Saab today unveiled the 2008 9-3 Convertible, a model that confirms Saab’s leading position in the premium convertible segment and is the product of more than 20 years’ experience in designing four-seater, four season soft tops that are as practical as they are stylish.
The Saab Convertible has a level of structural integrity, build quality and running refinement that places it at the very top of its class. Innovative product features further develop the Saab concept that an open-top car should be ‘more than a Convertible’ by offering effective all-year-round transport. In addition to its functional qualities, the Convertible also offers strong driving appeal through sharing the excellent chassis dynamics of the 9-3 range.
The 9-3 Convertible was developed in tandem with Sport Sedan, ensuring all the special structural requirements for an open top car could be accommodated from the outset of design work. Structural integrity and build quality positions it at the very top of its class.
The 2008 9-3 is powered by a ’tri-fuel’ choice of gasoline, diesel or bioethanol (E85). It is led by an all-aluminum 2.8-liter V6 turbocharged engine rated at 255 hp (188 kW); a powerful two-stage turbo diesel packing 400 Nm of torque and a choice of two Saab BioPower (E85) flex-fuel engines. There is also a 2.0-liter four cylinder turbo gasoline engine.
The 9-3 Convertible features the same sporty handling characteristics as the Sport Sedan. The rigid body structure provides a solid foundation for suspension systems with impressively low levels of noise, vibration and harshness.
Saab products consistently show well in real-life safety surveys, and the 9-3 Convertible joins 9-3 Sport Sedan in achieving a maximum five star EuroNCAP crash safety rating test study. The 9-3 Convertible meets the same crash performance targets as the sedan.
The 2008 the Saab 9-3 Convertible has an impressive look that Convertible radiate power, sporty performance and great strength; all elegantly packaged with a Scandinavian design flair that ensures the lines are clean and flowing, but never cold or clinical.
Saab has unveiled its first open top car as a design study in 1983. Since then, the company managed to demonstrate that a car built for the pleasures of open air driving can also accommodate four adults as a practical, all year round means of transport.
9-3’s deep and prominent grille adopts a theme first seen on the Aero X concept car. This is complemented by sweeping headlamp units that incorporate a thin ‘eyebrow’ lighting zone designed as a brand specific ‘signature’ feature. These units culminate in an upswept rear edge, introducing a Saab design theme from the 9-5 range and classic 900 model. The grille’s central wing motif is retained as a reference to Saab’s aircraft heritage.
The frontal styling sees the adoption of another Saab signature feature: a ‘clamshell’ hood, closing across the top of the front wings. The hood pressing incorporates a sweeping, U-shaped styling line, as first seen on the Aero X, which echoes the curvature of the windshield.
The swept-back frontal lines are complemented by a front bumper and splitter assembly with a deep, trapezoidal air intake, even more pronounced on Aero versions. This is flanked by deep black vents which are framed, like the grille, in a matte chrome finish. As with the Aero X concept, these represent a metaphor for the intakes of a jet engine.
In profile, the clean wedge line is typically Saab and, top down, the shape is no longer interrupted by a tower to mount the front seat-belts. The styling of the rear deck is particularly neat because the pop-up roll bars and retractable rear head restraints are beautifully streamlined by twin fairings, giving a subtle hint of the Convertible’s sporty character. The color-keyed tonneau cover is, of course, flush fitting.
A new design feature, never seen before in Convertible styling, is the introduction of a distinctive Surround Trim, marking the transition zone between the car’s exterior and interior. It is a U-shaped line that extends rearwards from the base of each A-pillar, incorporating slim panels along the top of the doors and rear side trims and most of the tonneau cover.
Real World Aerodynamics
In the field of aerodynamics, the performance of Saab products is optimized for real world conditions, in the same way as Saab has developed its ‘real life‘ safety strategy.
The Convertible’s roof-up drag coefficient is a class competitive 0.34 but, probably more important, major strides have been made in improving high speed stability by keeping rear lift forces low and consistent.
A smooth airflow over, around, through and under the car is important, with particular attention paid to points of flow separation at the rear in order to reduce the size of wake turbulence and improve stability. Here the focus was on the shaping of corner radii and the curvatures at the rear of the roof and the sides of the car..
