Ferrari 456M GT & GTA Drivetrain

The 456M engine is designed to get high power and torque at low and medium rotational speeds, from a smaller, lighter package. The V12, 65° engine, with its 436bhp required no major modifications, but Ferrari engineers still improved its function for the purpose. The ignition order has been changed for smoother operation enhancing overall comfort. The new firing order is 1-7-5-11-3-9-6-12-2-8-4-10. The crankcase, heads and oil sump are in light alloy, with added aluminum liners.

Valve timing is controlled by four overhead camshafts. There are two intake and two exhaust valves per cylinder, arranged at a very sharp angle. The intake runners have a rectilinear form and the combustion chambers have a low surface:volume ratio for greater efficiency. The lubrication system has two scavenger pumps and one delivery pump, double filtration and a radiator. A duct sprays oil directly on the underside of each piston for improved cooling.

A Bosch Motronic M5.2 system controls ignition and fuel delivery. Injection is multi-point, timed, and sequential, with bi-angular spray pattern and special throttle control. The fuel supply system includes two submersed pumps with compact filters. Ignition is static, with two six-outlet coils. The system includes a static stroke sensor and a toothed wheel on the engine flywheel.

Transmission:

The 456M GT manual transaxle is at the rear. The hydraulic clutch acts directly on the engine flywheel. Drive is transmitted to the gearbox through a three-bearing driveshaft housed in a steel pipe rigidly connecting engine and gearbox. The six-speed-plus-reverse box has double-cone synchronizers with a low-friction direct sixth gear. The transmission is pressure lubricated with a pump and oil radiator. The gearbox control features the Ferrari standard aluminum gearshifter and polished aluminum gate. The differential is a ZF, fin-type, with limited slip and differentiated calibration.

The 456M GTA automatic transmission has 4 electronically controlled gears, and like the manual unit it is integrated with the differential for unrivaled weight distribution. The 456M GTA transmission housing is hydraulically attached to the strengthened chassis, and the driveshaft housing has been stiffened. The V12's power and flexibility combine with the calibration of the hydraulic torque converter to ensure unparalleled performance in an automatic 2+2. The GTA transmission is managed by twin computers in the transmission and Bosch Motronic M5.2 system monitoring parameters such as the throttle position, the accelerator control speed, vehicle speed and engine speed. The multiple logic transmission ECU continuously identifies the best settings for the car. The driver can also intervene directly whenever he wishes to take complete control.