Archive for April, 2005
Posted on 27. Apr, 2005 by Ryan.
Photo Credits: Saab Automobile
Saab 9-5, 9-3 Hatchback Rated as â€œSafest Carsâ€ in Swedish Road Accident Study
Detroit, MI â€“ The Saab 9-5 and Saab 9-3 hatchback are rated as the safest cars in Sweden following the latest road accident study conducted by Folksam, the country’s leading insurance company.
The Folksam report, â€œHow Safe is Your Car?â€, updated every two years, features findings based on an assessment of personal injuries suffered in real-life accidents on Swedish roads. In winning Folksam’s safest car award, the Saab 9-5 and 9-3 hatchback were honored for scoring the lowest injury risk rating of 138 different car models in the study.
The findings are based on an analysis of 94,100 car-to-car road accidents in Sweden since 1994 involving injuries to 35,400 occupants. An injury risk measurement is produced for each car model on which there is sufficient data available, including a wide variety of German, Japanese and other Swedish car brands.
Apart from winning Folksam’s overall award, the 1998-2005 Saab 9-5 and 1998-2003 Saab 9-3 hatchback each topped their own respective categories, for large and medium -sized cars. The Saab 9-5 also won Folksamâ€™s safest car award two years ago.
Both models have been developed according to Saab’s â€œReal-Life Safetyâ€ philosophy, which involves computer simulations and crash testing designed to replicate what happens in real collisions on real roads. These are derived from detailed analysis of actual accidents involving Saab cars on Swedish roads. The Saab database now covers more than 6,100 real-world collisions.
“This latest Folksam report is further independent confirmation of the effectiveness of our long-term work with car safety,” emphasized Per Lenhoff, manager of Crash Safety Development at Saab Automobile.
Saab cars are also highly rated in studies and tests carried out in the United States by the Insurance Institute for Highway Safety (IIHS) and the Highway Loss Data Institute (HLDI). Based on top results in separate frontal and side impact crash tests, the 2004 Saab 9â€‘3 Sport Sedan earned a â€œDouble Best Pickâ€ designation from IIHS, the first passenger car to achieve this distinction. In a 2004 HLDI study covering model years 2001-2003, the Saab 9-5 sedan topped the luxury midsize category for relative frequency of injury insurance claims.
As a further affirmation of Saabâ€™s safety achievements, the 2003 Saab 9-3 Sport Sedan, 2004 9-3 Convertible and 2003 Saab 9-5 have each earned five stars, the highest rating possible, in the European New Car Assessment Programâ€™s (EuroNCAP) frontal and side-impact crash tests. EuroNCAP, Europeâ€™s leading crash-test agency, conducts tests on European model variants using three types of collisions: a frontal offset barrier impact and two different kinds of side impacts. The test results are then evaluated according to a large number of parameters relating to driver and passenger safety.
Lenhoff notes that a vehicle’s safety performance is the product of many factors, including driver and occupant behavior, personal judgment and other variables. The design of the car also influences its real-life safety integrity. â€œReal-Life Safetyâ€ means that Saabâ€™s goal is to develop cars that provide safety in real-world crashes
Saab is a division of General Motors Corp. Saab Cars USA is the distributor of Saab 9-2X, 9-3 and 9-5 vehicles for Saab Automobile AB, Sweden. For more information, please visit www.saabusa.com.
Posted on 20. Apr, 2005 by Ryan.
Photo Credit: Saab Automobile
Talking Torque: the secret of Saab’s pulling power
Engine power is usually described as ‘horsepower’ but there is a measure of mechanical output that is often overlooked and also important for everyday driving: torque. But what is the difference between the two? And where does turbocharging fit in? Here Saab, the Swedish turbo pioneer, explains the importance of talking torque.
In 1977 a new instrument appeared on the dashboard of Saab’s top-of-the-line model – a turbo boost gauge. Watching the needle flick round to maximum indicated the onset of fierce acceleration, delivered with a characteristic ‘shove in the back’, never experienced before in a normal production road car. The novel sensation that raised eyebrows was, in fact, the unique ability of turbocharging to raise torque.
Torque and Horsepower are related, but different, measures of what is commonly called ‘power’. Torque provides power for acceleration, whereas maximum horsepower – in combination with effective aerodynamic design – determines a vehicle’s maximum speed.
