Hennessey Venom GT has unofficially claimed the title of the world's fastest sports car having reached a record speed of 270.49 mph at the Kennedy Space Center, earlier this month.

The battle to retain the fastest car title continues. For the records, Bugatti Veyron Super Sport still holds the title of "World's Fastest Production Car" in the Guinness World Records, but a recent achievement by the Hennessey Venom GT unofficially puts the American sports car on top of the charts. The Bugatti Veyron Super Sport holds the title with a top speed of 269.86 mph, which is lesser than Hennessey Venom GT's newly accomplished 270.49 mph.

If the recorded speed by Hennessey Venom GT is higher than that of Bugatti Veyron Super Sport then why is it not official? The speed test was done at the Kennedy Space Centre in Florida, earlier this month. The 3.2 mile-long space shuttle landing runway was approved by the NASA for the Venom GT to make just one run, which does not meet the Guinness World Records guidelines. According to the record-holding company, a car must make two runs in opposite directions to qualify for the title.

Another reason for the record to be unofficial is the car maker's decision to make only 29 Venom GTs and it has completed 11 so far. This violates one of Guinness' guidelines, which requires at least 30 cars to be built for it to qualify as a production model, John Hennessey, the company's founder and president,  told BBC's Top Gear. But Hennessey is confident that if the runway was longer, about a mile at least, the Venom GT could have crossed 275 mph or reached even 280 mph.

Driver and former Michelin tyre test engineer Brian Smith echoed Hennessey's strong predictions about Venom GT's power to achieve higher speed. "At the very top end, there was a little wandering, but hey, we're going 270mph!" Smith said. "It was still pulling. If we could run on an eight-mile oval, we could go faster than that..."

Bugatti's record was nearly dismissed after Hennessey Performance claimed that Bugatti had deactivated a 258 mph speed limiter to set the record in violation of Guinness official guidelines in April. But Guinness found that the adjustment did not affect  Bugatti's design or engine, so decided not to strip Bugatti of its title.

The Hennessey Venom GT, which starts at a base price of $1.2 million, is powered by a powerful 7.0-litre twin-turbocharged, v8 engine, capable of producing a horsepower of 1,244 bhp. It can accelerate 20mph to 120mph in just 7.71 seconds. Every car is custom-ordered and takes six months to build.

Watch the video below showing Hennessey Venom GT clock 270.49 mph.