In producing the F355 Berlinetta, Ferrari developed a brand new 3.5-litre V8 engine, capable of producing 375bhp at 8,250 rpm. The new engine’s maximum torque capability was 268 lb/ft at 6,000rpm, with a specific output of 109bhp per litre.
The engine featured an aluminium block with wet steel liners coated in Nikasil, and Formula 1 technology was evident in the presence of the titanium alloy con rods driving the crankshaft. The most innovative feature of all was the F355’s five valves per cylinder (3 intake and 2 exhaust), combining high rev capability and high intake permeability. In accordance with the F355’s racing design, Ferrari’s engineers produced a compact, high-swirl combustion chamber, with a compression ratio of 11:1. Engine control was provided by a Bosch Motronic M2.7 electronic injection, static ignition setup.
Exhaust insulation was provided by stainless steel, boasting twin-branch catalyst delivery: the first branch feeding a ceramic matrix catalyst, and the second, by-pass branch feeding steel matrix catalysts. This second branch is only used at higher speeds, and responds to the Motronic system’s opening of a throttle valve. This technology optimises performance by lowering exhaust back pressure.
Enhanced transmission technology
In terms of its drivetrain, the F355 Berlinetta boasted a 6-speed transmission, with the option of adding F1-style paddle shifters operating an electro-hydraulic gearbox. The manual, synchronised setup offered short movement through the traditional Ferrari gated shifter with rigid rods for a high-performance feel. The gear ratios were designed with the F355’s torque curve in mind, improving the driveability of the car, as well as its sporty performance. The car featured a multi-plate limited-slip differential, as well as a hydraulically-actuated single dry plate clutch housed in magnesium alloy. The water-oil heat exchanger ensured that the oil in the gearbox was maintained at prime operating temperature.
The Formula 1 electro-hydraulic transmission developed by Ferrari made its debut on the F355 and signalled a new age for drivetrain engineering and performance. The driver is in control of a sequential system, with paddles situated behind the steering wheel as in F1 cars, with no clutch pedal. There are four operational modes which the driver can select: “sport”, “normal”, “auto” and “low grip”. This system guarantees almost instant gear changes, with no need for the removal of the driver’s hands from the wheel, even during tight cornering at high speeds. For safety reasons, however, it is not possible to engage intermediate gears at the same time as rapid downshifting. The entire system can be switched to automatic mode with little impact on fuel consumption. Furthermore, the software controlling the gear shift system is fully integrated with other systems within the F355 Berlinetta, ensuring optimal control in ever-changing driving conditions.
© 2006 Martin Hemmings and Bobby Wong for www.sport-cars.org
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