Its 563kW and 969Nm is able to be pumped up with one of three engine upgrades for the 6.2-litre LT5, the highest of which Hennessey estimates could put the ZR1 in the low 9 second range for the quarter mile.
But starting at the lowest level, called HPE850, the Corvette will still get a boost to 633kW while retaining its original 969Nm. This is done through a series of changes such as high-flow cylinder heads, stainless steel headers, a lower pulley upgrade, and a Hennessey camshaft upgrade.
Hennessey estimates this level of upgrade could hit 97km/h (60mph) in 2.6 seconds, and run a 10.3s quarter mile.
HPE1000 is where even bigger power gains come in, as well as a boost in torque. The ZR1’s outputs become 746kW and 1310Nm, Hennessey claims, which bring its performance figures to a claimed 9.7s quarter mile and 2.5s 0-97km/h sprint.
This is achieved through an upgraded high-flow supercharger, a Hennessey camshaft, ported cylinder heads, high-flow catalytic converters, and a high-flow air-to-air intercooler upgrade amongst other changes.
The final, and most powerful of the upgrades, is the HPE1200.
A frankly ridiculous 895kW and 1445Nm are claimed to come from the now 7.0-litre supercharged V8, as well as custom aluminum pistons, forged steel connecting rods, stroker crankshaft upgrade, and other upgraded replacement parts.
0-97km/h is a claimed 2.2 seconds, with a quarter mile in 9.2s.
While the lower two upgrade packs come with a two-year or 24,000 mile warranty, the HPE1200 come with one year and 12,000 miles.
Hennessey says production for the upgrade is limited to 100 units, though didn’t specify whether that applies to each level of upgrade, or the Corvette upgrade series overall.