Ruf CTR - History

History

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 hp (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 choose 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; most of the CTRs produced were converted from existing customers' Carreras.