The 2019 Chevrolet Corvette ZR1 doesn’t go on sale until spring 2018, but the tuners at Hennessey have already revealed a trio of upgrades for the car, including one that turns what was already Chevrolet’s most powerful production vehicle into a 1,200-horsepower beast.

That means Hennessey’s engineers have found a way to extract another sports car’s worth of power from the ZR1’s LT5 engine; in stock form, that supercharged 6.2-litre V8 already makes 755 hp. The upgrade also adds 351 lb-ft of torque, for a total of 1,066 lb-ft.

Interestingly, while Chevrolet’s Dubai introduction of the car came with just one performance statistic — a 338-km/h top speed — Hennessey has released a full slate of stats for its version of the car. Those include a 2.2-second zero-to-96 km/h (zero-to-60 mph) sprint; a 9.2-second 236-km/h quarter mile; and a top speed of more than 370 km/h.

As you might guess from the amount of power they add here, Hennessey exercised little restraint in creating its ZR1 package. Aluminum pistons and forged steel connecting rods hook up with a stroker crankshaft that expands displacement to 7.0 litres.

The cylinders are fed by a high-flow supercharger and air-to-air intercooler, through ported cylinder heads and an upgraded valvetrain, while spent gases are extracted through stainless steel headers and mid-pipes and high-flow catalytic converters to keep the car emissions-legal.

In case all of that sounds too extreme for you, Hennessey has two other packages for the ZR1, including an HPE1000 package good for an even 1,000 hp and 966 lb-ft of torque (2.5 seconds zero-to-96; 9.7-second 1/4 mile); and an HPE850 setup that boosts horsepower to 850 but leaves the stock 715 lb-ft torque figure alone. Hennessey says it’s good for a 2.6-second acceleration sprint and a 10.3-second quarter-mile time.

Notably, this trio of packages are all about performance: Hennessey mentions no cosmetic or aerodynamic mods, suggesting the company is confident the ZR1’s chassis setup is up to managing the extra power.

For all three upgrades, Hennessey says the power figures are measured at the crankshaft, with actual output — measured at the wheels on a dynomometer — coming in at 15 to 20 percent lower.