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Golf V Part V: Chassis and Production

Below is the full Volkswagen AG press kit broken down into multiple sections with over 150 photos. The press release, while applicable to the Golf V in general, does contain model specific details for the German market, so expect some detail changes on North American specification models.

CHASSIS

Dynamic revolution thanks to new multilink rear axle

 

New Golf’s safety chassis lays down long-term benchmark

Electromechanical power steering delivers pure unadulterated driving pleasure

Volkswagen has configured the new, dynamic safety chassis so it is just as sporty as comfortable. A much-improved suspension-strut-type axle is used at the front and a newly developed multilink axle is used at the rear. Thanks to the multilink axle (four-link suspension), handling and driving comfort have been decisively improved. Active safety also benefits from the new axle configuration. As inclined dampers with oval auxiliary springs are also used in the new Golf, the through-loading width in the luggage compartment has been enlarged. The optimised front axle provides better handling dynamics in corners through a reduction in lateral inclination and the improved response of the anti-roll bars. In addition to that, the more precise wheel location and optimised suspension response contribute to a noticeable improvement in overall comfort.

Handling and comfort have been optimised by an electromechanical steering system which not only offers power assistance as a function of road speed, but also contributes significantly to straight-line stability. The fuel consumption of the Golf has also been reduced by approximately 0.2 litres through the new steering.

The new Golf is equipped as standard with the latest generation of ESP and “Dual Brake Assist”. A, likewise newly designed, brake system with optimised cooling provides the basis for excellent deceleration values. All in all, the Golf chassis offers an extremely successful synthesis of driving comfort across all classes while at the same time achieving highly dynamic steering and handling performance.

 

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The multilink rear axle

 

The multilink rear axle: combination of driving comfort and optimum handling

The central development goal for the Golf’s chassis was clearly to bring about an as yet in this vehicle class unrealised alliance of cross-class driving comfort and ultimate handling performance. Handling performance should also be characterised by outstanding driving safety and exact precision with high levels of agility.

The ideal preconditions for implementing these goals have been created through the use of a suitably improved suspension-strut-type front axle with lower A-arm and the completely new four-link rear suspension. Because it has been possible to implement all the requirements optimally and conclusively with these axle concepts.

The dynamic character of a vehicle is determined substantially by the design of the rear axle. Providing outstanding handling dynamics while simultaneously maintaining high levels of driving comfort inevitably necessitates the use of a costly multilink design. This is because, in the case of the multilink axle, longitudinal and transversal dynamics can be configured specifically and virtually independently of each other.

The wheel variables relevant to transversal dynamics such as track and camber are crucially defined under acting forces with the three wishbones and their meticulously matched bearings. The longitudinal movement of the wheel is essentially determined by the kinematics of the trailing arms and the resilient behaviour of the large-volume bearings. The braking moment that occurs is supported via the trailing arm. The axle, which is designed to understeer slightly, supports the agility of the steering performance and increases stability under braking. The almost neutral layout gives rise to very good straight-running stability characteristics on highly uneven road surfaces. The tyre wear is also minimised.

The trailing arm bearing is -even with regard to an optimum vehicle package – secured to the highest possible point. The high position of this bearing on the one hand results in very high anti-dive (anti-lift) but on the other hand optimises rolling comfort as well. In addition, the steering performance of the axle has a stabilising effect under acting longitudinal forces: there is slight toe-in steering during braking. The upshot of this is that turning-in of the car is reduced while braking in corners.

The steering effect of the axle is configured to be load-dependent. The different requirements depending on the load state have been implemented in the best way possible by polished kinematics/elastokinematics: slight toe-in steering at the outer wheel promotes agile and stable handling performance at low load. Heavier toe-in steering at high load ensures a level of driving stability that has not been attained before in this class. The high transversal rigidity of the axle in combination with the lateral-force-understeering learning effect of the axle for the laden vehicle provide the optimum basis for high driving stability.

The longitudinal compliance characteristic of the axle is significantly influenced by the design of the trailing arm bearing. The relevant bearing identification is soft with regard to an optimum compression characteristic. Even large longitudinal forces are well damped as a result of its slightly progressive characteristic. The spread effected with the multilink suspension between a comfort-related, low longitudinal compliance characteristic and dynamically important high transversal rigidity takes on a special position in the face of the Golf’s competitors.

 

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The much improved suspension-strut-type front axle

The much improved suspension-strut-type front axle: more agile, precise and comfortable than ever

Numerous details optimise the tried-and-tested Gold front axle. The most striking improvements on the front axle are set out below.

Increase in agility and improvement in steering precision through:

- more direct steering ratio

- higher transversal axle rigidity under lateral force at the tyre contact point

- lower tendency to roll due to highly effective stabiliser bar connection.

Increase in rolling and driving comfort through:

- optimisation of oblique springing

- new mounting concept for the lower wishbone

- separate mounting of spring and damper on the suspension strut tower

- newly developed twin-sleeve shock absorber

By ideally matching the optimised front axle to the new multilink rear axle, Volkswagen has made a technical generation leap in the chassis field. In other words: with its new multilink suspension, the new Golf is laying down the benchmark in its class in the fields of handling dynamics, driving safety and driving comfort.

New electromechanical steering

 

New electromechanical steering: noticeably more driving pleasure thanks to a direct steering feel

The new Golf exhibits extremely harmonious steering performance. And there’s more: it conveys a distinctive steering feel, from which the driver derives increased safety and pleasure while driving. This feeling of safety and confidence in the steering wheel can be put down to the newly developed electromechanical power steering (EPS). On top of numerous dynamic benefits, the new steering system also reduces fuel consumption: because, in contrast to a conventional hydraulic solution, the electromechanical system only “works” in the event of a steering angle, average consumption in real driving drops by roughly 0.2 litre.

