John Hennessey and his Hennessey Performance shop down in Texas are on a mission to bestow everything with more power, and the latest vehicle in their sights? The Rolls-Royce Cullinan. “We’ve got a client with a Cullinan who wants to speed it up, so we’re going to take that to the 850-horsepower range,” Hennessey told Robb Report.
The Rolls-Royce SUV comes stock with a twin-turbocharged 6.7-liter V-12 that’s good for 563 horsepower and 627 lb-ft, but because it’s an engine that’s forced induction, Hennessey says his crew of research and design specialists already know just how to massage the extra horses in there. “Anything that’s naturally aspirated, it’s so much harder to get the additional power that it’s not worth your cost or time,” he says. “But we feel confident about the Cullinan. It’ll be a future package we offer.”
As for the client, “this guy’s a successful potato farmer from Wisconsin,” Hennessey says. “We do a six-by-six Chevrolet Silverado truck called Goliath. We get the tune on the supercharged 6.2-liter V-8 up to about 700 horsepower and that thing hauls. He loved it and got one of those. And when he got his Cullinan, he flew down to see us, on his private jet, and proposed we work on the Cullinan. We say no to lots of things, but that’s one we said yes to,” Hennessey laughs.
It’ll be interesting to see how Hennessey handles the exhaust. The Cullinan has little engine noise so the cabin can remain relatively quiet. We’re wondering if it’ll get a full exhaust swap that’ll add some grunt. Regardless, watching the Spirit of Ecstasy blur by on the prow of a Hennessey Performance Cullinan will be a fun sight.