Ariel has redesignated its 2027 Atom 4RR as the most powerful model in the lineup, producing 525 horsepower from a completely reworked Honda Civic Type R K20C turbo four-cylinder engine. The roughly 1500-pound British track car costs £208,000 in the U.K., estimated at around $325,000 in the U.S., more than double the price of the 400-hp 4R model.
The engine rebuild takes roughly 100 hours and includes forged connecting rods and pistons, closed-deck sleeves, revised cylinder head with improved camshafts and valve springs, and a larger turbocharger running 25 psi of boost. The result delivers 406 pound-feet of torque at 5200 rpm. Two softer engine maps provide 400-hp and 500-hp options alongside the full 525-hp tune.
An exclusive new distribution deal with Forman Motorworks opens all Ariel models to U.S. buyers, with deliveries planned to start next summer. Previously, only select lesser Ariel models had been available stateside under a licensing arrangement.
The 4RR's chassis tuning was overseen by race driver and former Top Gear Stig Phil Keen. Manually adjustable Öhlins dampers allow a softer inboard, pushrod-operated suspension. The car runs 12.2-inch AP Racing brakes with four-piston calipers and wears Yokohama A052 track-oriented tires in 255 section at the rear.
Despite its extreme power-to-weight ratio and 525-hp output, the car exhibits composure on road surfaces, refusing to be unsettled by midcorner bumps and handling suspension compliance through its reworked damping setup. The Quaife six-speed sequential transmission responds tractably to gentle clutch input. Traction control and ABS are fully adjustable through multiple stages, including fully off. Estimated performance includes 0-60 mph in 2.3 seconds and a top speed of 175 mph.