Torque is best described as the twisting or turning force that is applied to an engine’s crankshaft by the power stroke of the piston when combustion releases energy from the fuel/air mixture. It is an expression of the work the engine is performing, whereas horsepower is a measure of how fast that work is being carried out. Horsepower became adopted as a unit of power because the first mechanical engineers decided, quite naturally, to compare the performance of their new steam engines to the output of a horse.
In an engine, maximum torque is always generated at a slower engine speed than peak horsepower. As engine revolutions increase, there is progressively less time for pressure in the cylinders to be fully developed. This means torque will begin to decrease, although total power output – the engine’s horsepower – will carry on rising with engine speed because there will more, though less powerful, ‘power’ strokes in a given period of time.
More torque is what turbocharging is all about. Put very simply, it is a means of forcing more air into an engine so that it can burn more fuel, release more combustion energy and produce more power.
A turbocharger pumps more air into the engine by harnessing the waste energy in its exhaust gases and, in engineering terms, is an elegant solution because it makes use of energy that is otherwise lost. It essentially comprises two wheels – a turbine and a compressor – mounted on either end of a revolving shaft. The turbine wheel is driven round at extremely high speeds (up to 200,000 rpm) by the exhaust gases from the outlet side of the engine. The compressor wheel spins at the same speed and uses centrifugal force to pack pressurized air into the inlet side.
The principle is known as ‘forced induction’ and a supercharger works in the same way, except that its compressor is mechanically driven directly by the engine, usually off the crankshaft.
Turbocharging boosts engine torque by increasing pressure in the cylinders through allowing stronger combustion, giving that characteristic surge in acceleration. A turbo engine’s total power output – its peak horsepower – will also increase, but it is the enhancement of torque that is most noticeable. Higher torque is also spread across a wider engine speed range than is possible with a naturally-aspirated engine.
Behind the wheel
The driver feels the benefit of turbocharging every time acceleration is required: taking off from rest, overtaking in traffic or when encountering an incline. The full effect is felt at those engine speeds, roughly 2 – 4,000 rpm, which we use in everyday driving.
For strong acceleration, there is no need to keep a turbo engine ‘on the boil’ by maintaining high engine revs through constant gear changing. Without the assistance of such high torque, the driver of a car with a naturally-aspirated engine must keep up the pursuit of maximum brake horsepower*, while the turbo driver can ride the crest of a wave of torque.
Although turocharging can be successfully applied to an engine of any displacement size, Saab originally introduced the technology to give its two-liter engines the performance characteristics of a far bigger powerplant. In effect, it gives the driver the use of ‘two’ engines instead of one. At medium to high throttle openings, a turbocharged unit provides the power of a much bigger engine, while under a light throttle, it will behave much like a smaller, naturally-aspirated engine because the turbo is not, or only partially, engaged. ‘Big’ engine power is available as and when required, without the downside of continuously high fuel consumption.
Turbocharging is part of Saab’s DNA. In taming the technology for road cars, Saab engineers demonstrated a capacity for innovative thinking that continues to drive the brand forward. And in leveraging the power of torque, Saab injects its products with an exhilarating dose of acceleration that is a hallmark of their sporty appeal.
* The expression ‘brake horsepower’ (bhp) refers to horsepower measured at the engine’s crankshaft when it is running on a dynomometer, often called a ‘brake’ as it controls the crankshaft’s speed of rotation.
Posted on 20. Apr, 2005 by Ryan.
Photo Credits: Saab Automobile
Saab’s Technical Heritage: harnessing the power of the turbo
Saab put turbocharging on the automotive map when it pioneered the technology for use in production cars. It is the cornerstone on which Saab has based its powertrain development and remains central to a story of technical innovation and evolution that is still unfolding.
The image of a black, 3-door Saab 99, with its sharp-finned ‘Inca’ alloy wheels and the word ‘turbo’ emblazoned on its flanks and tailgate, has become a long-established motoring icon. Its arrival heralded the dawn of a new era, rewriting conventional wisdom that equated engine power with engine size.
By today’s standards, extracting 145 bhp from a 2.0-liter engine does not sound particularly impressive, but in 1977, when the first turbo model was unveiled, it was regarded as little short of remarkable. Fitting a turbocharger gave 23 per cent more maximum power and a massive 45 per cent increase in torque. To achieve those kind of figures, a naturally-aspirated engine of the time would have been up to 50 per cent larger in capacity and about 50 kg heavier, with overall fuel consumption 30 per cent worse.
