Hennessey Performance Engineering has been gifted a mighty title for its birthday.

Taking to a Texan Navy base’s airstrip last month for its 25th anniversary, the American tuner wound out its latest creation, the Venom GT Spyder, to a world-record snaring 427.4km/h.

Revealed last year, the Spyder is a pop-roof version of the regular Venom GT. Lying behind Brian Smith, the man who piloted the record run, was the car’s twin-turbo 7.0-litre LSX V8 that produces 1082kW and 1745Nm. Crazily, its power’s channelled through a six-speed ’box to the rear wheels only.

Hennessey Venom GT Spyder rear driving

The Spyder steals the record from Bugatti’s Veyron Gran Sport Vitesse, which claimed to be the world’s fastest convertible after hitting 408.84km/h Volkswagen Group’s proving grounds in Ehra-Lessian, Germany, in 2013.

Hennessey claims World's Fastest convertible record
Hennessey Venom GT Spyder’s front

Three examples of the “World Record edition” Venom GT Spyder will be built. At an eye-watering price of US$1.3 million before tax.