The Dr.Ing.h.c.F. Porsche AG offers the 911 Carrera RS 3.8 sports car in a limited special series. This two-seater, based on the 911 Carrera 2 (1993 model year), differs, however, in its greater displacement, output raised to 300 HP, eye-catching rear wing and completely reworked chassis setup. The RS 3.8 was developed by the Porsche Race Sport Department as the basis for a motor racing variant, the 911 Carrera RSR 3.8, which can compete for the German ADAC GT Cup, for instance.

Engine reworked from the ground up

In order to match a displacement increase of this six-cylinder boxer engine from 3600 to 3800 cubic centimeters with an accompanying output gain, it was necessary to rework the entire unit from the ground up. Cylinder bores were expanded from 100 to 102 millimeters. With stroke unchanged at 76.4 millimeters, this produced a displacement increase of 200 cubic centimeters.

Despite their larger diameter, pistons of the RS 3.8 engine are lighter than those of the 3.6 liter base engine (1993 model year). This reduction in mass was achieved by further optimizing and lower piston height. Rocker arms, produced by an elaborate fine casting technology, are also lighter. Finally, the valves also underwent further work. Vibration dampers on the crankshaft are adjusted in dimension to the new demands. A double oil cooler ensures safe lubrication and cooling, at all times, even under extreme loads.

A new Motronic unit takes over timing of ignition and fuel metering in the RS 3.8. This Bosch-developed system with the identifying number 2.10 applies the very latest available technology. Among other things, this means active knock control which permits further map optimization and thus even better use of fuel and power production. The RS 3.8 is laid out to use fuel of "Super Plus" quality (98 octane RON).

Changes in air routing to the engine and in the exhaust tract are extensive and all-embracing. The air filter unit was optimized with the goal of confronting the gas flow with minimum possible resistance. Intake manifolds with enlarged passages now use six individual throttle flaps which ensure best possible cylinder filling for every revolution and load realm, in conjunction with sequential fuel injection.

Hot-film technology, which produces no measureable resistance to alr flowing in, is used in the 3.8 liter engine for airmass measurement, an important parameter for engine control. The goal of reducing exhaust back pressure was met in redesigning the exhaust system. This too required a basic new technical concept. The exhaust system of the RS 3.8 consists of a package including two catalytic converters and two tail pipes.

Compared to the former Carrera 2/4, output of the Carrera RS 3.8 increased from 250 HP (284 kW) at 6100 RPM to 300 HP (221 kW) at 6500 RPM. Torque also demonstrates a clear increase. It now peaks at 360 newtons at 5250 RPM, compared to 310 newtons at 4800 RPM for the Carrera 2/4. Rev-dependent engine cutoff occurs at 7100 RPM.

The five-speed, manual gearbox in the Carrera RS 3.8 offers short shift movements, to the benefit of rapid shifts. The flywheel was weight-optimized. Power transmission to the driveline is handled by a single-plate, dry clutch. Higher force and torque are balanced by increased spring pressure. The rear-axle differential has a lockup effect of 40 percent, under load and on overrun.

Sporting chassis tuning with a comfort component

Chassis tuning of the 911 Carrera RS 3.8 is oriented to the demands of drivers with sporting ambitions. That means: firmer layout of springs and shock absorbers with altered spring rates and gas-pres sure shocks from Bilstein. Engineers at the Porsche Race Sport Department, however, were also deeply involved in achieving a comfort component. Thus the RS 3.8 proves outstanding for long-distance trips as well as city traffic. Doing without servo steering for weight reasons alters nothing in these all-around properties.

Stabilizers for both axles are a factor in chassis optimization of the RS 3.8. The front stabilizer has a diameter of 24 millimeters and adjusts to five positions. The rear stabilizer of 21 millimeter diameter offers three adjustment positions. A brace between the front shock towers sees to additional driving stability under load extremes.

Stronger brakes

Hydraulic brake servo is used for the brake system. Four-piston, aluminum fixed-saddle brakes front and rear operate on vented and cross-bored brake discs. Front brake elements are the same as those in the 911 Turbo 3.6, the rear units come from the racing version of the 1992 model-year Carrera RS. Brake saddles are coated in red as an optical indication of the performance potential of this ABS-controlled brake system.

The Carrera RS 3.8 travels on tires with the dimensions 235/40 ZR 18 (front) and 285/35 ZR 18 (rear). Tires are mounted on three-piece Porsche Speedline rims (9 x 18 in front, 11 x 18 in the rear). Dunlop and Pirelli tires have been approved. Weight-reduction measures have reduced the car's weight to only 1210 kilograms (1140 kg without fuel). The tank with a capacity of 92 liters is a standard fitting.

More output with lower weight naturally provides clearly improved performance. The achievable top speed of the Carrera RS 3.8 is approximately 270 km/h. The speed of 100 is reached from a standstill in 4.9 seconds, 200 in only 16.6 seconds.

Optically the Carrera RS 3.8 differs from other variants in the 911 range chiefly for its large rear spoiler which carries the script imprint RS 3.8 on its side. This 911 Carrera RS 3.8 is built by hand in the Porsche Race Sport Department, Weissach.