Under the impact of higher fuel prices brought about by the first oil crisis of 1973, turbocharging was undoubtedly the right technology at the right time. It gave ‘big’ engine power as and when required, without the downside of continuously high fuel consumption. It is a recipe for enjoyable driving that is just as relevant to the economic climate of today.
While Saab did not invented the turbo – that distinction went to the Swiss engineer Alfred J. BÃ¼chi in 1905 – it was the first to car maker to popularize the technique for road car use. Turbocharging and supercharging had, of course, been seen in aero, motor sport and commercial diesel engines, but until the Saab 99 Turbo arrived, turbocharging for cars had been the preserve of a few exclusive, limited run, special models that were an extremely rare sight on public roads anywhere.
It was turbocharging that added a fresh, sporty dimension to the appeal of Saab cars, opening up major global markets by bringing the brand to the attention of a far wider audience. As an acknowledged master of the art, Saab continues to improve and refine turbocharging technology. Advances in engine management systems have given today’s turbo engines a much smoother and more progressive power delivery. And smaller, but faster spinning, turbochargers now respond to the throttle so quickly that the transition from ‘off ‘ to ‘on-boost’ is virtually seamless.
A new era in Saab powertrain development began with turbocharging. Looking back over almost three decades, a series of milestones can be identified along a path that has led to the launch of the new Saab 9-3 Aero 2.8V6 Turbo, the modern day counterpart of that first 99 Turbo.
A Saab-developed wastegate was used to control the build-up of boost pressure on first Saab 99 Turbo. This was a ‘dump’ valve designed to vent some of the exhaust gas if pressure threatened to exceed a safe maximum level, preventing the possibility of stress damage to the structure of the engine. Nowadays, it is a miniaturized by-pass valve in the turbocharger body.
Automatic Performance Control (APC) is announced to protect the engine from harmful premature ignition or ‘knocking’ that was possible due to the wide variations is fuel quality at the time. An acoustic sensor detects the onset of knocking and turbo boost pressure is immediately reduced whenever necessary. The protection offered by APC also gives engineers greater freedom to raise the turbo engine’s compression ratio
A major step forward in power and performance with the introduction of a 16-valve, double overhead camshaft engine replacing the 8-valve, single camshaft arrangement. Improved engine breathing and more efficient dome-shaped combustion chambers help lift power from 145 to 165 bhp (later to 175/185 bhp in ‘Aero’ models) and torque up from 235 to 273 Nm.
Intercooling increases the intake air density to give more power, and better economy, by allowing more fuel to be burnt more effectively. The hot, pressurized charge immediately downstream of the compressor wheel is cooled by passing it through an air-to-air heat exchanger, or mini-radiator.
Saab Direct Ignition system (SDI) introduced. A sold-state cartridge with computerized control and individual spark plug coils replaces the distributor, contact-breakers and HT plug leads. This eliminates all moving parts, providing more reliable performance and allowing much higher voltages for stronger spark generation. Other refinements include the release of a burst of sparks to burn away moisture on the spark plug electrodes if the engine fails to start first time from cold.
The reliability of the latest turbo engines is demonstrated by three standard production 9000 Turbo models during a high speed, non-stop endurance run at the Talladega Speedway in the United States. Stopping only for fuel, servicing and driver changes over 100,000 kms, the lead car averages 213 kph.
Water-cooled turbochargers are introduced, preventing the risk of internal damage through heat-soak. A water jacket around the turbocharger body avoids the possibility of lubricant becoming hot enough to leave burnt deposits on the bearings of the turbo shaft after the engine is switched off.
A light pressure turbocharged engine (LPT) is launched in the 900 model. Operating at a mild 0.45 bar boost pressure, this 145 bhp engine has good torque from under 2,000 rpm without the sharp turn of speed typical of the full-blown engine. It softer, more progressive throttle response appeals to a broader range of customers. The absence of a boost gauge for the first time signifies how Saab now regards the turbocharger as a ‘normal’ engine component.
A 16-valve, DOHC, 2.3-liter turbocharged engine is added to the Saab 9000 range. Featuring counter-rotating balancer shafts for smooth running, this all-new engine delivers 200 bhp and an impressively elevated, flat torque ‘curve’ with an outstanding 330 Nm from just 2,000 rpm.
