Pfaffenhausen adopts a carbon tub, reverts to rear-engine
Ruf aims to light up the world’s supercar stage in Geneva by unveiling of its fourth generation CTR range-topper, which is billed as the world’s first carbon-fiber monocoque car to be driven by a rear engine/transaxle powertrain. The car is aimed at purist adherents to Alois Ruf’s “analog performance” philosophy, which favors the mechanical simplicity of a low weight-to-power ratio, a manual gearbox, rear-wheel drive, a minimalist interior, and proper needle-gauge instruments.
Ruf Automobile GmbH has been repairing, modifying, perfecting, remanufacturing, and riffing on Porsches from its home base in tiny Pfaffenhausen, Germany since the birth of the 911 in 1963. Its first CTR (which originally stood for Group C, Turbo Ruf), the 1987 “Yellow Bird,” featured aero-optimized 911 bodywork and an enlarged 3.4-liter twin-turbo engine conservatively rated at 469 hp and 408 lb-ft. It hit 60 mph in 4.0 seconds and ran the quarter in 11.7 at 133.5 mph (215 km/h) on its way to a 211-mph (340 km/h) top speed. Ho-hum numbers in 2017; they were the shizzle in 1987. A 993-generation CTR2 followed in 1995, but in celebration of Yellow Bird’s 20th anniversary, the third-generation CTR3 moved to a dedicated mid-engine platform powered by a 691-hp/660-lb-ft 3.8-liter flat-6 force-fed by two KKK turbos. Subsequent upgrades boosted output to 767 hp/720 lb-ft.
As CTR turns 30, this fourth-generation car launches with a tamer, more tractable 3.6-liter twin-turbo flat-six that cranks out an even 700 hp and 649 lb-ft or torque bolted to a newly developed six-speed transaxle driving the rear wheels only. Ruf lists the “dry weight” of the new CTR at 2,640 lb (1,197 kg), so figure about 3,100 (1,406 kg) with full fluids, or about 4.4 pounds-per-horsepower. That about matches the 918 Spyder’s (a car from the far opposite end of the analog-digital performance philosophy spectrum). That output is sufficient to launch the car to 62 mph in (a traction-limited) 3.5 seconds en route to a 225-mph (362 km/h) top speed, says Ruf.
Suspension is by control arms and pushrod-actuated coil-over shocks at all four corners, and this marks the first time Ruf has had complete control over the entire chassis design. Naturally there are vented and perforated carbon-ceramic brakes all around, with 15.0-inch front discs clamped by six-piston calipers and 9.8-inch discs and four-piston calipers in the rear matching the whoa to the go. The brakes are framed by 19-inch forged wheels wrapped in tires measuring 245/35ZR19 in the front and 305/30ZR19 in the rear.
Interestingly, the suspension and powertrain are carried by lightweight steel crash structures front and rear that bolt to the carbon-fiber monocoque tub. The roof-crush roll-cage structure is also made of steel. Alois Ruf claims that this solution ended up lighter and more compact than making these structures out of aluminum would have been. The overall weight of the new CTR is less than that of the CTR3.
Vehicle dynamics experts might question the wisdom of reverting from a mid-engine layout to a rear-engine one, on grounds that it worsens the polar moment of inertia and hence makes the car less eager to turn into a corner, but there’s no denying that the proportions made possible by this arrangement allowed Ruf to better pay homage to that original 911-based Yellow Bird CTR. (And in any case, the more extreme CTR3 remains available for purchase—but only three more will be built.) All body panels are in carbon fiber.
Production is expected to begin during calendar year 2018 at a price of 750,000 Euros ($792,500 USD). It is available in the U.S. by direct sale from the factory.