2008 Chevrolet Cobalt SS
The new Cobalt sports a 2.0 liter turbo charged 4 cylinder engine, direct injection, 2 scroll Borg Warner turbo charger, forged crankshaft, and rods. It also has stainless steel intake valves with sodium filled exhaust valves. The LFN engine is a constant torque engine by varying the boost pressure of the turbo for a maximum 21 psi. The 5 speed transmission has an optional limited slip differential. And with 260 hp and weighing in at only 2900 lbs it’s sure to be a fun drive.
The new Cobalt sports two cool features in a car that stickers around $23K.
Launch Control: Hold down the throttle in sport mode and release the clutch. The car will make an ordinary driver look like a pro. I have not seen this in any car in the $20K price range.
No Lift Shift: Hold down the throttle between gear changes and release clutch. This allows the turbo to stay spooled between gears to reduce turbo lag. The car actually launches between gears. I believe the no lift shift may have cut at least .5 sec off the lap times.
2008 Chevrolet Cobalt SS
GM’s new turbo charged Cobalt is a blast to drive. It is the best bang for the buck in the low 20K range. You get a turbo charged front wheel drive car with launch control, stability control and no lift shift. I would opt for the limited slip differential. The stability control in the sport mode was fabulous. The car should easily hold 1 g. on the skid pad. The car was very nimble and with a good power range and minimal turbo lag on the track. Most front wheel drive cars would have a tendency to under steer when pushed past the limit of adhesion. The Cobalt was actually very neutral. There was a hint of under steer then the stability control would kick in and drag the rear brake and the rear end would begin to rotate around and give the driver a neutral feel. The engineers from GM told me that they designed the new turbo Cobalt “one step away from going for the kill.”
For street driving leave the stability control in normal mode and enjoy the comfortable race inspired seats which works great for daily driving and for the weekend warriors track events.
- 4 piston Brembo front brakes with 315mm front rotors
- 2 piston rear brakes with 292mm rear vented rear rotors
- Upgrade brake lines and pads
- Rims have been increased .5” with 225/40/18 tires
- New steering knuckle with larger bearings that is race ready to hold the load for track events
- Raised the roll center
- Decreased the steering arm length to reduce the steering ratio to 14.8:1 ( supercharged cobalt is 16.5:1 )
- Changed the front sway bar end links to reduce torque steer
- Front strut has stiffer spring rates with revised valving with increased low speed rebound and increase compression
- Stiffer rear stabilizer bar, and increase the rear spring rate
- Stiffer rear axle bushing from 55 to 65 durameter rubber
The Cobalt SS is powered by a turbocharged and intercooled 2.0L Ecotec DI engine that delivers 260 horsepower (194 kW) and 260 lb.-ft. of torque (353 Nm) with the standard five-speed manual transmission.
“Chevrolets are about fun and the SS models are the most fun of all,” said John Heinricy, GM Performance Division executive. “With the Cobalt SS, fun is balanced with a serious degree of capability, on both the street and racetrack.”
Features such as “no-lift shift” and other driver-selectable performance modes help the Cobalt SS achieve 0-60 mph in approximately 5.7 seconds and cover the quarter-mile in approximately 14.2 seconds, with minimal torque steer. The top speed is more than 160 mph.
2.0L Ecotec DI turbo engine details
The Cobalt SS’s Ecotec 2.0L turbo engine is the same that powers the recently introduced HHR SS. It produces 2.1 horsepower per cubic inch of displacement (130 hp / 97 kW per liter) and is the most powerful engine in the Ecotec family. Gasoline direct-injection technology helps the engine produce more power while maintaining lower fuel consumption.
With direct injection, fuel is delivered directly to the combustion chamber to create a more complete burn of the air/fuel mixture. Less fuel is required to produce the equivalent horsepower, especially at normal cruising speeds, of a conventional port-injection combustion system. Direct-injection technology works well with turbocharging and helps deliver a great balance of power and economy.
Highlights of the Cobalt SS’s Ecotec 2.0L DI turbo engine include:
- Steel crankshaft
- Forged connecting rods
- Oil-spray piston cooling
- 9.2:1 compression ratio
- Aluminum cylinder head with stainless steel intake valves and sodium-filled exhaust valves
- High-pressure engine-driven fuel pump
- Mobil 1 synthetic oil
Components including the steel crankshaft and forged connecting rods are high-strength items that provide strength and enhance durability. Oil-spray piston cooling helps reduce cylinder temperatures and promotes longevity by delivering pressurized oil that continuously lubricates the pistons, which reduces friction. To enhance combustion, the piston tops feature a dish shape that deflects incoming fuel toward the spark plugs.
To accommodate the direct-injection system, the Ecotec 2.0L DI turbo has a unique cylinder head and intake manifold. The cylinder head incorporates mounting locations for the fuel injectors – items that are typically mounted in the intake manifold on port-injection engines. Specialized and extremely precise multi-hole fuel injectors are used to meter fuel and deliver it in a finely atomized manner. They are supported by an engine-mounted high-pressure fuel pump.
