out and didn’t have anyone to do it for,” he says. “We finally got one customer that was itching to make more power and liked the idea of turbos for keeping IATs down and easy boost control. The car went 9.59 on the factory blower,” said Stroud.
HPJ reached out to Hellion Power Systems for assistance, and the longtime turbo system manufacturer delivered. Although they didn’t have a system designed specifically for the ’20 Shelby cars, owner John Urist had confidence that the HPJ team could take the Hellion Mustang GT Sleeper twin-turbo system and adapt it for GT500 usage.
“We modified the system since this has never been done before, and documented our changes for Hellion to help them with development. The transmission lines have to be cut and redone along with some other changes, and most of your weekend mechanics are probably not going to do a good job of that,” said Stroud.
Urist concurs, and says this kit is the way forward for GT500 owners to make massive power. He was happy to work with HPJ on the development side; his belief entering the project that the kit would be mostly the same as the Mustang GT kit was borne out by HPJ’s efforts to provide its customer with a finished system.
“Everyone thinks the GT500 is different, but it’s not. The car is the same platform as a GT350 but has a blower. HPJ has shared the modifications they made with us and this kit’s going to be on the site so people can buy it,” he says.
Not only does Hellion have this kit available for GT500 cars, they’ll also be moving forward to offer a compound turbo kit that forces boost into the factory supercharger.
The HPJ team spec’d out a massive 6-inch intercooler to fit behind the bumper, which required them to cut the GT500’s brake ducts down to make room for the inlet and outlet to the cooler. Additionally, the intercooler bracketry needed to be modified to fit correctly. The transmission line and cooler mods finished off the major changes to the Hellion kit.
One item specifically gave them fits, and it wasn’t what you might expect given the build’s complexity. It seems that Ford changed the harmonic damper bolt specification on the GT500. When coupled with the length dimensions required to drive the oil pump that comes with the Hellion system, the team at HPJ found themselves searching for an M14x1.5 200mm-long bolt, which sparked a 2-day parts chase to every nut and bolt manufacturer in the country with no success. Ultimately, a call to Hellion Power Systems bore fruit, as the bolt they needed is the same as what Hellion provides in its Dodge Hemi turbo system kits that require ATI dampers.
This installation is not something the average garage builder would have easy success with; Stroud says the transmission lines are a big concern.
Additionally, they had difficulty adapting a Coyote-style throttle body to the car as no tuner has successfully developed a tune file as of yet. This car utilizes a Plazmaman Coyote billet intake manifold, and the HPJ team designed a billet adapter plate to use the stock GT500 throttle body.
With a pair of 64mm Precision turbochargers controlled by Turbosmart wastegates and blowoff valves, this insane twin-turbo GT500 dropped 1,103.2 rear-wheel ponies and 869.3 lb-ft on the HPJ dyno with Lund Racing on the tune, all done with the stock long-block. That’s some serious power.