The behavior of the Convertible’s roof, particularly its effectiveness in resisting ‘ballooning’ at speed and in its seating on the side windows was closely studied. As there is no monoside upper door closure for a Convertible, the effect of the windows being ‘sucked’ outwards, by the difference in outside and inside air pressure, with undesirable consequences for wind noise, had to be addressed. It is actually the same effect that causes ’ballooning’ or flapping.
The overall interior design reflects the curves and flowing lines of the exterior. In the same way, the fascia layout, the supportive seating, the shape of the door panels and trim, together with the feel of the tactile, soft-touch controls, are all very modern interpretations of classic Saab styling themes. It is a warm, harmonious interior, without undue ostentation, that is typically Scandinavian and could only come from Saab.
The high quality materials include the use of Hydroblox, the first water repellent seat upholstery to be fitted to a convertible. A polyester membrane lines the underside of the textile seat covering in order to prevent water penetration. This is a particularly useful feature for a convertible if the driver is caught in a shower of rain, for example, before being able to raise the soft-top.
Attention to detail, so typical of Saab, is everywhere to be seen, no more so than in the rear passenger compartment. In design terms, this relatively small part of the interior of convertibles has become somewhat neglected. As it is generally used only occasionally, and there are no carry-over panels, the standard of finishing trim and upholstery often lacks cohesion, failing to match the quality up front. However, rear seat passengers in this Convertible do not travel second class because Saab’s design team has paid close attention to this ‘forgotten’ area.
Both seating positions are well shaped and upholstered, with deep squabs far superior to the flat, narrow bench seats that are often seen. The rear seat cushion also extends outwards at each end, in a gentle concave arc, right up to the side panels. This complements the shape of the rear cabin and even the tonneau cover. The angle of back-rest is kept at a comfortable 21° from vertical and is not compromised by packaging requirements.
The integration of the front and rear areas is, of course, further reinforced by the unique Surround Trim styling line, described in the exterior design.
The new 9-3 Convertible benefits from one of the most powerful electronics systems to be installed in a series production car (see Body and Systems section for full details).
Fiber optics are used to provide a high-speed platform for the car’s extensive ‘infotainment’ (communication, information and entertainment) functions, a development of cutting edge technology first seen on the Sport Sedan. It is utilized by all three audio system options and, where fitted, the Bluetooth Phone Integration System (BPIS), which features voice control, the GPS navigation system with DVD reader and the OnStar telematics service (US market only).
This network is capable of handling all likely future requirements in the fast-developing field of ’infotainment’ and e-services, making it easy for owners to fit upgrades.
A choice of three ’infotainment’ systems is offered, each of which includes a CD player compatible with MP3 music discs. Also fitted as standard is an auxiliary audio input. The acoustic requirements of a convertible have been carefully examined. For example, the range of volume adjustments for the automatic, speed-sensing control has been increased, including the programming of a slightly wider base response. The BPIS microphone is also installed in the driver’s side A-pillar for convenient use in open top conditions.
The standard ’Saab Infotainment’ system includes an RDS radio and single-slot CD player, ’Saab Infotainment CD Changer’ adds an in-dash 6-disc facility and ’Saab Infotainment Plus’ includes a satellite navigation with a large, 6.5 inch color touch-screen and voice control. In addition to a ’bird’s eye view’ map selection, direction arrows are now shown on the touch-screen.
All three ’infotainment’ systems can be combined with a hands-free mobile phone facility, the Bluetooth Phone Integration System (BPIS). After an initial ’pairing’ set-up procedure, a Bluetooth-enabled phone will automatically connect wirelessly to the audio system whenever the user enters the car. The phone is then operated by voice control or steering wheel buttons, with call information shown in the main instrument display. For recharging and connection to the car’s external antenna, a phone dock in the center console is available as an accessory.
The body structure of the 9-3 Convertible is essentially an open ‘uni-body’ fabricated from steel beams and pressings with all external parts galvanized. Structural engineers used CAD techniques and finite element data models with a resolution of up to 500,000 cells to represent the car’s structure.