Apart from the mounting positions of the fuel injectors, the cylinder head has conventional port and combustion chamber designs. Large stainless steel intake valves and sodium-filled exhaust valves are durable components designed to stand up to the high-performance capability of the engine.
The unique cylinder head, fuel system, pistons and intake manifold are the major components that differentiate the 2.0L DI turbo from other members of the Ecotec engine family. Mobil 1 synthetic engine oil is installed at the factory. Synthetic oil was selected for its friction-reducing capabilities and high-temperature performance.
Turbocharger and charge air cooler
Pumping up the Cobalt SS’s 2.0L Ecotec engine is an intercooled turbocharger system. The turbo blows pressurized air into the combustion chambers to enhance horsepower and torque, while the system’s intercooler circuit cools the turbocharged air charge to maximize its effect. The turbocharger is sized to deliver a significant horsepower boost and almost no spool-up lag. Maximum pressure is almost 20 psi.
Because the pressurized air pushed by a turbocharger becomes heated, the Cobalt SS’s system employs an air-to-air intercooling system. With it, the pressurized air passes through a heat exchanger mounted behind the grille in the lower front fascia, where it is cooled before it enters the engine. Cooler air is denser, enabling the combustion chambers to draw in more air for maximum power. The cooler air also staves off the possibility of detonation at higher temperature, which allowed engineers to tune the engine for maximum power and ensure consistent performance in all driving conditions.
Backing the turbocharged engine is a standard GM Powertrain Sweden F35 five-speed manual transmission. Semi-synthetic transmission fluid is used for its capability of absorbing heat and resisting breakdown during high-performance driving.
A performance-oriented feature referred to as “no-lift shift” allows maximum performance – upshifts can be performed very quickly without lifting the throttle. An algorithm in the engine’s controller enables this high-performance feature, which helps maximize acceleration and gear changes.
A short-throw shifter with stiffened shifter bushings and modified cables and attachments enhance confidence behind the wheel, giving the driver a firmer, more direct and quicker shift feel. A limited-slip differential is available with the manual transmission.
3.82:1 final drive ratio
The Cobalt SS’s powertrain has a 3.82:1 final drive ratio, which was selected because it allows the turbocharged engine to remain in the optimal section of the torque band during shifts and while driving competitively on a racetrack. This enhances both the car’s tangible performance measures and intangible fun-to-drive quotient.
The Cobalt SS is at home on the boulevard or starting grid, thanks to development at Germany’s famed Nürburgring racing circuit – a winding, undulated road course of approximately 14 miles in length (22 km) and with more than 170 turns. It is considered by many professional racers and auto manufacturers as the ultimate test of a car’s mettle.
In fact, the Cobalt SS set a lap record for front-drive sport-compact cars at the “’Ring,” posting a time of 8:22.85 minutes – besting the previous record by more than 13 seconds.
“The Cobalt SS delivers an integrated driving experience that balances a strong, satisfying feeling of acceleration with a precise, responsive chassis,” said John Heinricy, GM Performance Division executive. “It has been tuned to deliver confident handling and road manners, and drivers should find it very predictable in the corners of any racetrack.”
GM Performance Division (GMPD) is responsible for the “go, stop and turn” capability of Chevrolet’s high-performance SS models, and its team of enthusiastic engineers made sure that the new, 2008 Cobalt SS not only achieved stellar performance on the track, it delivered it with a grin-inducing level of driving satisfaction.
Specific performance features include:
- FE5 sport suspension
- Standard F35 five-speed manual transmission with short-throw shifter
- Quicker-ratio steering
- Brembo fixed-caliper front disc brakes
- Vented rear disc brakes
- Eighteen-inch wheels and performance tires
- Driver Information Center “Competitive” mode with launch control function
- Available limited-slip differential
Conveying the Cobalt SS’s turbocharged horsepower to the pavement is an FE5 sport suspension that includes a host of other chassis, steering and braking revisions – and a set of gorgeous, 18-inch forged aluminum wheels. The elements pull together to give the vehicle surprisingly agile ride and handling characteristics, as well as an enviable maximum lateral acceleration rate of 0.9 g – making it the best-handling car in the segment.
“There was a concerted effort to tune the Cobalt SS for competitive track performance,” said Heinricy. “This makes the car not only formidable in sanctioned competition, but it puts a finer edge on street performance.”
The MacPherson strut independent front suspension uses SS-specific gas-charged twin-tube struts; unique steering knuckles with optimized geometry; 27 N/mm linear coil springs with specific damper tuning; stiffer control arm handling and stabilizer bar bushings; and a direct-acting, 24-mm solid stabilizer bar. At the rear, the SS’s semi-trailing twist beam axle uses monotube gas-charged shocks with specific damper tuning, a 24-mm solid stabilizer bar, stiffer axle bushings and multi-rate coil springs (28-40 N/mm). StabiliTrak electronic stability control and traction control are standard.
More than cornering capability, the Cobalt SS’s chassis – along with the available limited-slip differential – also is tuned to mitigate conditions often associated with high-performance front-wheel-drive vehicles, such as torque steer and axle hop. The result is a smooth application of the car’s full performance potential, for quicker acceleration, which should lead to faster lap times for experienced drivers.
