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2007 Pontiac Solstice GXP
From its 2002 auto show introduction to an early-order program that sold 1,000 cars in 41 minutes, the Pontiac Solstice has always invoked a passionate response from customers. Now, Pontiac is taking the vehicle’s combination of sensuous styling and driving exhilaration to a new level with the announcement of the turbocharged 2007 Solstice GXP.
Pontiac Debuts the Solstice GXP Performance Car
“Creating a GXP performance edition of the Solstice is a natural extension of the capabilities of this car,” said John Larson, Pontiac general manager. “On its own, the base Solstice offers all of the qualities one would expect from a classic roadster – style, crisp handling, and spirited performance. The Solstice GXP takes that pure roadster DNA and pushes it to a new level, with a 47 percent boost in horsepower and other enhancements for a more thrilling driving experience.”
Advanced Combustion Technology Improves Power and Efficiency in the 2007 Pontiac Solstice GXP
General Motors introduced the Ecotec 2.0-liter Turbo engine in the 2007 Pontiac Solstice GXP, making it GM’s first direct injection offering in North America. Gasoline direct injection technology helps the Ecotec engine produce more power while maintaining the lower fuel consumption of a small displacement port-injected engine. It produces 260 horsepower and 260 lb-ft of torque, making it GM’s highest specific output engine ever, at 2.1 horsepower per cubic inch of displacement (130 hp per liter), and the most powerful production engine in the Ecotec family.
Variable valve timing and an intercooled, twin-scroll turbocharging system are used to optimize the Ecotec 2.0-liter Turbo engine’s performance. It was developed with the global resources of GM Powertrain in the United States and Europe, drawing on expertise from the naturally aspirated Ecotec 2.2-liter direct injection engine used in some European applications and the 2.0-liter turbocharged engines already in production.
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,” said Ed Groff, assistant chief engineer, Ecotec 2.0-liter Turbo engine. “The Ecotec 2.0-liter Turbo produces the power expected of a V-6, but in a smaller, more efficient package – and the driving response is simply terrific.”A dual-scroll turbocharger with a lightweight turbine provides nearly instant power and an air-to-air intercooling system bolsters the turbo’s performance by reducing inlet temperatures. Dual cam phasing complements the turbocharging system by optimizing valve timing at lower rpm for best turbo response and quick engine torque build-up time.
The Ecotec 2.0-liter Turbo uses a stronger, “Gen II” Ecotec engine block, which was developed with input from racing experience to support increased horsepower and torque. The cylinder block bulkheads – the areas where the main bearing caps are attached – and the bore walls are enlarged for strength. Other areas of the engine were enhanced to reinforce the structure and the water jacket is deeper for added cooling capacity and improved cylinder bore roundness. This architecture is shared with the 2.4-liter Ecotec engine that debuted in the Pontiac Solstice roadster.
How Direct Injection Works
Gasoline direct injection differs from the fuel delivery process of a conventional engine by delivering fuel directly into the combustion chamber, where it is mixed with air drawn in to the chamber. The combustion process of conventional fuel injected engines uses air and fuel that are mixed in the intake port or intake manifold prior to being introduced into the combustion chamber. Direct injection is a continuation of the evolutionary process of moving the fuel introduction point closer to the combustion location to improve control.
With the Ecotec 2.0-liter Turbo, fuel is introduced directly to the combustion chamber during the intake stroke. As the piston approaches top-dead center, the mixture is ignited by the spark plug, giving the name spark ignition direct injection (SIDI). The fuel injectors are located beneath the intake ports. SIDI allows the mixture to be “leaner” – less fuel, more air – at full power. SIDI also permits a slightly higher compression ratio than if the fuel were delivered with conventional fuel injection. The result is better fuel consumption at part and full throttle. The engine uses conventional spark plugs similar to other Ecotec engines.
A high-pressure, returnless fuel system is employed. It features a high-strength stainless steel fuel line that feeds a variable-pressure fuel rail. Direct injection requires higher fuel pressure than conventional fuel injected engines and an engine-driven high-pressure fuel pump is used to supply up to 2,250 psi (155 bar) of pressure. The system regulates lower fuel pressure at idle – approximately 752 psi (50 bar) and higher pressure at wide-open throttle. The cam-driven high-pressure pumps works in conjunction with a conventional fuel tank-mounted supply pump.
Direct injection’s precise fuel delivery enables more complete combustion to help reduce emissions, particularly on cold starts – the time when most engine emissions are typically created. Also, direct injection permits higher a compression ratio in the engine which is a positive influence on fuel economy. At certain power levels, the boosted SIDI engine can provide significant fuel economy benefits to the vehicle compared to a larger displacement naturally aspirated engine.
Turbocharging System
A unique, dual-scroll turbocharger is partnered with an air-to-air intercooling system to provide up to approximately 20 psi (1.38 bar) of power-enhancing boost. The dual-scroll turbocharger delivers nearly instant response, as dual exhaust passages from the engine to the turbine housing guide exhaust gas to the turbine. This reduces lag time, or spool-up, at low rpm.
“There is virtually no lag with this system,” said Groff. “Throttle response is immediate. The engine acts like a larger displacement engine.”
The turbocharger is matched to the engine’s displacement and performance objectives. It is supported by the air-to-air intercooling system, which uses fresh air drawn through a heat exchanger to reduce the temperature of the warmer compressed air forced through the intake system by the turbocharger. Inlet temperature is reduced by approximately 212 degrees (100 degrees C), enhancing performance because cooler air is denser and promotes optimal combustion.
The GXP’s high-performance Ecotec turbo engine is connected to a standard five-speed manual gearbox, or an optional five-speed automotive transmission. Either transmission can propel the car from zero-to 60 mph in under 5.5 seconds.
The Solstice GXP is Not Just Another Solstice
As with other members of GXP family, the Solstice GXP provides a number of standard features not available on the base model, including:- Unique front and rear fascias
- High polish, dual-outlet exhaust
- StabiliTrak vehicle stability enhancement system
- 3.73 rear axle ratio
- Interior refinements including unique GXP gauge cluster and Cobalt Red seat stitching
The GXP also comes standard with a number of features available as options on the base model, including:- Sport suspension system
- Four-wheel disc brakes with anti-lock
- Limited-slip rear differential
- Power window/locks/mirrors and remote keyless entry
- Leather-wrapped steering wheel with accessory controls and cruise control
- Driver information center
- 18-inch polished aluminum wheels
- Additional options include a rear deck spoiler, leather seating, sport metallic pedals, chrome wheels, enhanced audio options, including XM Satellite Radio, and OnStar.
The 2007 Solstice GXP will be available in fall 2006
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