About 50 per cent of its 383 structural body parts are unique to the Convertible, and 60 per cent of its body weight is composed of high or ultra high strength steel. However, a more important consideration is how all the elements interact in sharing the load-bearing task. The strength of a good design is far more than simply the sum of its parts.
When work began on the latest Saab 9-3 product range, designers and engineers were for the first time able to ensure that the needs of a Convertible variant were given the same priority as those of a sedan.
In particular, they took up the challenge of engineering an open top car that concedes little or nothing to the structural losses implicit in foregoing a fixed roof. The result is a convertible that shares the Sport Sedan’s much improved, ‘fun to drive’ handling; its solid, vibration-free running refinement and, of course, its impressive crashworthiness. A strong body, stiff in torsion, was an absolute pre-requisite.
The 9-3 Convertible’s body structure is exceptionally stiff and among the strongest in its class, with a torsional rigidity of 11,500 Nm/degree of deflection. It is high torsional rigidity that helps give that reassuring ‘hewn for solid’ feel, which is communicated every time a door is closed or the car negotiates a poor road surface. And it makes a major contribution to eliminating squeaks and rattles, vibrations and resonances.
Chassis engineers also demand a stiff body because the car’s handling can only be effectively honed through the control of its suspension, wheel and steering movements if the structure, on which these components exert loadings, is solid and predictable.
Finally, the car’s ability to withstand a heavy impact is largely due to the strength of its passenger compartment and the ability of the structure’s crumple zones to prevent energy reaching it. ‘Twin’ chassis architecture
To achieve their goals for the Convertible, engineers have successfully installed what is, in effect, a second or ‘parallel’ structure within the car’s platform: an additional, completely linked ‘ring of steel’, extending from the front to the rear of the car.
The most important element of this new structure is a large closed casing, known as the ‘torsion box’, located between the rear wheel housings, immediately behind the rear seat and ahead of the soft-top stowage compartment. It helps compensate for the loss of rigidity as the ‘C’-pillars are no longer connected by the beams of a fixed roof.
The bottom of the torsion box is welded to another completely new large pressing, a combined rear seat beam and floor which also forms the boot well. This is another important link in the structure and, like the torsion box, is welded at each side to the first of two rear inner side panels which, in turn, connect with the lower B-pillar and side sills.
Enlarged side sills, unique to the Convertible, are further major components of this ‘second chassis’. They are 32 mm higher and 8 mm wider, with a 25 per cent larger cross-section, than those of the sedan. They are made even stronger by the addition of an internal longitudinal plate running the whole length of the box section. The three cross bracings are also good for impact resistance.
Forward of the side sills is another crucial area, connecting the sill, the base of the A-pillar, the bottom of the front bulkhead, the sub-frame mountings and the floor. This is heavily reinforced through a structure of four carefully shaped steel pressings.
The upper A-pillars, together with the windshield header rail, provide rollover protection as well as structural strength and are made from no less than four longitudinal steel members with short, strategic cross bracings. The header rail is also reinforced, consisting of three layers of steel. The whole combined structure can withstand a loading of 2.2 times the weight of the car, about 3.5 tonnes.
As the final pieces of the ‘second chassis’ jigsaw, both the front and rear sub-frames are now bolted directly to the body with steel collars, for extra stiffness, instead of polymer bushes. At the rear, two diagonal ‘V-rods’ are also bolted in position as bracings, linking the sub-frame on each side to the mounting of the trailing arm in the rear suspension.
A novel ‘off-set’ spot-welding technique has been developed which can bridge a gap of 40 mm, eliminating any potential weak links or connections where more than two thicknesses of steel are welded together.
The fine chassis dynamics of the Saab 9-3 Convertible are complemented by the outstanding drivability and refinement of an all turbo powertrain line-up that includes engines fuelled by gasoline, diesel and bioethanol (E85). Saab becomes the first manufacturer to offer a premium-class convertible able to run on eco-friendly, E85 fuel.