Saab introduces is own, in-house engine management system, called Trionic. Integrating the control of ignition timing, fuel injection and turbo boost pressure, Trionic supercedes the SDI system. The Saab-written software is among the world’s most sophisticated, utilizing 32-bit processing power capable of two million calculations per seconds.
Trionic uses the spark plugs as ionization sensors by passing a weak current between their electrodes after each ignition in order to measure the quality of combustion. Adjustments are made for each cylinder individually to optimize running efficiency. Electronic throttle control and the measurement of air mass intake volume are further parameters to be added later.
Saab announces the world’s first asymmetrically-turbocharged engine. The turbo is fitted only to the front cylinder bank of a transversely-installed 3.0-liter V6, but delivers its charge to both. The light-pressure turbocharger is extremely small and integrated in the exhaust manifold for efficient packaging. It delivers 30 per cent more torque, which allows high gearing for reduced fuel consumption together with impressive pulling power.
Saab returns to the Talladega Speedway in the United States to set more endurance production car speed records. Covering distances up to 25,000 miles (more than 40,000 km), the lead 900 Turbo maintains an average speed of 226.450 kph.
A new generation of all-aluminum, four cylinder turbo engines is launched in the Saab 9-3 Sport Sedan. The turbocharger is now fitted inboard, behind the transversely-installed engine, to allow quicker warm-up for the front exhaust catalyst and lower cold start emissions. Trionic 8 engine management adds further engine torque and temperature control.
Saab announces the development of a 2.0-liter BioPower turbo engine capable of running on ethanol (E85), a carbon-neutral, renewable energy source, or gasoline in any combination. The engine management system is programmed to automatically accommodate the different ignition timing and fuel/air mixture requirements of ethanol.
An all-new, aluminum 2.8V6 Turbo engine is launched with a single centrally-mounted turbocharger producing 250 bhp and 350 Nm maximum torque between 2,000 and 4,500 rpm. The twin-scroll turbocharger is fed by two inlet tracts, one from each cylinder bank, to separate the exhaust gas pulses, improving gas flow, reducing energy losses and raising efficiency. The engine breathing benefits of variable valve timing are combined with turbocharging for the first time.
Today, the majority of the world’s car manufacturers include turbocharged gasoline engines in their product line-ups. And the promise of ‘big’ engine performance with smaller engine fuel economy continues to attract successive generations of drivers.
The advent of advanced engine control systems has led to levels of operating efficiency beyond the scope of engineers 30 years ago. But nothing has yet been developed to replace the functionality of a turbocharger and Saab’s development work shows that sophisticated technology is providing the key to unlock its full potential.
Posted on 20. Apr, 2005 by Ryan.
Photo Credits: Saab Automobile
Saab backs ethanol as next-step towards sustainable mobility
As the automobile motors into its second century, it is fast approaching a crossroads where crucial decisions must be made about the future direction of fuel requirements. To initiate the move towards sustainable mobility and to overcome our dependence on fossil fuels,, Saab believes that ethanol is a viable direction in which to move.
Saab Automobile Managing Director Jan-Ake Jonsson believes Sweden is in a position to lead Europe’s switch to the wide-scale production and use of BioEthanol, a renewable energy carrier that has the potential to meet the fuel requirements for sustainable mobility.
The brand is supporting EU and Swedish government initiatives to encourage ethanol consumption by launching its first flexible-fuel vehicle (FFV) on the Swedish market. The Saab 9-5 BioPower runs on BioEthanol-based E85 fuel or pure gasoline in any combination. First customer deliveries begin in June.
“In the near-term, I am convinced that ethanol is a viable solution to our transport needs,” says Jonsson. “It does not require the introduction of expensive new technology, cars can and are already using it, and it can be easily distributed within our existing supply infrastructure.”
BioEthanol-fuelled vehicles are part of three-pronged approach in General Motors’ overall propulsion strategy. In the near-term, improvements to its gasoline and diesel engines and transmissions, as well as the use of renewable fuels â€“ like BioEthanol â€“ provide the first step. Energy efficient hybrid vehicles will be the next step and fuel cells powered by hydrogen – preferable to renewable sources such as BioEthanal – will offer the ultimate environmental answer.
