1990 Ruf BTR C4 Lightweight

By the time the 1980s were coming to a close, Alois Ruf's German firm had been granted full manufacturer status by the German government, and they were no longer just a mere Porsche tuner. The Ruf BTR (Gruppe B Turbo RUF) was the first product from the German tuner to be offered with a company-specific VIN. Production began in 1983 and was based on the Porsche 911, available in both the narrow or optional wide-body configuration. Production continued into the late 1980s with around 20 or 30 examples built. Power was sourced from the 3.4-liter, flat-6 turbocharged engine and tuned to produce around 370 horsepower. A five-speed manual gearbox was standard with a six-speed becoming an option in 1988. Other modifications were made to the suspension and brakes. Inside were Recaro leather seats, Ruf instrument clusters and steering wheel, and a Simpson race harness. Body modifications included a front spoiler with an oil cooler, optional Porsche 935 style wing mirrors, and Ruf 5-spoke 17-inch alloy wheels.

Among the company's accolades were its record-breaking 211 mph CTR 'Yellowbird', and its status as the largest company to make Porsche performance enhancements

In 1988, Porsche introduced the most sophisticated 911 ever, the 964, which they touted as being 85% new as compared to its predecessor, the Carrera 3.2. The 'Carrera 4' models had an all-wheel-drive system while the 'Carrera 2' variants had rear-wheel drive. Both variants were offered as a coupe, Targa, or Cabriolet. Power was sourced from a naturally aspirated flat-6 engine with a 3.6-liter displacement. The previous torsion bar suspension was replaced with coil springs and shock absorbers, and power steering and ABS brakes were added to the 911 for the first time - both as standard equipment. The new electric rear spoiler would raise as speeds in excess of 50 mph; below 50 mph, it lowered down flush with the rear engine lid.

The 3,600cc all-aluminum alloy six-cylinder engine had dry-sump lubrication, electronic fuel injection, seven main bearings, and delivered 247 (SAE) horsepower at 6,100 RPM and 310 Nm of torque.

RUF's bespoke modifications significantly enhanced the already impressive specification of the 964, with output from the engine increasing to 425 bhp thanks in part to the addition of a turbocharger. A Sachs-supplied RUF electronic clutch system and RUF Type R6450 gearbox did away with the conventional clutch pedal, resulting in faster shifting. The brakes were upgraded to cope with the increase in power, and the suspension was stiffed to ensure that it could tackle corners at increased velocities.

Among the list of body modifications were a widebody kit, low-profile racing mirrors, and a whale tail. The interior received a RUF-designed 'concealed' roll cage, visible only when the doors are opened. Lightweight glass for all windows reduced weight, as did the simpler door cards, and the removal of the rear wiper and all door electronics and insulation.

The performance management features can be disengaged with the twist of a knob. There is an AWD adjustable knob for the driver to change the four-wheel bias when in the rain or when racing. The ABS can be disconnected by a knob on the dash.

by Daniel Vaughan | Jul 2019