2.8-liter V6 Turbo
This sophisticated 255 hp (188 kW) engine is exclusive to the top-of-the-line Aero model. Maximum torque of 350 Nm is generated from just 1,800 rpm all the way to 5,000 rpm, with 90 per cent of this value available from an exceptionally low 1,500 rpm.
With a 60º vee-angle between its cylinder banks for perfect balance, the engine 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.
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 application. 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 50º 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. Together with a dual-mass flywheel, these elements further reduce unwanted noise and vibration, ensuring smooth and refined performance.
Choice of Two Diesel Engines
The new 9-3 range features the introduction of a powerful new four cylinder diesel engine with a unique two-stage turbocharging system, a world ‘first’ in the premium segment, giving class-leading levels of efficiency.
The 1.9-liter, 16-valve engine, badged TTiD, produces 180 hp/ 132 kW and 400 Nm of maximum torque, specific power outputs that are unmatched among competitor products on the market. In-gear performance is on a par with the 2.8V6 turbo gasoline engine
The two-stage turbocharger housing is integrated with the exhaust manifold and contains two turbochargers of different sizes. The pair of turbine/compressor wheels are sequentially mounted and each is able to by-pass the input and output feeds of the other, while also being able to operate in tandem
This arrangement provides a driver with ‘the best of both worlds’: good, instant torque at low engine speeds - via the low-inertia small turbo when the exhaust pressure is light - and strong ‘top end’ power at higher revolutions, when the bigger turbo is engaged.
Saab’s two-stage turbocharging uses a system of by-pass valves that directs the exhaust gas stream between the two turbine wheels and also separates the air intake charge from the compressors. From tick-over to 1,500 rpm the exhaust feeds only the small turbo. Between 1,500 and 3,000 rpm the flow is split between both turbines, giving stronger boost and ensuring a smooth transition phase to full power operation, above 3,000 rpm, when only the larger turbo is engaged.
The compact design provides more efficient packaging than systems using two separate turbochargers linked together externally in series. It ensures that the complex control and regulation of gas flows on both the exhaust turbine and intake compressor sides is achieved with a minimal number of seals and connections.
The TTiD engine is a substantial development of the current 16-valve 1.9TiD unit, using common rail, direct and multiple fuel injection. It operates with a maximum boost pressure of 1.8 bar (1.4 bar for the current engine) together with a slightly lower compression ratio of 16.5: 1 (17.5:1). The cast-iron block, alloy cylinder head and all internal components are strengthened as necessary to withstand the higher thermal pressures.
Unique Saab BioPower Choice
Saab leads the premium segment in offering ’flex-fuel’ BioPower engines, which can run on gasoline and/or bioethanol (E85), a renewable fuel with a reduced CO2 impact. As well as being kinder to the environment, Saab BioPower is also the only flex-fuel technology that uses turbocharging to deliver increased power and performance.
In combining the benefits of ’going green’ with the enjoyment of even sportier performance, the development of BioPower reflects Saab’s brand values. It also offers a very practical solution to the environmental needs of customers because a BioPower engine can run on gasoline, without adjustment from the driver, in any proportion if E85 fuel (85% bioethanol/15% gasoline) is not available. With BioPower there is no loss of luggage space or additional weight because the same standard tank is used for both fuels.
The Saab 9-3 Convertible now features the introduction of a 2.0t BioPower engine, in addition to the current version. Running on E85, the 2.0t BioPower engine delivers 14% more maximum power (200 hp/ 147 kW.v 175 hp/ 129 kW) and 13% more torque (300 v 265 Nm). This gives projected zero to 100 kph acceleration in 8.2 sec and 80 to 120 kph in fifth gear in 11.2 sec, compared to 9.0 sec and 12.5 sec, respectively, on gasoline.
On E85, the current BioPower engine delivers 17% more maximum power (175 hp/129 kW v 150 hp/111 kW) and 10% more torque (265 v 240 Nm) than on gasoline. In the 9-3 Convertible, that translates to projected zero to 100 kph acceleration in 8.9sec and 80 to 120 kph in fifth gear in 15.9 sec, compared to 10.5 sec and 17.5 sec, respectively, on gasoline.
