Officially, the spiritual successor to the fabled McLaren F1 supercar is the Speedtail - the third car in McLaren's Ultimate Series. But of course, a large number of car fans will tell you that the title truly ought to go to the forthcoming Gordon Murray Automotive T.50. Designed by Gordon Murray, the legendary Formula One race car designer whose ingenuity was instrumental in developing the McLaren F1, the GMA T.50 has two big very big things in common with the F1 that the Speedtail does not: a naturally aspirated V12 engine, and a manual gearbox.

Now, that V12 has just been fired up for the very first time, as the T.50's development driver, Dario Franchitti shows us in the video below.

Housed in 'George', the first T.50 developmental mule, the Cosworth V12 engine fires up for the first time. For now, the 4.0L Cosworth GMA V12 is limited to just 4,500 rpm, although by the time it's ready for production, that redline will be raised nearly three-fold, to 12,100 rpm. That's twice as fast as many production engines, and it will help the diminutive V12 achieve a peak power output higher than the McLaren F1's 6.1L mill: 654 horsepower vs. 618. We would, of course, give just about anything to hear the Cosworth GMA powerplant spin up to that speed, but for now, its idle sound will have to suffice.

Apart from letting us hear the holy grail of modern engine designs for the first time, the video also gives us an update on where Gordon Murray Automotive is at with the car. The machine in this video is lightyears from production-spec, with an Ultima chassis serving as the basis for the powertrain test mule. Fun fact: the F1 also made use of Ultima-based test mules, whose names were "Albert" and "Edward."

With this test startup now in the bag, the test mule will soon be heading to the emissions labs at Millbrook, and then on to Italy's Nardo Ring, Spain's IDIADA test track, and a few other common locations for development.