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The 2015 Alfa Romeo 4C vehicle dynamics


Utilizing technologies and materials derived from Formula 1 and supercars, the all-new 2015 Alfa Romeo 4C is designed to be powerful and ultra-lightweight. The Alfa Romeo 4C demonstrates its performance credentials with a top speed of 160 mph (257 km/h), 0-to-60 mph acceleration reached in the mid-4 second range, 1.1 g of side acceleration on corners and 1.25 g of maximum braking deceleration.

The Alfa DNA selector with “Race” mode

The Alfa Romeo 4C features the brand’s Alfa DNA selector – enabling the driver to choose among four driving modes. With a touch of the Alfa DNA selector, the character of the Alfa Romeo 4C can be changed to (in order of increasing capability):Alfa DNA control

  • All-weather – designed to ensure maximum control under adverse weather conditions, this mode enables the Alfa Romeo 4C to respond gently to accelerator input. The anti-slip regulation (ASR) system selects special engine and brake control logic and, in the event of loss of grip, modifies power to prevent skidding or loss of traction
  • Natural – this mode enables the Alfa Romeo 4C to deliver grand touring features. The Alfa TCT gearbox utilizes an “auto-up” function when engine speed approaches the rev limiter. The Alfa Electronic Q2 differential operates more passively, only engaging if one of the rear wheels loses grip
  • Dynamic – in this mode, the Alfa Romeo 4C provides the driver with improved driving performance. A more aggressive powertrain calibration enables the engine to be more responsive, while the Alfa TCT gearbox delivers 25 percent quicker gear changes. Additionally, the electronic stability control (ESC) system is less intrusive, enabling the driver more lateral drift before intervening
  • Race – is the most extreme performance mode, putting the driver in total control of the car under race conditions. ESC is deactivated and only intervenes to prevent loss of control during fierce braking. ASR is also deactivated, allowing the driver to control traction through the accelerator pedal. Alfa Electronic Q2 differential control system remains active for fast exits out of corners or bends

For driving convenience in Dynamic, Natural or All-weather modes, the Alfa TCT gearbox can utilize an “auto” mode.

Lightweight vehicle architecture

To create the lightweight architecture needed for maximum performance and dynamic efficiency, Alfa Romeo engineers designed a monocoque chassis made entirely of carbon fiber. The engineers utilized “pre-preg” technology – a formulated heat-cured resin matrix system that features reinforced manmade carbon fibers. Additionally, Alfa Romeo 4C’s “pre-preg” monocoque features carbon fiber that runs in the same “unilateral” direction enabling it to be five times stronger than conventional materials that are “isotropic,” or have the same strength in all directions. The result is a monocoque formed around the driver and passenger that delivers high stiffness and strength. Attached to the Alfa Romeo 4C’s monocoque are front and rear cell structures, roof reinforcements and an engine mounting frame made from lightweight aluminum.

Alfa Romeo 4C lightweight structure

On the exterior, the Alfa Romeo engineers created the bodywork entirely of SMC (Sheet Molding Compound), a low-density, high-strength composite material that is 20 percent lighter and dimensionally more rigid than steel. Providing the ability to create complex shapes while saving weight by 20 percent compared to steel are PUR-RIM (injected polyurethane) fascias and rear spoiler.

Alfa engineers optimized the Alfa Romeo 4C’s windshield and side windows by using 10 percent thinner glass and a 4 mm thick windshield to reduce weight by up to 15 percent.

Last, two sport seats feature a carbon fiber and fiberglass structure reinforced-composite to deliver the strength and seating position needed for performance driving.
As a final result, the coupe features the high torsional stiffness and strength characteristics, as well as optimized center of gravity, which gives the advantage of increased agility and drivability.

Double wishbone and MacPherson suspensions

The front suspension is comprised of a “superimposed” double wishbone configuration. At the rear, an advanced MacPherson suspension is used. Both front and rear suspensions are made from aluminum and high-strength steel. For the North American market, the all-new Alfa Romeo 4C is designed with stiffer springs, larger front- and rear-sway bars, and re-tuned shock absorbers.

Alfa Romeo 4C suspensions

Steering, braking and wheels of the Alfa Romeo 4C

The Alfa Romeo 4C exclusively removes the conventional power steering system altogether. Through a manual steering system and 15.7:1 quick-ratio steering, the Alfa Romeo 4C provides the driver with maximum feel-of-the-road. Furthermore, an appropriate steering-wheel load is maintained thanks to the low overall weight of the car.

To deliver maximum stopping power and 1.25 g of braking deceleration, this Alfa Romeo is equipped with four self-ventilating perforated discs and Brembo four-piston aluminum calipers at the front axle.

Both the standard 17-inch front and 18-inch rear, or the optional forged 18-inch front and 19-inch wheel and tire combinations feature a larger rear wheel to deliver improved handling.

Source: Alfa Romeo
Romain’s opinion:

The technical choices made in this car are quite radical. I believe that Alfa Romeo is targeting the Lotus Elise with its 4C in terms of performances and customers. They applied the famous Lotus mantra: Light is right. Do you think that they will manage to reach the selling price of the Lotus Elise? Will they manage to reach good volumes of sales despite the fact that it is a niche segment?

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