Particular attention has been given in this system’s development to the so-called “centre feel” in straight-line driving. The steering torque that already builds up at the smallest steering angles is emphasised by the exact centre feel. The active return tendency of the steering is also responsible for this effect; after cornering, the steering wheel automatically tries to return to the direction of straight-line driving.

In addition, the “self-learning” steering also features a straight-line correction function. Background: the system itself recognises inclined road angles and countersteers accordingly. The straight-line correction function thus provides a significant increase in comfort and convenience as the driver is able to keep the Golf on course in a relaxed manner without exerting steering force.

The steering system’s Servotronic also offers excellent options for configuring the most varied steering parameters:

- Low torques when moving at extremely low speed make it easier to manoeuvre when parking and in city traffic.

- Higher torques convey maximum “feedback” to the driver when travelling at high speed.

The following examples also show how perfectly the steering can be individually adapted to every conceivable requirements: in order to guarantee a permanently uniform steering characteristic, different support maps are required on account of the broad fluctuation in front axle loads caused by the wide range of different engine, gearbox and equipment combinations. For this reason, all the axle-load-dependent maps are already preprogrammed and stored in the steering control unit. The individual steering programming is activated virtually at the touch of a button at the final stage of production.

Thanks to the system’s programmability, it is also possible to adapt the steering easily and optimally to a broad spectrum of vehicle characteristics ranging from sporty through comfortable right through to particularly easy steering for handicapped drivers.

 

The new Golf’s brake system

The new Golf’s brake system: optimum response with ideal proportioning and a completely new ESP round off active safety to perfection

The fifth-generation Golf is equipped with a newly developed brake system. Integral to the brake system here -and standard for the marque -is ABS plus ESP complete integrated Dual Brake Assist. The brake system is notable for its outstanding stability, ease of operation, short response times and generally extremely short braking distances. The development team has succeeded in resolving the design conflict of having supremely quick brake response with simultaneously excellent proportioning by introducing a newly designed 10-inch brake servo.

Ventilated disc brakes are deployed on the front axle of all the Golf versions. Depending on the engine type, these brakes range in size from a 15-inch disc (diameter: 280 mm) to a 17-inch disc (diameter: 345 mm) for the future top-of-the-range engines. The brake discs on the rear axle in the basic version have a diameter of 255 millimetres while for the most powerful engine solutions the diameter increases to 286 millimetres.

Brake response is rounded off to perfection by a new ESP generation too. The Electronic Stabilisation Program has a range of new features which have a direct and positive effect on the active safety of the new Golf. These features include:

- AEM (Adaptive Engagement Model) -the car is continuously monitored even when it is travelling in a stable manner. In this way, the system can take fast corrective action if the car becomes unstable.

- LDE (Low Dynamic ESP) -can already intervene in the event of minor deviations in the braked driving state even though the car is still travelling in a stable manner.

- HVV (Maximum Rear Axle Deceleration) -actively increases the pressure on the rear axle into the ABS control operation if the front wheels are already subject to control in the ABS range but the rear wheels are not.

The new ESP generation always comprises the following functions:

- ABS (Anti-lock Braking System)

- AEM (Adaptive Engagement Model)

- ASR (Traction Control)

- EBD (Electronic Brake Pressure Distributor)

- EDL (Electronic Differential Lock)

- ESBS (Extended Stability Brake System)

- HBA (Hydraulic Brake Assist)

- HVV (Maximum Rear Axle Deceleration)

- LDE (Low Dynamic ESP)

- EBC (Engine Braking Control)

- Overboost (Hydraulic Auxiliary Boosting)

PRODUCTION

Perfection rolling off the production line

In Germany alone the Golf provides 10,000 jobs

Golf will be produced in Germany and Belgium during the start-up phase

The Golf is a key factor for the attractiveness of Germany as a production location. Should Wolfsburg, home to Volkswagen AG and the world’s largest automobile production plant, be referred to as “Golfsburg” in the headlines during the launch phase of the new model from August 25, this is not so much a marketing idea as a reflection of the city’s gratitude. For the Golf plays a major role of the economic engine in this city. At the parent plant in Wolfsburg, approximately 20,000 employees are directly involved in the production, development and distribution of the best-selling model. In and around Wolfsburg, 100 suppliers and businesses of every description are involved in the production of the Golf.

The Golf is also produced in Mosel (Saxony) as well as in the Belgian city of Brussels and will at a later date be produced in the South African city of Uitenhage

The new Golf is produced in halls 1 (Press shop), ¾ (Bodyshop), 15b (Paint shop), 54 (Assembly) and 12 (Production line roll-off) on state-of-the-art production systems and using modern assembly sequences and technologies, such as laser welding. The production change-over for the new generation began at a very early stage, thus ensuring an optimal production ramp-up . The Golf is also produced in parallel at the Mosel Volkswagen plant in Saxony. On top of that there are two international production locations for the Golf: the Brussels plant in Belgium and – with a time delay – the Uitenhage plant in South Africa.

Irrespective of where the Golf is produced, the production process sets new standards. The proportion of high-strength body panels for example has again risen significantly. The net result is a significant plus in terms of body strength, crash safety and comfort whilst optimising weight. For example the laser-welding process: 140 special robots ensure the high body rigidity of the Golf, among other things, by means of laser-welded seams with a total length of 70 metres, as compared to five metres in the predecessor. Take quality assurance for example: as one of the last of many checks, electronic and electrical components are checked in the so-called “Try Out Room”. The final step is a 10-minute test on the “running-in stand”.





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