The '640' in the Ultima GTR640's name refers to power output, 640 horsepower. And because of the combination of a lightweight chassis and an extremely powerful engine, the GTR640 has set several speed records.
In July 2006, a 720 horsepower Ultima GTR, the GTR720, set four new speed records for a road car. In road going form, with road tires, it set the fastest 0-60 mph time (2.6 seconds), the fastest 0-100 mph time (5.3 seconds), the fastest 100 mph - 0 time (3.6 seconds), and the fastest 0-100 mph and back down to 0 again (9.4 seconds).
This puts the Ultima GTR720 ahead of legendary supercars like the Mclaren F1, Ferrari Enzo, Porsche Carrera GT and Pagani Zonda F for accelaration and breaking performance.