The twin-turbo Ruf CTR (Group C, Turbo Ruf) also known as the CTR Yellowbird or simply Yellowbird, was a limited-production, high performance sports car produced by Ruf Automobile of Germany.
Introduced for the 1987 model year and based on the Porsche 911, the CTR featured an enlarged and highly tuned version of Porsche's 3.2 litre flat-six cylinder engine, lightened body panels, an integrated roll cage (adding chassis stiffness in addition to occupant safety), upgraded suspension and braking systems, a custom-designed transmission, and several unique trim pieces such as polyurethene bumpers, and the use of the fender-mounted oil filter (a Porsche feature for the 1972 MY only) necessitated by relocating the oil tank forward to clear the intercooler on that side.
Much attention was given to aerodynamic considerations, with the body being de-guttered/seam welded and the use of filler panels for the door pillars and 935-style mirrors. Prototype models had NACA-style intercooler intake ducts over the rear fenders (later dropped, as it was discovered that air was pulled out, rather than in, at speed due to a low-pressure area), while later models had additional slots in the rear bumper corners for the air to exit.
Ruf rated the car 469 bhp or 469 PS, not making a distinction between the units. It is said that 469 horsepower was the lowest dynamometer reading of all the CTR engines tested while the average ﬁgure was closer to 500 or even higher. Ruf would later admit that ‘we use very big horses in Pfaffenhausen’.
Developing understated 469 bhp (350 kW) and 408 lb·ft (553 N·m) of torque and weighing in at only 2,535 pounds (1,150 kg), the CTR provided stellar performance, with a 0-60 mph time of 3.65 seconds and a top speed in excess of 210 miles per hour (340 km/h). Although the Porsche 959 was faster to 60 miles per hour (97 km/h), the Yellowbird could outperform all competition when it came to top speed, topping out at 213 miles per hour (342 km/h), a top speed that made it the fastest sports car in the world at the time of its release.
The car received its nickname, "Yellowbird", during testing by Road & Track magazine, whose staffers noted the contrast created by its yellow paintwork against the overcast skies on the day of their photo shoot.
The Ruf CTR had its first appearance in April 1987 at the "World's Fastest Cars" contest of the American car magazine Road & Track where it was designated "The Fastest Production Car in the World". It did 0-60 mph (97 km/h) in 4.0s, 0-100 mph (161 km/h) in 7.3s, 0-124.3 mph (200 km/h) in 10.5s, 1⁄4 mile (402m) in 11.7s reaching 133.5 miles per hour (215 km/h) and reached a top speed of 211 mph (340 km/h), beating the competition by 10 mph (16 km/h). Paul Frère shouted "This is faster than I've ever gone in my life!" during a ride.
In 1988 Auto, Motor und Sport organized a high speed test at Nardò Ring where the Ruf CTR was the fastest reaching 342 km/h (213 mph), surpassing a Porsche 959 s (339 km/h (211 mph)), two Ferrari F40 (321 km/h (199 mph) each) and a Mercedes AMG 6.0 32V (288 km/h (179 mph)). At one point it achieved an unofficial 215 mph (346 km/h).
In 1989 test driver Stefan Roser drove the CTR around the Nürburgring. The laps were captured on camera and released by Ruf in a groundbreaking, enthralling, and influential video called "Faszination on the Nürburgring".
In 2004 an old Ruf CTR could keep up with new supercars at the Autocar 0-100-0 challenge and impressed the audience, so did another one - with more than 100,000 kilometers on its odometer - at the Road&Track standing mile contest 2005. Steve Millen's words after the drive: "That thing's a blast. It accelerates hard. It's a real old-school car with a lot of torque and power. Just awesome. What a rush. It pulled the whole way through."
The CTR (abbreviation of "Group C Turbo Ruf") was based on the 1987 911 Carrera 3.2 as opposed to the 930, Porsche's factory turbocharged version of the 911, a decision made because of the 3.2's slightly lower curb weight and drag coefficient. Factory body panels including the doors, hood and engine cover were replaced with aluminum pieces, helping to knock an additional 200 kg (441 lb) off the vehicle's factory curb weight. Shaved rain gutters to reduce drag, fiberglass front and rear bumpers and a pair of intake ducts on the rear flares to allow airflow to the intercoolers topped the list of body modifications. The rear arches were also increased in width very slightly to accommodate the larger speedline wheels.
