Ariel is celebrating 25 years of its Atom spaceframe sports car with the launch of the new 4RR, its most powerful version to date.
The upgraded Honda four-cylinder engine delivers an impressive 525 hp (391 kW) and 550 Nm (406 lb-ft) to the rear axle, making this special edition even more potent than the wild 475 hp (354 kW) Atom V8 from 2011.
Although Ariel hasn’t shared official performance figures yet, the standard Atom 4R, which the 4RR is based on, has 400 hp (298 kW) and manages 0 to 100 km/h (62 mph) in just 2.7 seconds.
The 4RR is expected to come in close to the 680 kg kerb weight of the 4R, resulting in a staggering power-to-weight ratio of 770 hp per tonne. This could see the sprint time drop below 2.5 seconds, making it one of the fastest-accelerating combustion-engine cars to come out of Britain.
Ariel will build just 25 units of the track-focused special edition to order, with full technical details to follow later this year.
The brand says the 4RR has been developed so that “the most serious track drivers can explore the limits of the lightweight Atom while utilising the full extent of their driving skills.”
Despite evolving significantly over four generations and 25 years, the Atom remains visually and structurally similar to the original.
The first-generation Atom featured the company’s signature tubular spaceframe chassis and a 120 hp (89 kW) Rover K-series engine, while the Mk2 moved to the Honda Type R engine still used today. A supercharger option arrived in 2005, pushing power to 275 hp (205 kW).
Power was increased to 300 hp (224 kW) with the Atom 3, which brought a new chassis, suspension and bodywork, as well as the hardcore Atom V8.
The current fourth-generation car, which underpins the R and RR, is almost entirely new aside from the fuel filler cap, steering wheel and pedals. It switched to turbocharging as standard and produces 320 hp (239 kW) even in its base form.