Chevrolet looks to be prepping a turbo-powered HHR crossover with an “SS” badge, sourcing the Pontiac Soltice GXP’s turbocharged, direct-injection in-line four, which was rated at 260 hp and 260 lb-ft of torque (in the Solstice, at least). These shots of the HHR SS mule indicate the bowtie brand engineers are attempting to conceal the intercooler (look at the front bumper). Whether or not the turbo powerplant will make it into this HHR body style or a forthcoming, freshened version remains unclear at this point.

Although nearly all powertrains cross multiple platforms in today’s GM, Chevy has a special history with turbocharging. The 1962 Chevrolet Corvair Monza Spyder is generally believed to be the second widely-produced automobile with a turbocharger (the first being the the ‘62 Olds Cutlass Jetfire).

MIAMI -- BMW, Mercedes-Benz and Corvette prototypes are common sights on Germany's famous Nuerburgring racetrack.

But the recent sight of a mildly camouflaged, yet-to-be-announced 2008 HHR SS doing laps raised eyebrows.

"We are looking for a minimum level of performance when we badge these future SS vehicles," said Cheryl Catton, director, car marketing and retail integration, for Chevrolet.

Some SS models have not lived up to that level, she said: "The best ones we have are Cobalt and Impala."

Catton said several issues must be addressed now when future SS models are developed: "How does it look? How does it ride? How does it handle? How does it perform?"

It has to be a credible vehicle, said Catton, interviewed here this month at the South Florida International Auto Show.

Catton points to the success of the 2006 Impala SS, which accounted for 18 percent of the model's production, up from the automaker's projected 10 percent. A percentage comparable to the Impala is unlikely because of the "different offerings you have with the HHR," she said. But the HHR SS gives buyers "one more option to think about when they walk in."

The HHR shares a platform with the Cobalt. The Cobalt SS is equipped with a 173-hp, 2.4-liter four-cylinder engine that produces 163 pounds-feet of torque. Catton did not reveal the engine planned for the HHR SS.

DETROIT - During the nation's largest celebration of automotive heritage, the Woodward Dream Cruise, Chevrolet introduced the newest member of the prestigious SS family: the 2008 HHR SS.

The HHR SS combines all of the style and capability of the popular HHR family with uncompromising performance, including a turbocharged and intercooled engine that produces 260 horsepower (194 kW), unique exterior styling and an SS-specific interior. The vehicle was developed by GM Performance Division (GMPD), with a team of engineers and designers dedicated to crafting nothing but high-performance vehicles.

"With its muscular stance, turbocharged power and track-capable handling, the HHR SS is a worthy addition to SS lineup," said Ed Peper, Chevrolet general manager. "It also reaffirms in a big way Chevy's commitment to the sport compact market."

Standard features include unique exterior appointments, with all-new front and rear fascias, new front grilles, a rear spoiler and 18-inch polished forged aluminum wheels wrapped with Michelin performance all-season tires. Inside, SS-embroidered sport seats - with ultra suede inserts - a new gauge cluster with 140-mph speedometer, an A-pillar boost gauge and a new, driver-oriented steering wheel and shifter support the serious driving capabilities.

Along with its high-performance attributes, the HHR SS comes standard with a host of safety and convenience features, including the StabiliTrak electronic stability control system and four-wheel disc brakes with ABS. Optional equipment includes side-impact air bags and a power-operated sunroof.

"This vehicle delivers all of the style, comfort and convenience found in the HHR portfolio, but also offers outstanding performance and versatility without sacrificing fuel economy," added Peper. "There's simply nothing else like it when it comes to four-door driving fun for the value."

The HHR SS arrives in dealerships in the fourth quarter of 2007.

An SS from the get go

The '08 HHR SS was engineered by GM Performance Division and is the first SS model developed since GMPD was charged with overseeing all of the "go, stop and turn" requirements demanded of any new Chevrolet wearing the SS badge.

"Beginning with HHR SS, all future SS models will have superior power, braking and handling capabilities for maximum credibility with our customers and enthusiasts alike," said John Heinricy, GM Performance Division executive. "The SS badge represents high performance, and the HHR SS delivers with a fully-integrated, balanced driving experience."

To that end, the HHR SS was engineered to offer more than simply increased power. An all-new FE5 Sport suspension was developed and tuned at Germany's famed Nürburgring racing circuit. It includes specific stabilizer bars, spring rates and damper tuning - all designed to complement the turbocharged powertrain.

Consequently, the HHR SS delivers a sports car-like maximum lateral grip of 0.86 g (with manual transmission). The brake system is enhanced, too, with a four-wheel disc system and standard ABS. StabiliTrak electronically controlled stability control system is standard.

The HHR SS's performance rubber meets the road via Michelin Pilot Sport MXM4 P225/45R18 tires mounted on 18-inch polished forged aluminum five-spoke wheels.

