Ariel Atom 4RR, a 527 hp beast built for the track but also road-legal

When we think of lightweight sports cars that can be a mountain of fun on the track but that, once the track day is over, can be driven legally back on the road and even on winding mountain roads, two brands should inevitably come to mind, and both are British: Caterham and Ariel.

The first was in the spotlight a month ago thanks to the presentation of an exclusive limited edition, and the second, Ariel, is the one we are looking at today, as it is currently celebrating the 25th anniversary of its most representative model, the Atom. As you already know, the concept of the Ariel Atom is to offer us a sports car in which shaving kilos off the scales is the main goal; everything is seasoned with quality components and a powerful engine, giving us the perfect recipe for very enjoyable track days. And what’s better, it is road-legal too.

The celebration of this anniversary is very special for Ariel, as they demonstrate with the launch of the Atom 4RR, a version that is custom-built and optimised for track use, where it will move like a fish in water, but be warned, because true to its philosophy the Atom 4RR will also be homologated for use on open roads. In addition, every future owner of the Atom 4RR will enjoy a unique experience, as they will be invited to Ariel’s factory in Crewkerne to define their ideal Atom, since each one will be manufactured to unique specifications and built to order.

The Ariel Atom 4RR draws attention thanks to the aerodynamic package it receives, making it quick through corners and very stable at high speeds. It borrows solutions from the Atom 4R, such as the carbon fibre side pods, but redesigned to add greater cooling to both the engine and the gearbox. The bodywork itself as well as the front and rear wings and the mudguards are made of carbon fibre and, beneath these, forged 16-inch wheels are fitted on the front axle and 17-inch on the rear, with Yokohama A05 tyres.

Beneath this striking attire lies the most evolved chassis ever fitted to any Atom, working together with elements such as fully adjustable twin-tube Öhlins dampers, machined aluminium mounts, suspension arms and adjustable chromoly pushrods. Braking is handled by new AP Racing two-piece 310 mm ventilated discs, using four-piston AP competition calipers, in combination with ABS adjustable across 11 levels from inside the cabin.

Mechanically, the heart of the Atom 4RR remains the robust and reliable KC20 block of original origin, specifically from the Civic Type R: a four-cylinder, 2.0-litre unit which, for this model, has almost all of its important internal and external components replaced, including closed-deck liners, custom forged pistons and connecting rods, revised cylinder head and port geometry, bespoke camshafts and an alloy valvetrain with reinforced springs and guides, not forgetting a larger turbo to reach 1.7 bar of boost pressure. All of this is to raise its power to a brutal 525 hp and 550 Nm of torque, transmitted to the rear axle through a six-speed Quaife sequential gearbox. These figures allow it to accelerate to 100 km/h in a brilliant 2.4 seconds and reach 160 km/h in just 5.1 seconds, which, combined with its mere 700 kg of weight, results in a power-to-weight ratio of more than 780 hp per tonne.

As you can see, the Ariel Atom 4RR is a truly impressive vehicle, and because of this it becomes something almost exclusive. In fact, its price will be a luxury for a select few, since if you want to get your hands on one you will have to part with at least £208,000 plus taxes, which is where its price starts.