Up against supercar giants such as Ferrari, McLaren, Lamborghini and Bugatti, Hennessey Performance came up with the Venom GT as a speed-demon contender hypercar in 2010. Now, for their 25th anniversary, Hennessey took the Venom GT Spyder variant for a run to check its open-top speed, and hit a record breaking 265.6mph peak, beating the 254.04mph record for the Bugatti Veyron Super Sport Vitesse.

Unfortunately, the record isn’t official, even though the speed was independently verified by Racelogic Vbox. Guinness only considers cars as valid production cars if more than 30 identical examples can be built. Still, it’s quite an underdog victory for a car that was built off a Lotus Exige, with a bit of extra American engineering knowhow. On the other hand, the Bugatti Veyron was a car that cost billions of euros and 10 years of development.

This phenomenal speed for the Spyder comes from its 7-liter turbocharged V8. The car was driven down the runway by Brian Smith, the director of Ford Performance’s Driving School. It’s only 5mph slower than the hardtop Venom GT. This achievement will be celebrated with Hennessy building three World Record Edition models of the hypercar, each with a $1.3 million (plus tax) price tag.

Although we can be sure that a future version of the Bugatti Chiron will have something to say about this, for now, you can catch the thrill of the moment in the video below.