Saab considers there to be two non-negotiable driving forces behind the adoption of a renewable fuel such as BioEthanol: the environmental need to combat the so-called ‘greenhouse’, or climate change, effect and the need to overcome our dependence on oil, a finite resource where the rapid growth of global demand will exceed supply.
Emissions of fossil carbon dioxide (CO2) from road transportation are widely recognized as a major cause of the ‘greenhouse’ effect, which is responsible for climate change and all its associated problems. In Sweden, for example, close to 40 per cent of CO2 emissions are due to transport. And globally, this trend is accelerating as vehiclenumbers continue to grow. The World Business Council for Sustainable Development estimates that in the next 25 years the world’s vehicle population will double, largely due to huge growth in China and developing economies.
Cars running on BioEthanol, which is produced from agricultural crops, sugar cane or bio-mass, are governed by the same law of physics as those using gasoline. That means both emit CO2, as an inevitable consequence of the combustion process. But there is a crucial difference: burning ethanol, in effect, recycles the CO2 because it has already been removed from the atmosphere by photosynthesis during the natural growth process. In contrast, the use of gasoline or diesel injects into the atmosphere additional new quantities of CO2 which have lain fixed underground in oil deposits for millions of years.
A long-standing natural balance in global CO2 levels began to change more than a century ago, with the advent of industrialization built on the use of fossil energy. A UN body, the Inter-governmental Panel on Climate Change (IPCC), estimates that this process is largely responsible for today’s predicament through generating a 35 per cent increase in the global level of atmospheric CO2.
In seeking alternative energy sources, a reduction of such ‘fossil CO2’ is therefore essential. Saab believes the adoption of BioEthanol can play a crucial role. It is already produced commercially from corn in the United States and from sugar cane in Brazil, where General Motors do Brazil markets its unique Chevrolet Astra 2.0i Multipower sedan, which can run on ethanol, gasoline and even compressed natural gas (CNG).
Brazil, as the biggest and most advanced producer of BioEthanol, has already shown the world how to produce large volumes of ethanol, without any subsidies, at a lower cost than the world market price of gasoline. In Sweden, ethanol is currently produced commercially from wheat and at ETEK’s (Etanolteknik AB) R&D pilot plant at Ã–rnskÃ¶ldsvik, an industrial process for producing it from wood and forest residues is being developed for large-scale commercial applications. The Canadian company, IOGEN, with support from Shell, is also developing new production processes for biomass-based ethanol. In a comprehensive 2004 study, the International Energy Agency, an OECD organization, estimates there is enough global resource of biomass for biofuels such as ethanol to meet two thirds of the world’s current energy needs for transport.
To remove fossil CO2 completely from the environmental loop, emissions during the commercial production of ethanol must also be minimized and modern processes are already moving towards a zero emission status. Success in achieving this will depend on the type of biomass raw material and production processes that are used. The ETEK plant isl targeting, from a life cycle perspective, the zero fossil emission production of BioEthanol.
The EU’s latest directive on energy taxation, effective from 1 January last year, calls on member states to apply reduced taxation or a complete exemption for bio-fuels in pure or low blends. It follows a parallel directive requiring member states to introduce measures by the end of this year that will ensure bio-fuels account for at least 2 per cent of total gasoline and diesel consumption in the transport sector, increasing steadily to 5.75 per cent by 2010.
“The generally high environmental awareness within our society, together with the work at ETEK in Ã–rnskÃ¶ldsvik and other Swedish initiatives, place Sweden in a position to lead the European development of BioEthanol as a near and mid-term solution,” adds Jonsson.
Current developments in Sweden include the introduction of city buses running on pure ethanol, tax incentives and free parking for users of flex-fuel cars and the market-driven establishment of more than 160 filling stations selling E85 fuel. The government has also announced that, by 2008, 25 percent of the country’s filling stations will be mandated to offer renewable fuels. And from this year, governmental agencies are required to source at least 50 percent of cars as eco-friendly vehicles.
“The Swedish government and its agencies are to be congratulated in rising to the challenge. At Saab, we too are making a contribution in developing our 9-5 BioPower model for the Swedish market,” says Jonsson. “We will also be providing demonstrator cars for promotional activities in other European markets as a way of stimulating infrastructure development.
