What’s under the hood?

The new Saab 9-3 SportCombi will debut at Geneva very soon.  It’ll make it’s way to Australian shores some time in 2006, though the US, Canada and other markets will see it sooner.

One of the big stories to come out of the announcement of this model is the fact that it will offer a 2.8L turbocharged V6.  And it’s built here in Australia!!!

From GM Media, here’s the lowdown on the engine….

General Motors expands the family of advanced global V-6 engines with the sophisticated 2.8L V-6 Turbo � a transverse-mounted compact and lightweight powerhouse that delivers the performance of a larger-displacement engine.

The 2.8L V-6 Turbo debuts in the all-new Saab 9-3 SportCombi,

Sedan

and Convertible, continuing the brand�s heritage of turbo power established in 1977. It is the most sophisticated turbocharged engine ever offered in a Saab vehicle, delivering excellent responsiveness through low-speed torque and high-rpm power as well as exceptional refinement.

Technology such as a dual-scroll turbocharger and variable intake valve timing helps the 2.8L V-6 Turbo achieve 250 horsepower (184 kw) and 258 lb.-ft. of torque (350 Nm) in the 9-3.

�The 2.8L V-6 Turbo has a strong, linear feel that gives the impression of a larger-displacement engine,� said Tim Cyrus, global V-6 chief engineer. �The feeling of power is tremendous, but so is the smoothness and refinement built into the engine.�

Developed in conjunction with other engines in the global V-6 family, turbocharging was designed into the architecture�s structural parameters. The powertrain engineers� experience with turbocharging at Saab was integral in refining the engines� performance, with the 2.8L V-6 Turbo delivering maximum torque by 2,000 rpm and maintaining it through 4,500 rpm. Ninety percent of peak torque is available from just 1,500 rpm. This broad performance spectrum results in an engine that effectively offers two torque curves: a linear curve that delivers exceptional low- and mid-range torque, and higher-rpm power that benefits from the pressure of the turbocharger.

�It�s almost like having two engines on tap,� said Cyrus. �At low speeds, the inherent torque of the V-6 pulls strongly, but it has the power of a larger-displacement engine when the full power of the turbo system is called up.�

Inside the engine

All engines in the global V-6 family share traits that include a lightweight aluminum cylinder block with iron cylinder sleeves, an aluminum structural oil pan and aluminum cylinder heads with four valves per cylinder. The 2.8L V-6 Turbo builds on those strengths with components and technology developed specifically for the turbo system, including:

  • Twin-scroll turbocharger delivering approximately 9 pounds of boost (0.6 bar)

  • Integrated charge cooling

  • Unique cylinder heads made from 356T-6 aluminum and featuring sodium-filled exhaust valves

  • Forged steel crankshaft and sinter-forged connecting rods strengthened for turbocharged loads

  • Pistons with anodized ringlands designed for turbocharger boost pressure

  • 9.5:1 compression ratio

  • Piston oil cooling jets

  • Unique camshaft profiles designed for turbocharger performance

  • Hydroformed �dual skin� exhaust manifolds with stainless steel inner liners

  • Engine-mounted oil cooler

The turbo system features a unique, twin-scroll turbocharger. It has an integral bypass valve and is fed by two exhaust ducts � one from each cylinder bank. Separating the exhaust gas pulses with two compressor zones improves gas flow and reduces energy loss. The turbo system�s charge cooler promotes performance by reducing the temperature of inlet air.

Additionally, the 2.8L V-6 Turbo employs a conventional, single-stage intake manifold and variable valve timing on the intake camshaft � the variable valve timing helps optimize performance and emissions control. Also, a variable fuel pressure system helps ensure smooth idle and driving characteristics. Valve timing and fuel pressure are managed by the engine�s powerful controller, a 32-bit micro-hybrid system which is calibrated specifically for the turbocharged application.

The sophisticated controller operates under a torque-based engine management strategy designed to deliver smooth performance in all driving conditions. The system works with the vehicle�s transmission to modulate torque, providing stirring performance and excellent engine response. The system also can limit torque in low-traction conditions, helping provide confident, sure-footed driving. 

Cross-globe connection

The 2.8L V-6 turbo is the third variant of the new global V-6 family � a technologically advanced 60-degree, dual overhead-cam architecture designed to produce strong power and excellent fuel economy to meet different needs in markets around the world. Engineers from GM Powertrain in

North America

and FGP � the Europe-based Fiat-General Motors Powertrain consortium � as well as Holden collaborated on the development.

The global V-6 engine family also includes a 2.8L V-6 VVT normally aspirated version which debuted in the 2005 Cadillac CTS, as well as a 3.6L V-6 VVT version that also is available in the CTS. The 3.6L V-6 VVT also is available in the 2005 Cadillac STS and SRX, as well as the Buick Rendezvous and LaCrosse. It is available under the Alloytec brand name in the 2005 HoldenCommodore,

Calais

, Berlina short-wheelbase, Statesman and Caprice long-wheelbase, Ute, Cab Chassis and Crewman.. Both VVT engines use variable valve timing on the intake and exhaust valves for optimal performance and emissions control.

The 2.8L V-6 Turbo is built at Holden�s Port Melbourne, Australia facility, along with 3.6L variants of the global V-6. 

2.8L V-6 Turbo Specifications

Assembly site:

Port

Melbourne

,

Australia

Applications:

Saab 9-3 SportCombi,

Sedan

and Convertible

Type:

2.8L DOHC turbocharged V-6

Displacement (cu in/ cc):

170 / 2792

Bore x stroke (in x mm):

3.50 x 2.94 / 89 x 74.8

Block material:

aluminum

Cylinder head material:

356T-6 aluminum

Intake manifold:

cast aluminum

Exhaust manifolds:

hydroformed �dual skin� w/ stainless steel liners

Compression ratio:

9.5:1

Valve configuration:

overhead cam; four valves per cylinder

Valve lifters:

hydraulic lash adjuster, roller finger follower

Firing order:

1 – 2 – 3 – 4 – 5 � 6

Fuel system:

sequential fuel injection

Horsepower (hp / kw):

250 / 184 @ 5500 rpm (est)

Torque (lb-ft / Nm):

258 / 350 @ 2000 rpm (est)

Fuel shut off:

6500 rpm

Crankshaft:

forged steel

Connecting rods:

sinter-forged metal

Additional features:

electronic throttle control, variable intake valve timing, variable fuel pressure, pressure-actuated piston cooling jets, extended-life spark plugs, extended-life coolant, GM Oil Life System, oil level sensor, extended-life accessory drive belt

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