E85 has a higher octane rating (104 RON) than gasoline (95 RON), and turbocharging with Saab BioPower allows the use of a higher boost pressure and more advanced ignition timing than is possible with gasoline. This gives more engine power, without risk of harmful ’knocking’ or pre-detonation.
The fine chassis dynamics of the Saab 9-3 Convertible deliver the kind of on-the- road performance that is promised by its sporty looks and purposeful stance. Of course, that is hardly surprising since it shares the core chassis and suspension components of the widely-acclaimed 9-3 Sport Sedan and SportCombi.
The Convertible’s impressive chassis composure, handling agility and ride refinement place it among the very best on the market.
Like the sedan, the Convertible is the product of a rigorous development program, designed to combine the benefits of front wheel drive - predictability and excellent driver feedback - with new levels of chassis control for a more rewarding driving experience.
A rigid body structure and optimized suspension are the foundations on which the Convertible’s chassis poise, refinement and impressively low levels of noise, vibration and harshness have been developed..
Today’s premium convertible customers are prepared to make few, if any, concessions to the absence of a fixed roof. Inherent losses in body rigidity must, therefore, be largely recovered by careful design, particularly around suspension mounting points, to prevent the chassis’s handling and ride composure being compromised.
The work of the chassis engineers was made easier by the Convertible’s separate, but parallel, development program alongside the Sport Sedan.. They benefited from the strategic decisions made by structural engineers to ensure that the architecture and ‘hard points’ for the 9-3 product range could be properly adapted to meet the needs of an open-top car. (A full description of this work can be found in the Body Structure section).
Compared to the 9-3 Sport Sedan, the weight distribution of the Convertible is slightly more favourable, in part due to the addition of the soft-top and its operating mechanism. The front/rear ratio of 55/45 compares well against the 60/40 split of the sedan and helps to offset a 10 per cent increase in kerb weight.
To deliver the high standard of ride quality expected in this class of car, engineers have also sought to minimize unsprung weight. As a result, all four wheel carriers (hubs) and brake calipers, the lower control arms in the front suspension and the toe and lower links in the rear suspension are made of aluminium.
In order to maintain a consistent suspension geometry - as well as helping to raise the chassis’s torsional rigidity – bracing rods are bolted to the rear sub-frame. These ‘V-rods’ run diagonally forward, from near the inboard mounting point for each lower suspension link, into the attachment point for the trailing toe link, reinforcing the sub-frame’s fixing to the body.
And to further eliminate the possibility of any slight movement, four metal sleeves, instead of polymer bushes, are used at both the front and rear sub-frame mounting points.
With these measures in place, the chassis team concentrated on tuning the Convertible’s spring and damper rates, in order to maintain the sporty handling characteristics of the sedan.
The front MacPherson struts keep their de-coupled top mountings, separating the damper and spring loadings, and the aluminium lower control arms are attached, as before, to a hydroformed (hollow section) front sub-frame, including hydraulic bushes on the rearmost mounting each side for optimum damping. There is a single, direct -acting anti-roll bar and, for good directional stability and ride comfort, the suspension layout is designed to be largely impervious to lateral forces and compliant longitudinally.
Saab ‘ReAxs’ – passive rear wheel steer
Out on the open road, the Convertible’s sporty handling characteristics are rewarding and ‘involving’ for the driver due to a unique, passive rear wheel steer characteristic, known as Saab ReAxs, first seen on the Sport Sedan.
The toe-links in the rear suspension and the use of ball joints, instead of rubber inboard and outboard suspension bushings, allow a much closer control of wheel movement. As a result, under cornering loads, the elasto-kinematics at the rear axle induce a very slight deflection of both rear wheels in the opposite direction to the steering input, ie. toe-out for the outer wheel and toe-in for the inner wheel.
Depending on vehicle speed and the radius of a bend, which will vary the consequent loadings at the rear axle, one degree of steering movement at the front wheels would typically produce a small but significant deflection of about one hundredth of a degree at the rear. This is sufficient to prevent excessive understeer, where the driver is forced to apply progressively more steering lock to turn the front end of the car, increasing the scrub angles of the front tyres.