SS style


The HHR SS is distinguished on the exterior with several unique features:

— New air dam-style front fascia with fog lamps
— New mesh-style upper and lower grilles
— New rear fascia with outlet for single bright exhaust tip
— Rear spoiler (mounted above rear glass)
— New rocker moldings
— Body-color door handles, mirror caps and rear license plate surround
— SS badges on the front doors and rear liftgate
— Large, five-spoke 18-inch polished forged aluminum wheels and performance tires are standard and are tailored with the specific body enhancements to give the HHR SS a lower, performance-oriented stance.

Likewise, the available exterior colors enhance the sporty nature of the vehicle. They include Victory Red, Black, Light Tarnished Silver Metallic, Mystique Blue Flash Metallic and Sunburst Orange II Metallic.

Like the exterior, the interior is unique to the HHR SS, including SS-embroidered sport seats with ultra suede inserts, a specific gauge cluster, an A-pillar-mounted turbo boost gauge and a new shifter arrangement. Three interior color combinations are available: Ebony, Light Grey and Victory Red.

With the SS moniker on its front doors and liftgate, GM Performance Division (GMPD) engineers made sure the '08 Chevrolet HHR SS lived up to the heritage of those badges. The HHR SS is not the first production SS model developed by GMPD, with such standouts as the TrailBlazer SS and Cobalt SS Supercharged under its belt, but it is certainly the most important since the group is now responsible for the "go, stop and turn" credibility of all future SS models.

The HHR SS is powered by a turbocharged and intercooled 2.0-liter Ecotec DI engine that delivers 260 horsepower (194 kW) and 260 lb.-ft. of torque (353 Nm) with the standard five-speed manual transmission. It is rated at 235 horsepower (175 kW) with the available automatic transmission.

Features such as "no-lift shift" and other driver-selectable performance modes help the HHR SS achieve 0-60 mph performance in 6.3 seconds and cover the quarter-mile in 14.8 seconds at 98.5 mph. The top speed is more than 150 mph, with the manual transmission.

"The HHR SS offers drivers a totally integrated performance driving experience," said John Heinricy, GM Performance Division executive. "It was developed on some of the most challenging tracks in North America and Europe, and has been tuned to deliver confident handling and road manners, while also maintaining overall ride comfort."

As with other GM Performance Division-developed vehicles, the HHR SS was validated on Germany's famed Nürburgring racing circuit, where it set a new lap record of 8:43.52 minutes for its class, besting the previous record of 8:54.38 held by the Opel Zafira OPC.

"It's not often that you see a vehicle like the HHR at Nürburgring - and you certainly don't see one lapping the track as quickly," said Heinricy. "Frankly, the HHR SS is going to surprise a lot of enthusiasts with its improved control and feel on both the street and the track."

2.0L Ecotec DI turbo engine details

The Ecotec 2.0-liter turbo engine 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 Ecotec engine produce more power while maintaining the lower fuel consumption of a small displacement port-injected engine.

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.

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 HHR 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 HHR 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.

Transmissions

Backing the turbocharged engine is a standard GM Powertrain Sweden F35 five-speed manual transmission; the optional automatic is GM Powertrain's 4T45 electronically controlled four-speed. 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 with the manual transmission - 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 enhances confidence behind the wheel, giving the driver a firmer, more direct and quicker shift feel. The manual shifter also is located higher than other HHR models, placing it in a more intuitive position for performance driving. An SS-specific center console is wrapped around the short-throw shifter.

A limited-slip differential is available with the manual transmission.

Chassis tuning and brakes

Conveying the HHR 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 0.86 g (with the manual transmission) - grip comparable to many sports cars on the market.

The MacPherson strut independent front suspension uses SS-specific gas-charged twin-tube struts, unique steering knuckles with optimized geometry, 28 N/mm linear coil springs with specific damper tuning, stiffer control arm handling and stabilizer bar bushings, and a direct-acting, 23-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 (30-40 N/mm). StabiliTrak electronic stability control and traction control are standard.

A unique 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 20 percent quicker than other HHR models, and the new EPS provides improved precision and a more viscous feel. A smaller-diameter steering wheel enhances the quick, sporty steering capability.

Four-wheel disc brakes with ABS are standard. They consist of 11.65-inch-diameter (296 mm) front vented rotors with 54-mm single-piston calipers in the front and 9.84-inch-diameter (270 mm) rear solid discs with 38-mm single-piston calipers. The standard anti-lock brakes are connected to the StabiliTrak electronic stability control system to enhance stopping and handling in emergency driving situations.

The disc brakes are visible behind one of the HHR SS's most distinguishing features: a set of 18-inch polished forged aluminum wheels. The wheels have a Corvette-inspired split-spoke design and ride on SS-specific Michelin Pilot Sport performance tires that are rated for all-season driving.