An improved electric power steering (EPS) system is tuned to match the SS’s handling prowess. The rack-and-pinion gear has a quick 14.8:1 ratio, which is 10-percent quicker than other Cobalt models, and the new EPS provides improved precision and a more viscous feel.
Brembo fixed-caliper brakes
Four-wheel disc brakes with ABS are standard. They consist of large, 12.4-inch-diameter (315 mm) Brembo front vented rotors with premium, high-performance, four-piston fixed calipers in the front and 11.5-inch-diameter (292 mm) rear vented discs with single-piston calipers.
During spirited drives, this gives the Cobalt SS a more precise and consistent braking feel that resists fading, even after repeated occurrences of hard braking, such as the driving experience on a racetrack.
The Brembo calipers are visible behind one of the Cobalt SS’s most distinguishing features: a set of 18- x 7.5-inch forged aluminum wheels. The wheels ride on SS-specific 225/40-series Y-rated summer tires.
The standard anti-lock brakes are connected to the StabiliTrak electronic stability control system to enhance stopping and handling in emergency and performance driving situations.
Maximum performance – on the street or track
The Cobalt SS was developed by GM Performance Division (GMPD), with a team of engineers and designers dedicated to crafting high-performance vehicles. It features powertrain and chassis enhancements that are similar to the new HHR SS, but with larger Brembo brakes, a slightly “taller” final-drive ratio and specific details that emphasize the Cobalt SS’s pure performance ethic. Details such as more aggressive chassis tuning, Continental performance summer tires, standard Brembo front brakes and larger rear vented disc brakes help maximize its competitiveness on the track.
Engineered to offer more than merely a turbocharged rush of power, an all-new FE5 Sport suspension was developed. It includes specific stabilizer bars, spring rates and damper tuning – all designed to complement the high-output turbocharged powertrain and mitigate afflictions such as torque steer. Driver-selectable modes help maximize performance whether on the street or track. The unique “no-lift shift” feature enables the Cobalt SS to achieve the best acceleration time via an algorithm in the engine controller.
Ensuring the car stops as confidently as it accelerates and corners are four-wheel disc brakes with standard ABS. The front brakes are from Brembo and have a performance-oriented fixed-caliper design, which resist fade better than floating caliper designs; the rear discs are vented for better heat dissipation. Along with these high-performance attributes, the Cobalt SS is equipped with a host of standard safety features, including the StabiliTrak electronic stability control system and side-impact air bags.
With its balanced tuning, the Cobalt SS delivers a quick 0-60 time of approximately 5.7 seconds – thanks to the manual transmission’s “no-lift shift” feature – and an impressive maximum lateral grip of 0.9 g. This combination enabled the Cobalt SS to set a new class record when running the famed Nürburgring racing circuit, posting a time of 8:22.85 minutes.
Every driver’s element – from the highly bolstered seats to the A-pillar-mounted boost gauge – is designed to match the performance capability delivered by the 2008 Cobalt SS’s 260-horsepower (194 kW) turbocharged engine and FE5 sport suspension deliver. In short, the cabin delivers maximum functionality and driver satisfaction.
The features that make up the Cobalt SS’s driver-focused interior include:
Sport seats: The Cobalt SS’s seats don’t just look sporty; modified seatback bolsters and “winged” bottom-cushion bolsters provide excellent support during spirited driving. The seat features contemporary, mesh-style impression cloth coverings with suede-like UltraLux inserts in the center section for additional grip. “SS” logos are embroidered on the front seats.
Contrasting interior colors, including Ebony, Victory Red and Light Gray, contribute to the sporty look and are offered in SS-only combinations. Color-matched door panel inserts complete the theme. The rear seat is trimmed to match the front seats and features enhanced bolster styling to also match the front seats.
Shifter: Compared with other Cobalt models equipped with a manual transmission, the SS features a shifter that has shorter throws between gears and a more precise feel.
No-lift shift: An algorithm in the engine’s controller allows upshifts to be performed very quickly without lifting the throttle.
Steering: The Cobalt SS has a quicker-acting, more precise steering system consisting of a modified steering knuckle and a new steering gear (14.8:1 ratio).
160-mph speedometer: A unique instrument panel gauge cluster is standard; it includes a 160-mph readout (255 km/h) illustrated with large, easy-to-view graphics.
A-pillar gauge: In what is now a signature feature of Chevy models with the turbocharged 2.0L Ecotec, the Cobalt SS comes with a standard A-pillar-mounted turbo boost gauge.
Driver Information Center: The standard Driver Information Center located in the gauge cluster allows the driver to display vehicle performance data, such as tire pressure, fuel economy and several SS-specific features, including a “Competitive” mode. The Competitive mode is designed for closed-course performance driving and adjusts chassis controls (including turning off traction control) in controlled driving conditions. A launch control function is part of the Competitive mode and enables consistent acceleration performance.
Additional changes: SS-specific satin nickel trim accents the cabin, enhancing the distinctive and performance-oriented theme of the SS’s driver environment.