“Ethanol provides an effective first step. It is a bridge that can lead us from obsolete fossil fuels towards new, sustainable technologies that are still under development, such as BioHydrogen fuel-cell vehicles.
“We have reached a turning point where action must be taken if we are to avoid a crisis in meeting our future, sustainableenergy needs for transport.”
Posted on 20. Apr, 2005 by Ryan.
Photo Credits: Saab Automobile
Saab 9-5 BioPower: Environmental care with sporty performance
Saab leads the premium segment in offering a model fuelled by ethanol, an eco-friendly renewable energy source. The Saab 9-5 2.0t BioPower is not only kinder to the environment, it also produces more power and performance than its gasoline equivalent. Sales have already begun in Sweden and demonstrator fleets are to be taken to other European markets.
The new Saab 9-5 2.0t BioPower combines the benefits of ‘going green’ with the enjoyment of sporty performance. It also offers a very practical solution to the environmental needs of customers because it can run, without adjustment from the driver, on ethanol-based fuel or gasoline in any proportions.
Ethanol fuel is produced commercially from agricultural crops or forest residues. Unlike gasoline, its consumption does not raise atmospheric levels of carbon dioxide (CO2), the ‘greenhouse’ gas that contributes to global warming. This is because emissions during driving are balanced by the amount of CO2 that is removed from the atmosphere when crops for conversion are grown. It is currently in Sweden blended (85% ethanol/15% gasoline) and sold as E85 fuel.
Running on E85, the Saab 9-5 2.0t BioPower engine delivers 180 bhp and 280 Nm of torque, compared to 150 bhp and 240 Nm when using gasoline, a significant 20 per cent increase in maximum power and 16 per cent more torque. This gives even sportier performance. The zero to 100 kph dash can be accomplished in 8.5 secs and 80-120 kph in fifth gear in 12.6 secs, compared to 9.8 and 14.9 secs when running only on gasoline
Tests in Sweden, where the pump price of E85 is 25 per cent less than gasoline, show that fuel costs in urban and mixed driving are similar, while a useful 15 per cent gain can be expected at cruising speeds on main roads.
The adaptability of Saab’s powerful Trionic engine management system has facilitated re-programming to accommodate the different ignition timing and fuel/air mixture requirements of E85 fuel. Trionic continuously monitors, detects and makes any adjustments necessary for the use of E85 and gasoline in any combination.
E85 has a much higher octane rating (104 RON) than gasoline, which allows the timing of the engine’s ignition to be advanced, producing more power without risk of harmful ‘knocking’. The only hardware modifications necessary are more durable valves and valve seats, and the use of ethanol-compatible materials in the fuel system, including the tank, pump, lines and connectors.
During the development of the BioPower engine, Saab Powertrain engineers liaised with their General Motors colleagues in Brazil where 100 per cent ethanol (E100), produced locally from sugar cane, is the dominant fuel on the market.
“Our engine management system automatically adjusts for the blend of fuel so, if there is no ethanol available, the customer can simply run on gasoline at any time,” says Kjell ac BergstrÃ¶m, President and CEO of Saab Automobile Powertrain AB. “Turbocharged engines are particularly well-suited to exploiting the benefits of ethanol and our work with this engine indicates there is a great deal of development potential for this fuel.”
As a next step in the current program, Saab is also planning to introduce BioPower models in the 9-3 Sport Sedan, SportCombi and Convertible ranges. Meanwhile, customer deliveries of the Saab 9-5 2.0t BioPower, in sedan and wagon formats, begin in Sweden in June at the same price as gasoline-only models.
The EU is committed to cutting greenhouse gas emissions, including the encouragement of a greater use of bio-fuels for road transport, and a fleet of Saab 9-5 BioPower models is to participate in demonstrations in five EU countries: Holland, UK, Ireland, Spain and Sweden, as well as China and Brazil.
This initiative, BEST (BioEthanol for Sustainable Transport), begins later this year and involves Saab, Scania and Ford Europe, backed by ethanol producers and university research centers. Public authorities and large company fleet operators will have the opportunity to test and evaluate the on-road performance of bio-ethanol powered vehicles.
An EU directive on energy taxation currently requires member states to apply reduced taxation, or a complete exemption, for bio-fuels in pure or low blends. The process is already underway in Sweden. In addition to benefiting from E85 fuel that is 25 per cent cheaper than gasoline, Saab 9-5 BioPower customers are also exempted from city congestion and parking charges, as well as qualifying for a 20 per cent reduction in benefit tax if they are company car drivers.
