ULEV II have been met with the help of:
•Four catalytic converters.Two of these are of Close Coupled Catalyst type and fitted to one exhaust manifold each. The other two are installed under the car floor.
•Higher idling speed at cold start, about 1250 r/min, and optimised ignition for faster warming of the engine at cold start and thus also the catalytic converters
•Lean air/fuel mixture for lower emissions at cold start
The result is extremely low emissions before the catalytic converters are activated – which takes place just 15 to 20 seconds after the engine starts up.
“It is during these 15–20 seconds that the majority of the emissions of environmentally harmful substances take place,” explains Jörgen Svensson.
The 4-valve engine also features continuous variable inlet and exhaust valve timing (CVVT). This system adjusts the valve opening times so they suit the engine’s current revs and load conditions. The engine is thus utilised more efficiently, cutting fuel consumption, lowering emissions and increasing performance
Distinct V8 sound
The Volvo XC90 V8 produces 315 horsepower and its torque – the most important characteristic of a V8 engine – is a massive 440 Nm at 3900 r/min. And at the sort of revs at which most driving takes place, around 2000 r/min, no less than 370 Nm of torque is at the driver’s disposal.
To increase the low end torque, the Volvo V8 has a valve in the inlet manifold that is closed below 3200 rpm. In this mode the air flow between the two cylinder banks is cut off, which creates a broader and more even torque curve.
“We chose to give our new V8 a sporty yet sophisticated appeal, with masses of power in reserve even as the revs rise,” explains Jörgen Svensson.
Acceleration from 0 to 100 km/h takes 7.0 seconds and fuel consumption is 13.0 litres/100 km (preliminary figures). Top speed is limited to 210 km/h (190 km/h in the USA).
The engine note is an important detail for buyers of a car with V8 power, and this is something to which Volvo Cars paid careful attention during the development of the new engine. In the hunt for that characteristic V8 rumble, it is the position of the inlet manifolds that is the main deciding factor.
“Our new V8 has just the right sort of charismatic off-beat V8 burble, but it is somewhat more muted in the European fashion rather than producing the more traditional meaty American throb.We feel this provides better audio comfort for the car’s occupants,” comments Jörgen Svensson.
New 6-speed automatic transmission
The power from Volvo’s V8 engine passes through an entirely new 6-speed automatic transmission dimensioned to handle the high torque. This unit too is of particularly compact dimensions so as not to interfere with the car’s overall structure. Sixth gear is a pure overdrive ratio to ensure quiet cruising and low fuel consumption.
“We get simply massive ‘take-off’ force with this auto transmission,” says Jörgen Svensson.
“And at the same time, it has a very sporty nature and does not change up in the middle of a curve, for instance, but instead stays in the same gear until the bend straightens out.”
The new 6-speed transmission is of Geartronic type, which means that it can also be shifted manually. There is also a possibility for Lock-up, and slipping Lockup, on all gears.
To ensure the optimum balance between driving properties, performance and fuel consumption the engine and transmission are treated as one unit. This is achieved with new software developed by Volvo, called CVC (Complete Vehicle Control). CVC is part of the integrated software package used, both in the engine control module and the transmission control module.
Among the many benefits of this approach was the possibility of integrating an overdrive 6th gear while still maintaining good driving performance by adjusting functionality, gear and torque to suit current conditions.
AWD with Instant Traction™ – a world innovation
The third ingredient in the new Volvo Cars V8 powertrain is the electronic AWD four-wheel drive system, which now features Instant Traction™. This new technology – which Volvo Cars is the first automaker in the world to introduce – improves the scope for quick getaways and provides enhanced traction on slippery surfaces. It has been developed by the Swedish company Haldex.
“A non-return valve allows us to use software to control the base torque that is programmed into the AWD system. When starting off from standstill, 80 Nm of torque is pre-charged in the system since the non-return valve prevents the unit from becoming totally drained of hydraulic fluid.
“This reduces the usual wheelspin of about one-seventh of a turn that the current system permits before the power is delivered to the rear wheels,” explains Jörgen Svensson.
The AWD system has also been upgraded to handle the power of the V8 engine. Maximum short-term torque at the rear wheels has been increased by 50 percent compared to current XC90
Specific V8 exterior design
“Masculine without being macho, powerful without being aggressive.” That was how Volvo Cars’ chief designer at the time, Peter Horbury, characterised the appearance and stance of the Volvo XC90 at its launch in 2002.
On the new XC90 V8, a V8 badge appears in the grille and on the tailgate to indicate the power under the hood. But there are also other design details that set the XC90 V8 apart.
•New 18" wheels
•Side mouldings and door handles painted in the car’s body colour
•Graphite-grey grille
•New chrome-plated trim around the bumper air intake
•New twin exhaust pipes
Volvo’s design department has also took considerable care over the appearance of the engine itself.
The V8 is the first example of a new design language for the engine compartment in Volvo’s coming models.
“We want there to be no doubt that this is a V8, and a modern and technically advanced V8 at that. We therefore chose not to hide the engine beneath large covers but instead to enhance the V-configuration and the eight inlet pipes,” says Anders Myrberg, head of engine compartment design at Volvo Cars.
On the inlet manifold, Volvo’s classic ‘iron’ symbol can be clearly seen in relief against a background of brushed aluminium and complemented with an elegant V8 emblem.