By John 
New dyno data is raising fresh questions about whether the latest Corvette ZR1 is delivering more power than its official factory rating suggests, potentially placing Chevrolet’s most extreme production car in an even higher performance bracket than advertised.
Automakers traditionally publish crankshaft horsepower figures, which are measured before drivetrain losses occur. Once power is routed through a transmission and driveline, wheel horsepower is typically lower. That expectation has fueled debate after Hennessey Performance tested a completely stock Chevrolet Corvette ZR1 and recorded a peak output of 1,050 horsepower at the wheels.
Chevrolet officially lists the Corvette ZR1 at 1,064 horsepower from the factory, a number that represents crank output rather than what reaches the pavement. Under normal conditions, drivetrain losses would reduce wheel horsepower well below that figure. The near-parity between the published rating and the dyno result suggests the actual crank output could be significantly higher, with estimates placing it somewhere between 1,100 and 1,200 horsepower.
During testing, peak power was achieved at 6,960 rpm, while maximum torque reached 821 pound-feet at 4,810 rpm. The engine tested was Chevrolet’s 5.5-liter twin-turbocharged flat-plane-crank V8, currently regarded as the most powerful engine ever installed in a production Corvette. No modifications were made prior to the dyno run, reinforcing the idea that the results reflect factory performance rather than aftermarket tuning.
On-track performance has further supported the ZR1’s reputation. The car has already established multiple benchmarks, including a 6:50.763 lap time at the Nürburgring Nordschleife. That time surpassed the lap set by the 815-horsepower Ford Mustang GTD, underscoring the ZR1’s performance credentials beyond the dyno room.
Pricing reflects the ZR1’s position at the top of the Corvette lineup. Chevrolet lists the ZR1 starting at $185,000, while the hybridized ZR1X begins at $209,700. Production limits have not been officially announced, though supply-chain factors could influence availability, particularly for the more complex ZR1X.
Determining the Corvette ZR1’s true crank horsepower may remain unresolved, but the dyno session establishes a clear baseline. For Hennessey Performance, known for extreme builds such as the 2,031-horsepower Venom F5 Evolution, that baseline is typically just the beginning of what follows.
Shawn Henry