The Fiat 500C Abarth: Turbocharged Cabrio Performance
The Fiat 500C Abarth, North American version, was unveiled in November 2012, at the Los Angeles Auto Show. With turbocharged engines made in Michigan, the 500 Abarth will be made in Mexico by Chrysler alongside other Fiat 500 models.
Fiat 500 Abarth turbocharged engine
Under a red cover, the turbocharged engine is coupled to a stronger five-speed manual transmission, equal-length half-shafts to avoid torque steer, a 3.35 final drive ratio, a 6,500 rpm redline, and a torque transfer control system. 0-to-60 mph times are in the “low 7 second range.”
The engine uses a standard cast-iron block, with an aluminum bedplate. Bore is 72 mm (2.83 inches) and stroke is 84 mm (3.31 inches) for a total displacement of 1368 cu. cm (83.5 cubic inches), smaller than any engine built by Chrysler in North America. The bottom end is toughened with a forged steel crankshaft, and select-fit main bearings supported across four main journals. The crankshaft has lightened counterweights to reduce overall mass for high engine rpm operation. Forged steel connecting rods have unique cross sections to reduce bending. Horsepower is 160 (as with Dart) but torque is 170 (while Dart is 184).
Full-floating piston pins add strength to the lightweight pistons, while cooling jets at the bottom of each cylinder squirt oil on the bottom of the pistons, cutting cylinder temperatures and reducing the possibility of hot spots along the cylinder walls or at the top of the piston that could lead to detonation. Noise is reduced and weight saved with a structural aluminum oil pan. As with the ordinary Fiat 500, the engine uses MultiAir (see 1.4 engines page).
The compression ratio is 9.8:1; the engine can run on regular but premium is preferred. The engine takes four quarts of oil, synthetic 5W-40 recommended, with oil change intervals are set at 8,000 miles. Coil-on-plug ignition fires dual-tip spark plugs. Fuel injectors spray at the intake valves.
The Abarth engine boosts output to an estimated 160 horsepower largely because of its turbocharger, which spins up to 230,000 rpm, forcing extra air into the cylinders; it normally runs at 210,000 rpm. The system uses two charge air coolers (commonly referred to as intercoolers) behind the driver- and passenger-side air inlets; these reduce the heat of the high-pressure air, allowing for higher air density and reducing the potential for engine knock. Observers say boost peaks at a whopping 18 psi, far higher than past Chrysler limits.
To go along with the extra power is a fresh-air intake system with high-flow air filter, improved-flow air box, and smoother-flowing plumbing. A concentric “double tip” dual-exhaust system reduces exhaust gas restriction, boosting power.
An Abarth-tuned powertrain control module (PCM) integrates all of the MultiAir Turbo’s engine control functions, with specific engine calibrations for “Sport” mode; it syncs with the LED-illuminated shift light for additional driver notification at the redline.
An upgraded electrical system includes a high-output 140-amp alternator and 500 amp cold-cranking maintenance-free battery for increased vehicle system charging.
The Fiat 500 Abarth’s C510 transmission includes an intermediate shaft with equal-length half shafts to mitigate torque steer. Compared with the Fiat 500, the 500 Abarth uses 23 percent larger half shafts (28.1 mm diameter vs. 22.8 mm diameter in the Fiat 500) for strength and reduced torsional stress.
Larger constant velocity (CV) joints with 53% greater torsional strength (2600 N•m vs. 1700 N•m in the Fiat 500) deliver added durability.
The torque-traction control system in the 2012 Fiat 500 Abarth has a differential locking system that uses the mechanical differential in the C510 transmission to control torque via the electronic stability control (ESC) system. Utilizing ESC enables the 500 Abarth to transfer torque from a front wheel that slips, to one that grips. When the Fiat 500 Abarth is in “Sport” mode, TTC automatically adjusts the degree of differential locking depending on dynamic factors, including speed.
Fiat 500 Abarth body, suspension, and brakes
Compared with the Fiat 500c, the Abarth has 23% larger half shafts (28.1 mm diameter vs. 22.8 mm); and larger constant velocity (CV) joints with 53% greater torsional strength. Both front and rear suspension were retuned, with 33% stiffer front spring rates, 15 mm lower ride height, revised lower control arms, a camber change (-1.5°), and dual-valve frequency selective damping KONI twin-tube struts. In back, the 500C Abarth has, compared with 500C, strengthened coil-spring supports; a 22 mm solid rear stabilizer bar; and 12% stiffer rear springs.
The Abarth version also has 10% quicker steering with a different power steering calibration, and a road crown and cross wind compensation algorithm, which automatically compensates for temporary situations where there is a constant push of the car to one side or another. It has higher performance brakes with semi-metallic brake linings at all four corners, and 11.1-inch ventilated rotors for greater stopping power (up from 10.1-inch). Both front and rear brake calipers are painted red. The electronic stability control system (ESC) has a three-mode calibration tied into throttle control during cornering. Other changes include a revised front fascia, side skirts, wheels, a cloth-top-mounted spoiler, rear fascia, steering wheel, speedometer, and various cosmetic changes. An analog turbo boost guage is included, with a warning light that comes on just before redline.
Front seats hasve a one-piece design with large side bolsters, a racing-harness pass through, accent stitching around the perimeter, and integrated side-thorax air bags. The rear passengers’ upper seatbacks are raised and bolstered for added back support. Beats audio includes six speakers, an 8-inch dual-voice coil (DVC) subwoofer with trunk-mounted enclosure, and eight-channel amplifier with digital sound processing.
A standard Sport calibration increases throttle response; Normal mode limits torque in first and second gears. The stability control can be completely shut off.
The Fiat 500 Abarth is an A-segment (mini-compact) open-roof hatchback assembled in Toluca, Mexico. The in-line four-cylinder, liquid-cooled engine is around 83 cubic inches or 1368 ml (1.4 liters) in displacement. A timing belt is used with MultiAir controlling 16 valves, a single overhead cam, and hydraulic end-pivot roller rockers.
|Dimension||Specification (with manual transmission)|
|Horsepower||160 bhp (119 kW) @ 5,500 rpm (117 bhp/L)|
|Torque||170 lb.-ft. (230 N•m) @ 2,500-4,000 rpm|
|EPA gas mileage||28 city, 34 highway (31 combined)|
|Acceleration||0-60 in 7.x seconds|
|Fuel||87 octane acceptable, 91 octane required|
|Oil, coolant||4 quarts synthetic 5W40 and 4.6 quarts coolant|
|Forward gears||3.909, 2.238, 1.520, 1.156, 0.872|
|Reverse, final drive||3.909 reverse, 3.353 final drive ratio|
|Electrical||120 amp alternator; 500 CCA battery|
|Wheelbase, etc.||See standard Fiat 500|
|Length||144.4 inches (3.7 meters)|
|Height||59.2 to roof (1.5 meters)|
|Ground clearance||4.6 (104 mm)|
|Drag coefficient (cD)||0.352 with 16” wheels, 0.365 with 17” wheels|
|Weight||2,545 distributed 64/36|
|Fuel capacity||10.5 gallons (40 liters)|
|Brake swept area||193 sq in front, 153 rear|
|Steering||Rack and pinion, electric with different modes|
|Suspension||Front, MacPherson with stabilizer bar|
Rear, torsion beam with stabilizer bar
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