Published on May 15th, 2014 | by Daniel Sherman Fernandez0
Volkswagen Scirocco, Excitement At Every Corner
The Volkswagen Scirocco is available with a choice of two petrol engines with 3 stages of tune in Malaysia. These comprise a 1.4-litre twin-charged petrol unit producing 160 PS; a 2.0-litre turbocharged 200 PS engine; and of course the Scirocco we all want, the ‘R’ tuned version.
The TSI name represents all of Volkswagen’s pioneering forced-induction petrol engines which are available in the Scirocco. These engines produce high levels of power with low emissions from a relatively small capacity. Where FSI uses the direct injection of petrol into the combustion chamber to improve efficiency and hence reduce fuel consumption and emissions, linked to the 1.4-litre engine TSI takes this a step further and uses an FSI engine which is then dual-charged through a combination of an engine driven supercharger and an exhaust gas turbocharger arranged in series.
The driving characteristics of the TSI engines are improved over those of an FSI unit. The belt-driven supercharger operates at the lower engine speeds, with the turbocharger coming in as engine speed increases. The result of this is excellent driveability and performance throughout the range with no turbo lag and high maximum torque.
Key to the TSI’s success is that direct injection allows an abnormally high compression ratio of 10:1 to be used in conjunction with high maximum boost pressure of up to 2.5 bar absolute. This enables the relatively small engine to use very long gearing to provide exceptional fuel efficiency for a petrol engine, particularly at highway cruising speeds. As an additional bonus, the TSI engine provides driver enjoyment, producing high power and torque across a rev range from 1,000 to 6,500 rpm.
TSI technology has received international acclaim. After being recognised in the International Engine of the Year Awards since 2006 when it was named Best New Engine, in 2009 TSI technology won a trio of awards: the overall accolade of Best International Engine of the Year, Best Green Engine and Best Engine in the 1.0- to 1.4-litre category.
1.4-litre 1390 cc TSI, 16-valve 4-cyl, 160 PS
The 1.4-litre TSI unit available in the Scirocco uses supercharging and turbocharging to produce an impressive 160 PS at 5,800 rpm and 240 Nm of torque from 1,500 to 4,500. Linked to a seven-speed DSG automatic gearbox, the 1,390 cc engine accelerates from a standstill to 100km/h in an impressive 8.0 seconds and reaches a top speed of 135 mph. Combined economy is 44.8 while CO2 emissions are 147 g/km.
2.0-litre 1984 cc TSI, 16-valve 4-cyl, 200 PS
The Volkswagen Scirocco with a 2.0-litre TSI petrol engine linked to a DSG gearbox developes 200 PS from 5,100 to 6,000 rpm and 280 Nm of torque from 1,700 to 5,000 rpm, the 1,984 cc engine allows the Scirocco to achieve a 0 to 100km/h time of just 7.1 DSG before reaching a top speed of 145 mph. The combined fuel consumption figure for the vehicle is 37.2 mpg with CO2 emissions of 179 g/km.
6-Speed DSG – Direct Shift Gearbox
Volkswagen’s Direct Shift Gearbox was a true innovation, combining the comfort of an automatic gearbox with the performance and economy of a manual unit. The six-speed, transversely mounted DSG unit has two wet clutches with hydraulic pressure regulation. One clutch controls the ‘odd’ gears plus reverse, while the other operates the ‘even’ gears. Essentially it is two gearboxes in one. With this new clutch management system, the interruptions in power that are typical of even an automatic-shift manual gearbox no longer occur. This is achieved by an intelligent hydraulic and electronic (mechatronic) gearbox control system, the two wet-type clutches and the two input and output shafts in each half of the gearbox. The materials used for the friction surfaces are similar to those used in conventional automatic transmissions and are designed to last the life of the vehicle.
This combination enables the next-higher gear ratio to remain engaged but on standby until it is actually selected. In other words, if the car is being driven in third gear, fourth is selected but not yet activated. As soon as the ideal shift point is reached, the clutch on the third-gear side opens, the other clutch closes and fourth gear engages under accurate electronic supervision.
