Power alone could never deliver the superb performance of the Alfa Romeo 4C. An advanced transmission system is needed to control it.
The functioning logic of all electronic systems has been optimised to obtain exactly the right level of performance for the driving conditions. You can change the character of your 4C with the touch of a finger: docile and prudent (All weather), balanced but sporty (Natural) or fast and aggressive (Dynamic). The Alfa Romeo DNA selector has offered three driving modes since 2008. On the Alfa Romeo 4C, the system has been thoroughly revised to respond to the needs of a high performance supercar.
The three existing modes have therefore been supplemented by a fourth: Alfa Race.
Alfa Race is most extreme performance mode, and is engaged by moving the mode selector to Dynamic position and holding it there for a few seconds. Alfa Race mode puts you in total control of your car under race conditions. By minimising the interventions of electronic systems, it leaves you, the driver, in complete command.
In Alfa Race mode, ESC stability control is normally deactivated and only intervenes to prevent loss of control under harsh braking. ASR is also deactivated under acceleration and braking, leaving you to control traction through the accelerator pedal alone. Alfa’s Q2 differential control system, on the other hand, remains active, as it is essential to permitting fast exits from bends.
Dynamic mode configures the car to deliver great driving performance. Engine control parameters are configured to respond instantly to accelerator input and the Alfa TCT gearbox selects a rapid action program to reduce gear shift times by up to 25%. The ESC system permits a certain angle of drift and only intervenes if steering wheel position and drift angle could put the car at risk.
Natural mode is designed for everyday use. Gear shift parameters are configured for maximum comfort and smoothness. In manual mode, the Alfa TCT transmission makes up for loss of driver concentration. The Auto-Up function shifts up to the next gear when engine speed approaches the permitted limit, while the Auto-Down function shifts down as soon as engine speed falls below 1000 rpm. Finally, the Alfa Q2 differential operates in soft mode and only cuts in if one of the rear wheels suffers a significant loss of grip.
All Weather mode should be selected to ensure maximum safety under adverse weather conditions.
In All Weather mode the car responds to accelerator input very gently. The ASR system selects special engine and brake control logic and, in the event of loss of grip, modifies power to match road speed and prevent skidding that could otherwise be difficult to control.
The 4C is equipped with an Alfa TCT 6-speed transmission with dual dry clutch, a solution that combines the instant power of a sequential shift with all the convenience of an automatic. This system works like two gearboxes in parallel, each with its own clutch. The next gear is selected while the previous gear is still engaged, eliminating all discontinuity in power transmission.
The Alfa TCT clutch has been specially modified for use on the Alfa Romeo 4C. The 4C’s special clutch features all-new control software that ensures the fastest possible gear shifts under all conditions. Gear shifts are more aggressive in the sporting performance modes, and drivers can clearly feel the new gear engaging, as on a racing car. On bends, on the other hand, gearshifts are completed in the smoothest way possible to avoid reducing stability. The 4C is also fitted with Launch Control for easy high performance standing starts. Launch Control is activated by pressing the brake pedal while pushing the accelerator pedal all the way down and squeezing the paddle on the left of the steering wheel. As soon as you release the brake, the system automatically controls the gearbox, traction and power to maximise acceleration.
The Alfa Romeo 4C’s advanced scavenging technology maximises torque at low engine speeds and delivers more power in response to driver input. The control unit determines valve overlap times and angles with great precision to create a through-flow of air from the inlet manifold to the exhaust manifold.
To complement the scavenging technology, the engine is also equipped with a new generation turbocharger and a pulse converter exhaust manifold that exploits pressure waves to boost torque at low engine speeds. The manifold and the turbine are made from microcast steel.
Like all top competition cars, the 4C uses an automatic cool-down system to protect its turbocharger. Switching off the engine would normally cause the immediate stoppage of oil circulation, leaving the oil in the turbocharger to stagnate at very high temperatures. The thermal stress suffered by the oil in this way causes a loss of lubricating capacity and also leads to the formation of residues that can damage the engine. To prevent this, Alfa Romeo has introduced an after-run pump. This electric pump is automatically controlled by the ECU and keeps oil circulating through the turbocharger until it has cooled sufficiently.