Two days ago, we told you about a special version of the Caterham Seven that sported a RS Performance 2.4-liter V8 producing over 500 horsepower in a 1000-pound body. That's insane. It's hard to imagine anything moreso, in fact, than a car producing more than 1000 horsepower per ton, right?

Wrong.

Enter the Ariel Atom 500, a limited edition of the latest Atom chassis that's available with the same engine as the Caterham. Developing over 500 horsepower at 10,000 rpm, the tiny V8 is an all-aluminum engine with dry sump lubrication and five valves per cylinder. The engine is mated to a six-speed Sadev transmission with paddle shifts and both launch and traction controls. The Atom chassis features unique twin air intakes, cabron fiber panels and spoilers, and Alcon four-piston brakes behind Dymag magnesium(!) wheels.

Prices haven't been finalized yet, but the engine alone has a retail price tag of £115,000 ($226,000) — plenty enough to put a dent in the piggy of even the hardest-core enthusiast.

Ariel announce the latest version of the Atom - the Ariel Atom 500, powered by a small V8 engine. With over 500bhp in a 500 kilogram package, the Atom 500 will boast one of the highest power to weight ratios ever for a production car, ever. At over 1000bhp per tonne the Atom 500 will be the ultimate statement in performance and is destined to be made in a limited edition.

The V8 powered Atom is the first of some exciting developments from Ariel due to be released though 2008 and builds on the growing reputation that the company has for putting the passion back into driving and producing cars that are fun to drive as well as fast both on and off the track.

The 500 started life as a one off special project with RS Developments in 2007 and features the Russell Savory designed 2.4 liter V8 engine coupled to a 6 speed sequential Sadev gearbox. Developing over 500bhp at 10,000rpm the supercharged engine features all alloy construction, 5 valves per cylinder and a dry sump. The gearbox will have flatshift capability, a paddle gearchange with manual override as well as launch and traction controls.

Recognisable by the twin rear intakes for intercoolers the Atom 500 will feature a unique colour scheme for chassis, wheels and bodywork combined with carbon fibre panels and carbon fibre aerofoils. Other features will include chromemoly aerofoil wishbones, integrated function steering wheel, Alcon 4 pot caliper brakes and Dymag magnesium wheels.

Said Simon Saunders, Director of Ariel, '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 what is achievable in a road registered car. We also use this sort of project to explore the possibilities of how we can improve our standard cars. The Honda engined production cars already combine all the elements that we want in an Atom and by pushing the envelope to these sorts of extremes we can further improve the breed'.

The Atom 500 will be produced in Somerset at the new Ariel factory with the first car available from Spring this year. Prices have not yet been finalised but Ariel's commitment to performance for value will ensure that the Atom 500 is competitive in cost as well as performance.

With the standard Atom 300 already achieving sub 3 second times to 60mph and sub 7 second times to 100mph, the 500 will take this one stage further with record breaking production car possibilities.