Since the opening and closing actions of the two clutches overlap, a smooth gearshift results and the entire shift process is completed in less than four-hundredths of a second. In addition to its fully automatic shift mode, DSG has a tiptronic function to permit manual gear selection.
The launch of the 1.4-litre TSI 160 PS unit in January 2009 marked the introduction to the range of a seven-speed DSG gearbox. This, another world-first for Volkswagen, uses a pair of dry clutches (as opposed to the wet ones in the six-speed version) to improve fuel efficiency and performance. The pair of dry, organic bonded friction linings do not require cooling, making the drivetrain more efficient through the extra gear ratio and the fact that less power is required for the gear selection and clutch servo system. Measuring only 369 mm in length and weighing only 79 kg including the dual-mass flywheel the gearbox is remarkably compact.
In adopting seven-speeds, Volkswagen engineers were able to lower first gear to improve acceleration from a standstill. By contrast seventh gear has been raised to act as an overdrive function making it ideal for motorway driving with the additional effect of raising economy and comfort levels. The volume of oil contained within the gearbox has also been reduced by 75 per cent. The oil circuits are split into two in an effort to protect the lubrication’s purity. As with a conventional manual gearbox, one of the circuits is used for cooling and lubrication of the gear teeth, the second feeds oil to the gear actuators. Since the clutch does not require cooling the quantity of oil was reduced from seven litres in the six-speed DSG gearbox to only 1.7-litres in the new seven-speed system.
Volkswagen’s Adaptive Chassis Control system – or ACC – which allows the driver to select from normal, comfort and sport settings to achieve the desired suspension, steering and accelerator response characteristics for their particular driving style.
The basic layout of the Scirocco’s suspension system was taken from the chassis of the Golf Mk V (the Golf that has lead the segment since it’s launch. This means strut-type suspension at the front and a multi-link layout at the rear. However the tuning of the springs, dampers and anti-roll bars was modified to suit the lower seating positions and the weight distribution of the Scirocco.
The VW Scirocco has a very low centre of gravity which presents some challenges. One of these is to retain adequate headroom for the occupants within the low overall vehicle height. Part of the solution is the incorporation of the tailgate hinges inside blisters in the roof, thereby allowing the roofline to be lowered and enhancing the dynamic appearance of the Scirocco without compromising practicality. The Scirocco has a significantly wider track than the Golf Mk VI. To increase track width and reduce unsprung mass, light alloy components are used in the rear. In line with its sporting aspirations the Scirocco is also tuned to offer the highest degree of stability for driving safety.
Volkswagen’s Adaptive Chassis Control – ACC
Engineers have in the past been constrained to design a suspension system which is biased either towards comfort or sportiness, always resulting in some form of compromise. The ideal, it was decided, would be to produce a chassis that could continually adapt to road conditions and the particular wishes of the driver or passengers. This has been achieved for the VW Scirocco, which features an Adaptive Chassis Control (ACC) system as standard on all models. Here not only can the suspension’s damping characteristics be controlled at the touch of a button, but the electro-mechanical power steering and accelerator response are also modified at the same time.
ACC operates via a set of four electrically adjustable dampers. Each damper is fitted with characteristic map control, a gateway control module that serves as an interface with the CAN data networks in the Volkswagen Scirocco – these comprise three sensors for measuring wheel displacement, three sensors for measuring movements of the body structure and a control module for the damping.
These sensors constantly measure the vehicle’s behaviour – be it under braking, acceleration or cornering – and react almost instantaneously to assure the optimum mix of chassis agility and comfort at all times. The vehicle defaults to ‘Normal’ mode in which the system strikes a balance for general use. Should the driver select ‘Sport’ mode the steering assistance is reduced, the damping is hardened and the throttle responses are sharpened as the mapping changes. This is intended for either twisty roads or track driving. In ‘Comfort’ the damping is softened and the steering assistance is increased to provide a smooth and controlled ride best suited to highway driving.