Marking its 25th anniversary this year, the Ariel Atom has been part of the automotive landscape long enough to potentially overlook its awesomeness. Ariel is reminding us with a version even more extreme, featuring more power than any previous Atom. It’s named the Atom 4RR.
Developed to commemorate the Atom’s 25 years, the 4RR revolves around a significantly enhanced Honda K20C 2.0-liter turbo-four. Similar to the engine utilized in the latest Civic Type R and Integra Type S, it produces 525 horsepower and 405 lb-ft of torque in its most spirited engine map, with options for 500 hp/331 lb-ft and 400 hp/280 lb-ft available as well.
Ariel achieved this power by altering or upgrading nearly every component. The 4RR engine features closed-deck sleeves, custom forged pistons and connecting rods, modified cylinder head and port configuration, alloy valves with enhanced springs and guides, new camshafts, a larger turbo generating 1.7 bar of peak boost, and 1,400-cc fuel injectors to support it. The engine breathes through a carbon fiber intake reminiscent of an F1 car and exhales through a titanium exhaust system, while a gated oiling mechanism and high-flow pump ensure lubricant circulation under demanding track conditions.
Power reaches the rear wheels via a Quaife six-speed sequential transmission with pneumatic paddle shifters. The clutch is only necessary for initial movement, and there’s an auto-blip feature for downshifts. This, combined with a mere curb weight of 1,474 pounds, enables the 4RR to accelerate from zero to 62 mph in 2.4 seconds and to 100 mph in 5.1 seconds, making it the fastest Atom production model in Ariel’s lineup. Its top speed is 175 mph.
The iconic Atom exoskeletal chassis is equipped with adjustable twin-tube Öhlins dampers. Stopping power is provided by AP Racing two-piece ventilated rotors clamped by four-piston calipers, featuring driver-selectable ABS with 11 settings (including “off”). The 12.2-inch rotors are the largest that fit within the Atom’s staggered (16-inch front, 17-inch rear) wheel dimensions, which are shod with Yokohama A052 tires sized 195/50R16 in the front and 255/40R17 in the rear.
Carbon-fiber side pods have been designed with additional cooling channels for both the engine and gearbox, building on the ones created for the Atom 4R. An impressive rear wing and other aerodynamic components and mud guards (while it is primarily track-focused, Ariel asserts that the 4RR is still road-ready) are also crafted from carbon fiber. Stylish 25th anniversary graphics complete the look.
In Ariel’s native market, the Atom 4RR has a price tag of 208,000 British pounds, translating to approximately $280,000 at current exchange rates, contingent on Ariel reserving any production slots for the U.S. Vehicles will be built to order in “extremely limited numbers,” as stated by the company, but hopefully, there will be sufficient availability.
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**The Ariel Atom 4RR: A Street-Legal Kart with 525 Horsepower**
The Ariel Atom 4RR represents an extraordinary engineering accomplishment that blurs the boundaries between a conventional sports car and a go-kart, offering an exhilarating driving experience. With a featherweight chassis and a potent engine, the Atom 4RR emerges as one of the most exciting street-legal vehicles currently available.
**Design and Construction**
The Ariel Atom 4RR showcases a minimalist aesthetic that prioritizes performance over comfort. Made from a mix of aluminum and steel, the Atom’s chassis is both lightweight and sturdy, weighing roughly 600 pounds. This low mass is essential for attaining high performance, enabling the vehicle to accelerate swiftly and handle exceptionally. Its open-wheel design not only adds to its kart-like look but also improves aerodynamics and driver visibility.
**Engine and Performance**
At core, the Atom 4RR houses a supercharged 2.0-liter four-cylinder engine generating an impressive 525 horsepower. This power-to-weight ratio ranks among the highest in the automotive sector, allowing the Atom to sprint from 0 to 60 mph in slightly over 2.5 seconds. The engine pairs with a six-speed sequential gearbox, delivering fast and precise gear shifts that enhance the driving experience.
The Atom 4RR features sophisticated suspension systems, including double-wishbone setups at both the front and rear, ensuring outstanding handling and stability. The adjustable dampers enable drivers to fine-tune ride quality and handling dynamics according to their preferences, whether on the racetrack or city streets.
**Driving Dynamics**
Experiencing the Ariel Atom 4RR is unlike any other. The open cockpit design and absence of a standard windshield establish an immersive connection between the driver and the road. The vehicle’s lightweight nature and robust engine deliver prompt feedback, making the driver feel perfectly synchronized with the machine. The Atom’s nimbleness and responsiveness make navigating sharp turns and winding paths a pure delight, reminiscent of go-karting but with significantly greater power.
**Street Legality and Usability**
In spite of its racing credentials, the Ariel Atom 4RR is street-legal in numerous locations, permitting enthusiasts to relish its performance on public roads. However, prospective buyers should note that the Atom’s minimalist construction means it lacks some of the amenities and comforts present in traditional sports cars, such as complete enclosures, air conditioning, and ample storage. This makes it more aligned with individuals who emphasize performance and driving excitement over day-to-day practicality.
**Final Thoughts**
The Ariel Atom 4RR is a distinctive vehicle that merges the thrill of a go-kart with the power and performance of a premium sports car. With its light build, powerful engine, and remarkable handling, it provides an unmatched driving experience for enthusiasts. While it may not be the most practical option for everyday driving, for those in search of an adrenaline-pumping ride, the Atom 4RR is a standout choice that excels in every aspect.