In addition to the lighter panels, considerable modifications were made to the engine, including boring the cylinders out to 98 mm (3.9 in) to increase displacement from 3.2 to 3.4 litres, adding an uprated Bosch Motronic fuel injection system, and switching to the ignition setup originally designed for the Porsche 962 race car. A specifically designed turbo system featuring two large turbochargers and twin intercoolers topped the engine work, bringing total output to 469 bhp (350 kW) and 408 lb·ft (553 N·m) of torque at 5950 rpm. The sound from the blow-off valve was also curiously close to the chirp of a canary, helping the name "yellowbird" stick.
At the time, Porsche offered the 911 3.2 with a 5-speed manual transmission, but the 930 featured only a 4-speed transmission, chosen because it was the only unit manufactured by the company that could handle the turbocharged engine's high output. Not content with only four forward gears and unable to satisfactorily modify the 5-speed unit, Ruf chose to use a new five-speed transmission of their own design on the CTR, which also gave them full freedom to customize gear ratios. To ensure absolute control, an upgraded suspension system, 17 inch Ruf Speedline alloy wheels, 330 mm (13.0 in) diameter Brembo braking system, and Dunlop's Denloc system performance tires were used.
The company debuted the vehicle at the end of 1987 with pricing set at $223,000 per unit, although that number could vary depending on whether a given customer ordered their car directly from Ruf or brought in a unit purchased via dealer for conversion. Ruf made only 29 CTRs from chassis bought from Porsche; about 20-30 were built from customers' Carreras.3,367 cubic centimetres (205.5 cu in) twin-turbo sohc flat-6
Bore x stroke 98 x 74.4 mm (3.86 x 2.93 in)
Compression ratio 7.5:1
Power: 469 bhp (350 kW) @ 5950 rpm
Torque: 408 lb·ft (553 N·m) @ 5100 rpm
Redline: 6800 rpm
Weight: 1,150 kilograms (2,535 lb)
Specific output: approx. 137 hp (102 kW) per litre
Power-to-weight ratio: approx. 5.4 pounds (2.4 kg) per horsepower
Tyres: 215/45VR-17 front, 255/40VR-17 rear
Rear engine/rear drive
The CTR could generally outperform most other high performance cars of the time, including the Ferrari Testarossa and Lamborghini Countach. In addition, despite being slower than the Porsche 959 to 60 miles per hour, it could outperform the Porsche 959, Ferrari F40 and Lamborghini Diablo to 100 miles per hour and reach a considerably higher top speed.
It was also a highly competent track vehicle, and for several years the CTR held the unofficial lap record at the Nurburgring-Nordschleife track.
Test results by Autocar:0–30 mph (48 km/h): 1.69 s
0–60 mph (97 km/h): 3.65 s
0–100 mph (161 km/h): 6.71 s
0–150 mph (241 km/h): 14.59 s
0–200 mph (322 km/h): 35.57 s
Standing mile: 27.7 s @ 189.11 mph (304.34 km/h)
0–100-0 mph: 11.85 s
0–200-0 mph: 47.20 s
Test results by other magazines:0–100 km/h (62.1 mph): 4.1 s
0–200 km/h (124.3 mph): 10.5 s
Standing 1/4 mile: 11.7 s @ 133.5 mph (215 km/h)
0–1,000 m: 20.9 s
Top speed: 213 mph (342 km/h)
The CTR was succeeded in 1996 by the CTR2 based on Porsche's newer 993 Generation 911.
In the Wangan Midnight series, a character named Tatsuya Shima drives a black Ruf CTR Yellowbird, thus known as the Blackbird. Previous installments of the Wangan Midnight Maximum Tune series used a black modified Gemballa driven by Shima (Japanese only), but in the American and International releases, Shima's Gemballa is replaced with a black Nissan Fairlady Z (Z33). The CTR reappears in Wangan Midnight Maximum Tune 4, with the Blackbird once again being driven by Shima, before switching to the RCT later in the game. The Ruf CTR is also playable in Maximum Tune 4 with other Ruf cars. Another character, Kouichi Kijima drives the Ruf CTR Yellowbird demo car in one of the levels only in Maximum Tune 4, but in the anime it was a white Ruf CTR Yellowbird, which many fans refer to as the "White Bird". But the English subtitles reveal it is a Porsche 911.
The Ruf CTR is also a playable/drivable car in the video games "Project Gotham Racing 3", "Project Gotham Racing 4", "Driver: San Francisco", "Forza Horizon", "The Duel: Test Drive II", "Assetto Corsa", "Project CARS", and most of the "Gran Turismo" series games.