Gordon Murray T50: Ultima-based mule lets V12 rip in new video

As the Gordon Murray Automotive T50 supercar is prepared for launch, test driver Dario Franchitti has taken to the high speed bowl at Millbrook Proving Ground in an Ultima GTR-based prototype, giving us an early taste of its distinctive engine note.

In an official video (below), the four-time Indycar Series champion gets acquainted with the T50's Cosworth-developed 650bhp naturally aspirated V12 as he prepares to drive one of the production-bodied XP (experimental prototype) test cars.

This is our first opportunity to hear the 4.0-litre V12 at speed, and as Franchitti approaches the headline-bating 12,100rpm rev limit, the engine note has obvious echoes of the twelve-cylinder power units used in Formula 1 until 1996. 

As was the case with the McLaren F1 (also developed by Gordon Murray and widely regarded as the T50's spiritual forebear), this test mule, known as George, is based on an Ultima, which is usually powered by a Chevrolet-derived V8 and as such has had to be extensively modified to accomodate the larger engine.

Three functioning XP cars are in operation, however, and one will star at the Goodwood Member's Meeting next week, lapping the Sussex circuit in anger in what will be the T50's public debut. 

The biggest mechanical difference between George and the final production car is that the early prototype goes without the T50's trademark downforce-enhancing fan technology. Inspired by the device used by Brabham's 1978 F1 race car, this essentially creates a 'virtual long tail' when the car is running at high speeds, improving stability. 

Notably, the Ultima's cabin also features a conventional two-seat layout, whereas the final T50 will adopt an F1-style three-seat arrangement, with the two passengers positioned slightly behind the centrally located driver.