Tony O'Kane | Apr 13, 2016

Hennessey's Venom GT Spyder, the low-production, twin-turbo, V8-powered, Lotus-bodied American supercar, has smashed the world record for "world's fastest convertible" previously held by the megadollar Bugatti Veyron Grand Sport Vitesse.

While the topless Bugatti was able to muster up a scalp-whipping 408.84km/h top speed with its roof stowed, the Venom GT Spyder has soundly beaten it with a 427.44km/h top speed.

But with a monstrous 1082kW coming from its 7.0 litre twin-turbo V8 compared to "just" 882kW from the Grand Sport Vitesse's 8.0 litre quad-turbo W16, the Venom's power advantage gives it a substantial edge in straight-line speed.

Then again, the Bugatti has seven gears in a slick-shifting dual-clutch transmission and all-wheel drive. The Venom GT makes do with a six-speed Ricardo manual and rear-wheel drive.

The feat was announced as part of Hennessey's 25-year celebrations, with company founder John Hennessey describing it as "a special way to celebrate 25 years of making fast cars faster".

"I’ve wanted to test the top speed of our Venom GT Spyder, without the roof, ever since our coupe ran 270.4 mph on the Space Shuttle landing runway at NASA’s Kennedy Space Center in 2014.

"This was a great way to validate the technical excellence of our carwhich includes high-speed stability with an open roof", Hennessey said.

To further celebrate its 25th anniversary and capitalise on its latest world record, Hennessey will offer just three "World Record Edition" Venom GT Spyders at a cool US$1.3 million (AU$1.7m).

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