No sane person could think that the existing supercharged version of the Ariel Atom is lacking in urge but the Somerset-based sportscar maker has decided to raise the bar regardless, with a V8-powered version of its skeletal roadster. The 500 refers to both the supercharged 2.4 litre V8 engines claimed power output of 500 bhp and the target weight of 500 kilograms. Which, to spare you the maths, translates as a power-to-weight ratio of 1000 bhp / tonne. Both power and weight figures are identical to those claimed by Caterham for its forthcoming supercharged Levante. Unsurprising, as it turns out as the Ariel shares the same Russell Savory developed motor as the Caterham. The bike-derived V8 engine weighs just 90 kg and produces peak power at a dizzy 10,000 rpm. Drive is delivered through a sequential gearbox controlled by paddle shifters. The Atom 500 will also feature both launch and traction control. The 500 will be distinguished from lesser Atoms by major twin air intakes for the intercoolers, plus a gold colourscheme for the wheels, chassis tub and bodywork. Vast carbonfibre wings sit at each end and will be capable of producing serious aerodynamic downforce. No performance figures or targets are have been released yet, but the 300 bhp Atom Supercharged blitzed all competitors in last years 0-100-0 challenge. According to Ariel boss Simon Saunders, the 500 should be substantially quicker and is clearly targeted at breaking records: This is an interesting project for us and an experimental departure from what we normally produce. For a few customers the Atom 500 will be the ultimate expression of lightweight performance and represents the outer limits of whats achievable in a road-registered car. The Atom 500 will go on sale in the spring. Prices have yet to be finalised, but Ariel promises it will be competitive on cost as well as performance.