Saab 9-5 2.0t BioPower: Technical Specifications
1,985 cc. Four cylinders in-line. Bore 90 mm, Stroke 78 mm
Cast iron block, alloy cylinder head.
DOHC chain-driven, 16-valves. Twin balancer shafts.
Compression ratio, 9.3:1
Saab Trionic 7 engine management.
Direct ignition, multi-point fuel injection, electronic throttle control
Posted on 20. Apr, 2005 by Ryan.
Photo Credits: Saab Automobile
Six Cylinder Turbo Power gives Saab 9-3 Aero Class-leading Appeal
Â· Unique offer in segment, more torque than other six cylinder gasoline engines
Â· Saab 9-3 Aero 2.8V6 Turbo fastest-ever Saab
Â· First gasoline V6 designed from start for Saab’s turbocharged application
Â· Light, compact, all-aluminum construction
Â· Twin-scroll turbocharger for smooth response
Â· Variable cam phasing for improved breathing
Â· Stainless steel exhaust manifolds for lower cold-start emissions
Â· Sinter-forged connecting rods for extra strength
Â· Tuned twin exhaust for sporty engine note
The Saab 9-3 Sport Sedan Aero with its new 2.8V6 Turbo engine is, quite simply, the fastest accelerating car ever to carry the Saab badge. It represents the culmination of almost 30 years’ experience from Saab as acknowledged leaders in the art of turbocharging.
For the first time, Saab customers will be able to enjoy the combined benefits of turbocharged power and six cylinder refinement in a purpose-built package. With massive pulling power (350 Nm) spread widely across the engine’s speed range, the 250 bhp/184 kW 2.8V6 Turbo generates more torque than any other six cylinder gasoline engine in the Saab 9-3 segment.
Saab Automobile Powertrain’s expert knowledge and experience of turbocharging is recognized by its role as a Center of Expertise within General Motors for the development of turbocharged gasoline engines. The Swedish engineers were therefore closely involved during the conceptual design and development of GM’s new global V6 engine architecture, ensuring it included the possibility of a turbocharged application.
The 2.8V6 Turbo has a 60Âº vee-angle between its cylinder banks for perfect balance and combines excellent multi-valve refinement with outstanding performance. The all aluminum construction provides a light and compact architecture, well suited to its transverse, front-wheel-drive installation in the Saab 9-3 Aero.
The cylinder heads, each with double chain-driven overhead camshafts operating four valves per cylinder, are of high specification aluminum and unique to this turbocharged variant. The design ensures enhanced heat resistance under 85 bar cylinder pressures, as well as minimum maintenance costs.
Also unique are pistons with hard anodized ring grooves for durability and under-skirt oil jet cooling, together with steel con-rods that are strengthened by sinter-forging, a process that involves molding metal in a powered form. The exhaust valves are filled with sodium to further enhance cooling. The cylinders have cast iron liners and a bore/stoke of 89.00 / 74.8 mm.
For improved engine breathing, variable cam phasing on the inlet side is electronically controlled and hydraulically actuated, allowing continuously variable adjustment through 50Âº of crankshaft rotation. On the road, this translates to a more flexible power delivery and better fuel economy under different engine loads.
A die-cast aluminum oil sump is designed to increase structural stiffness and the strong, four-bearing crankshaft is made from micro-alloy forged steel, a specification more commonly seen in competition performance or diesel engines.
The twin-scroll, water-cooled Mitsubishi TDO4-15TK turbocharger, operates at 0.6 bar maximum boost with intercooling and an integral by-pass valve. It is mounted centrally above the transmission and fed by both banks of cylinders. The use of two separate inlet tracts, one for each cylinder bank, separates the exhaust gas pulses, improving gas flow, reducing energy losses and raising turbocharger efficiency. The turbine wheel is made from a special high-grade steel alloy, commonly used in the turbocharged engines of world championship rally cars, which is resistant to erosion, cracking and creeping under high temperatures and centrifugal forces.
Also unique are double-skin exhaust manifolds, which are hydroformed with stainless steel liners to improve cold start emissions by minimizing heat absorption to the manifold. Air injection into each manifold for up to 30 seconds after a cold start also helps the central pre-catalyst, positioned upstream of the main catalytic converter, achieve ‘light off’, its effective working temperature, as early as possible.
