Ferrari 348 Drivetrain

The 348 was powered by Ferrari's 3405cc V8, introduced with the car in 1989. The 90° light alloy V8 had 10.4:1 compression and 48 valves actuated by four overhead camshafts. It produced 300bhp at 7200rpm and 237lbs-ft at 4200rpm in the 348 tb, ts, GTB, GTS and Spider models. Changes to the exhaust system gave the 348 Serie Speciale 312bhp at 7200rpm. The V8 was installed longitudinally in the 348, bolted along with the transmission and rear suspension into the removable tube-steel rear sub-frame, a significant innovation.

The new block had a revised basic geometry. It featured a five-main bearing crankshaft and nikasil-steel cylinder liners surmounted by heads with revised geometry and centrally mounted spark plugs for a high efficiency, high volume, high speed flow for spark and combustion efficiency. The valves were actuated through bucket tappets by dual overhead camshafts. A dry sump lubrication system provided necessary lubrication under all conditions. A pair of side-mounted radiators cooled the engine.

Fuel was delivered from the center mounted tank to the intake runners through fuel injectors by a high pressure pump. Air was delivered from the high side scoops through articulated rubber and steel tubes to a filtered square airbox above the transmission and from there through twin throttle bodies to the intake manifolds situated above the engine. An advanced Bosch Motronic M2.5 fuel injection and ignition system controlled delivery and spark until 1993 when the M2.7 replaced it. Exhaust gasses flowed through a steel manifold and a tuned exhaust system with catalytic converters.

Power was transmitted from the flywheel to the rear wheels through the clutch, gears, final drive and constant velocity joints. The new transmission was mounted across the rear of the engine in the style of pre-turbo Formula 1 racing Ferraris. The clutch sat at the rear of the drivetrain. The new configuration sited the entire drivetrain four inches lower in the chassis than had the previous model.

The transverse arrangement of the five-speed cable-actuated gearbox gave the initial models their names: tb for "trasversale berlinetta" and ts for "trasversale spider." The 1993 revisions saw the gear ratios shortened for better acceleration without affecting terminal speed. Along with the new transmission came a revised clutch situated at the very rear of the engine bay. Combined with the hydraulically actuated dry clutch, a "bimass" flywheel was able to damp secondary vibrations in the drivetrain.