The 2020-2022 Shelby GT500 is an incredible machine right off the showroom floor, thanks in part to its supercharged, 5.2-liter Predator V8 engine. For some owners, however, incredible is just the beginning. Ray Rich of DRP Motorsports took a 2021 GT500 that came into his shop completely stock and turned it into a 1,000-rear-wheel-horsepower monster, all thanks to a few carefully chosen parts and a custom tune.

The project began as DRP Motorsports replaced the factory supercharger with a larger 3.8-liter Whipple unit. To handle the switch to E85 fuel, they also installed a set of Injector Dynamics ID1300X fuel injectors. Rich emphasized just how simple the hardware changes were. The “car is all stock other than what you see right here,” he explained, noting that the car retains its factory exhaust manifolds, factory catalytic converters, and factory cat-back exhaust.

On the dyno, the results were stunning. The car’s baseline run in stock form produced 723 rear-wheel horsepower. After the Whipple, injectors, and DRP’s E85 tune, the numbers jumped dramatically. “We made 1,001 wheel horsepower and 755 lb-ft of torque,” Rich announced.

Peak power was achieved right around 8,000 rpm, which is incredible given the stock dual fuel pumps. Rich admitted is “testing the limits with this setup on E85.” He noted that while the air/fuel mixture was safe, the fuel pressure started to drop slightly at the top of the rev range, suggesting a fuel pump voltage booster would be the next logical step for sustained high-rpm use.Ray also addressed the common question of upgrading the Whipple versus porting the stock blower. While a ported factory unit can make big power, he explained that at a certain point, “You are pushing the limits of the factory rotor pack.” In contrast, the 3.8-liter Whipple at this entry-level boost setting is “not breaking a sweat at all,” with the potential for 1,200 to 1,300 rear-wheel horsepower when paired with the proper supporting mods.

This build demonstrates the incredible potential lurking under the hood of the latest Shelby GT500s, and it highlights how critical custom tuning is to safely unlock that power.