The Saab ReAxs characteristic overcomes this ‘crabbing ‘ effect, helping the tail of the car follow the direction of its front wheels, instead of its nose. For the driver, this makes the car better balanced and more fun to drive, helping it turn in and respond more closely to steering inputs.
The performance of the powerful steel disc brakes is among best in class, giving a consistent pedal feel and showing particularly good resistance to fade under repeated heavy applications.
In EU specification, three brake sizes are fitted according to engine power. For all four cylinder engines, except the 210hp and 200 hp BioPower versions, 285 mm front (ventilated) and 278 mm solid rear discs are fitted. For the 210 hp and 200 hp BioPower engines, they are 302/292 mm (both ventilated) and for the Aero 2.8V6 turbo and TTiD engines these are increased to 314/292 mm.
High speed braking stability is particularly impressive, largely due to the Saab ReAxs control of the rear suspension geometry. This effectively ‘preloads’ the rear tyres by applying some lateral force through toe-in as braking commences.
An automatic brake boost feature, Mechanical Brake Assist (MBA) increases braking pressure from the master cylinder when the driver stamps hard on the brake pedal. This stops the vehicle quicker and also activates the car’s ABS more effectively.
A four channel ABS (Anti-lock Braking System) and a Traction Control System (TCS), with additional electronic throttle control, are both standard fitment. The other standard electronic brake control functions utilise the ABS wheel speed sensors and the variable valving at each wheel.
2008 Saab 9-3 Convertible Specifications
2792cc. V6. Gasoline. Aluminum cylinder heads and block. Twin-scroll turbocharger, intercooled. DOHC, 24-valve. Variable valve timing (inlet). Dual-mass flywheel.
1998 cc. 4 cylinders in-line. Gasoline
Aluminum cylinder head and block. Turbocharger, intercooled. DOHC, 16-valve. Trionic 8 engine management
All engines front, transversely-mounted, Hydraulically-damped. Front wheel drive.
Diesel:1910 cc. 4 cylinders in-line. Aluminum cylinder head, cast iron block. DOHC 16v.
Common rail, direct and multiple injection.
Turbocharged VNT/ 2-stage turbo, intercooled, intercooled. Dual-mass flywheel.
Maintenance-free particulate filter.
1998 cc. 4 cylinders in-line. Aluminum cylinder head and block. Turbocharger, intercooled. DOHC, 16-valve. Balancer shafts. Saab Trionic 8 engine management. Fuelled by bioethanol (E85)/gasoline in any proportions
5/6 speed manual gearboxes.
5/6/5+2 speed automatic transmissions
with Saab Sentronic manual selection,
steering wheel buttons optional
Single, dry-plate, diaphragm spring.
Front: MacPherson struts and gas shock absorbers.
Anti-roll bar. Hydroformed sub-frame.
Rear: Indep, four link, incl. toe-link. Coil springs.
Gas shock absorbers. Anti-roll bar. Sub-frame.
Rack and pinion, hydraulic power assistance.
Turning circle (curb to curb): 10.8 m (V6, 11.4 m)
Lock to lock: 2.75 turns (4-cyl turbo, 2.97 turns)
16 x 6.5˜, 215/55. 17 x 7.0˜, 225/45
17 x 7.5˜, 235/45. 18 x 7.5" , 225/45
Hydraulic, dual circuit, vacuum booster. ABS,TCS, MBA, EBD, CBC.
Discs: All 4 cylinder engines (except 2.0 Turbo):
285 mm (f) vent. / 278 mm (r) solid.
2.0 Turbo: 302/292 mm, both ventilated
2.8V6 Turbo: 314/292 mm, both ventilated
2.0 Turbo US model: 302 mm vent. / 278 mm solid
Kerb: 1585 -1690 kg
Distribution: 55%(F) / 45% (R)
Max. towing weight:
1600 kg (braked), 750 kg (unbraked)
Trunk: Soft-top up: 352 litres
Soft-top down: 235 litres
Fuel tank: 59 liters
Washer reservoir: 5.2 liters