Smart engine management
The 32-bit engine management system, with software calibrated specifically for the Saab 9-3 application, utilizes a torque-based engine control strategy and direct coil-over-plug ignition with a robust engine-mounted control unit. Ignition timing, fuel injection, turbo boost pressure, air mass measurement and the throttle setting are all key engine functions controlled by the software.
The sophisticated control strategy is designed to deliver smooth performance in all driving conditions. The system works with the vehicleâ€™s transmission to modulate torque, providing stirring performance and excellent engine response. The system can also limit torque in low-traction conditions, helping provide confident, sure-footed driving. Variable fuel pressure further contributes to smooth idle and driving characteristics.
For driving comfort, control of the electronic throttle through the movement of the accelerator pedal is programmed to be sensitive to different driving conditions, with greater pedal movement introduced at lower vehicle speeds, such as when maneuvering or parking. At low engine speeds, the engine control system also brings the turbo in quickly by momentarily opening the throttle slightly more than requested by the driver.
On the road the new 9-3 Aero 2.8V6 Turbo packs a formidable punch and the driver will also immediately appreciate the smooth power delivery, like an iron first in a velvet glove. Apart from the boost gauge in the dashboard, the only clue to the presence of a turbocharger is an uncannily effortless rate of acceleration.
Pick-up from tick-over at just 720 rpm is instant, due to the engine’s relatively large multi-cylinder capacity. At about 1,000 rpm, the turbo begins to build a massive wall of torque that is already in place by the time the tachometer swings through 2,000 rpm. It endows the 9-3 Aero with a level of performance never before seen in a Saab car.
Maximum torque is generated all the way from 2,000 rpm to 4,500 rpm, with 90 per cent of this value available at an exceptionally low 1,500 rpm. Careful programming of the engine management software means that under a full throttle load, from take-off or low engine speeds, 90 per cent of maximum acceleration is delivered within one second.
The zero to 100 kph dash is accomplished in just 6.9 seconds, but in-gear acceleration provides even more impressive evidence of this engine’s outstanding elasticity. In top gear, the transition from 80 to 120 kph can be accomplished in just 8.3 seconds, a figure that places the 9-3 Aero among the very best in its class.
The fun-to-drive nature of this performance is also matched by an exhilarating engine note that can be heard inside and outside the car. This has been achieved by tuning the twin sports exhausts downstream of the main catalyst. It gives the new Saab 9-3 Aero a distinctive aural character in keeping with its position as the sporting flagship of the range.
The engine is offered with a choice of six-speed manual or automatic transmissions. The close-ratio manual gearbox includes duel output shafts to reduce transmission vibration, together with a dual mass flywheel this ensures smooth and refined performance.
The ‘smart’ Asin AW automatic transmission is adaptive to driver usage patterns and prevailing road conditions. It can sense changes in engine performance, engine load, road gradient and altitude, quickly finding the right gear without an irritating ‘hunting’.
For closer driver involvement, Saab Sentronic, a sequential manual gearshift, is also included. When the shift lever is moved across the gate to â€˜manualâ€™ Sentronic mode, â€˜upâ€™ and â€˜downâ€™ changes can be made with full lock-up in 3/4/5 or 6th gears. This process is taken a step further by the option of steering wheel buttons, which bring gear-shifting right to the fingertips of the driver.
Overall, the 2.8V6 Turbo generates class-leading levels of torque with a seamless, turbine-like power delivery. It combines the inherent advantages of a six-cylinder engine – refinement and a rapid throttle response – with the effortless, torque-boosting properties of turbocharging.
Saab 9-3 Sport Sedan Aero 2.8V6T:
Technical Specifications and Performance
2,792 cc. V6. Bore 89mm, Stroke 74.8mm
Aluminum cylinder heads and block.
2 x DOHC chain-driven, 24 valves. Variable valve timing (inlet)
Max boost pressure, 0.6 bar
Compression ratio, 9.5:1
Bosch Motronic engine management.
Direct ignition, multi-point fuel injection, electronic throttle control
Max.power: 250 bhp (184 kW) @ 5,500 rpm
Max torque: 350 Nm @ 2,000 – 4,500 rpm
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