Hennessey Performance Engineering straps a lot of high-performance cars to its dyno, but the McLaren Senna is in a league of its. We say that because the Senna is an all-out track monster with 789 horsepower and a dry weight of just 2,641 pounds.
That makes for a lovely power-to-weight ratio, and it turns out the ratio is even better than the official numbers suggest. HPE loaded a Senna onto its dyno for some baseline numbers and the results showed McLaren may be sandbagging on its official power figures. After the pull, which looked and sounded far less dramatic than we'd imagined for a car of this caliber, the readings showed this particular Senna makes 724 hp at the wheels. Based on the quoted numbers, that represents about an 8 percent drivetrain loss, which is below the typical loss of 10-15 percent. Even on the low end of the spectrum, it could mean the Senna makes closer to 800 hp, if not up to 832 hp.
There's also the matter of torque, which McLaren rates at 590 pound-feet. The dyno showed the supercar makes 627 lb-ft and that's with the drivetrain loss. We'd definitely like to see a few other runs to see if the torque figure remains consistent. Dynos are, after all, not the best way to brag to friends about power numbers.
We'll never likely know if McLaren is purposely underreporting the Senna's numbers. However, way may see if HPE can pull even more power out of the British supercar. We have a feeling the Texas-based tuner will have no issues cranking the twin-turbo 4.0-liter V-8 past 1,000 hp, especially with these baseline figures. The company didn't mention what it has in store, but the typical round of HPE upgrades seems likely.