Karsten Schebsdat, Head of Driving Dynamics, Steering and Control Systems. “The Golf GTI has always been a synonym for pure driving dynamics. This level of dynamism is one of the key features of the GTI. Few other vehicles in this category offer a similarly finely tuned balance between maximum sporty character and such high levels of travel comfort”, explains Volkswagen’s running gear expert Karsten Schebsdat. The engineer continues: “Considering the Golf GTI Mk7 already had very high levels of driving dynamics, we aimed to further enhance the driving pleasure of the Mk8 Golf GTI with an even more direct and agile steering response as well as vehicle handling. And we have succeeded.” Tighter driving dynamics properties guarantee a new, pure GTI experience. “We owe this enormous technological leap to elements including the new Vehicle Dynamics Manager which comes into its own in the Golf GTI. This higher-level control system centrally coordinates all electromechanical running gear functions,” Karsten Schebsdat says. “Thanks to the combination of new running gear setup plus front-axle locking differential and Vehicle Dynamics Manager we were able to elevate the Golf GTI’s outstanding overall performance to an even higher level. This applies all the more if the adjustable DCC running gear featuring a new software application is also on board,“ Schebsdat adds.
Evolved and new running gear systems in detail
Modifications to the front axle. The wishbone bearings, springs and buffer stops on the front axle have been reconfigured, as have the damping hydraulics. Its weight has also been cut by three kilograms thanks to a new aluminium subframe optimised to provide maximum rigidity. The front axle spring rate has been increased by five percent in comparison to the Golf GTI Mk 7.
Modifications to the rear axle. The rear axle also features a new wishbone bearing and spring setup. The auxiliary springs have also been reconfigured. The damping bearings are also new. As is the case for the front axle, the rear axle also features new damping hydraulics. the spring rate at the rear axle has been increased by 15 percent compared with the Golf GTI Mk7.
New Vehicle Dynamics Manager. The Vehicle Dynamics Manager coordinates and activates the functions of the electronically controlled front-axle locking differential, the electronic XDS differential lock as well as the lateral dynamic components of the optional electronically controlled shock absorbers (DCC) during every driving manoeuvre. In this process, adapting the individual wheel damping (200 times a second) guarantees particularly agile and accurate handling. Running gear engineers have introduced a new technical package to entirely eliminate understeer, a typical characteristic of front-wheel drive vehicles whereby the vehicle’s front wheels lose grip in quick corners. The Golf GTI races through corners extremely neutrally, even at suitably high speeds on race tracks, and also accelerates out of corners without any loss of traction. This is due in part to the fact that the locking torque of the front-axle locking differential can be significantly increased in Sport mode. Talking of race tracks, it is possible to adapt the ESC intervention in two stages. In ESC Sport mode the ESC thresholds and ASR slip thresholds are increased to reduce the intensity of interventions. In ESC Off mode, ambitious drivers can additionally deactivate ESC altogether. However, Front Assist and Swerve Assist reactivate ESC in emergencies.
Front-axle locking differential. As was previously the case in the Golf GTI Performance and the Golf GTI TCR (213 kW/290 PS), Volkswagen is now equipping the new Golf GTI with an electronically controlled front-axle locking differential as standard. Compared with fully mechanically operated differential locks, the system in the Golf GTI offers benefits including a variable degree of intervention, full integration into the Vehicle Dynamics Manager, and ESC, EDS and XDS+ functions. This makes it possible to completely avoid negative influences on steering precision, as is the case with mechanical locking differentials. Thanks to a multi-plate clutch, the locking differential optimises grip and handling in fast corners, thus enhancing the performance and ultimately providing additional driving pleasure. The front-axle locking differential eliminates front-wheel drive vehicles’ disadvantages in relation to grip.
Adaptive chassis control (DCC). Adaptive chassis control (DCC) continuously reacts to the road surface and driving situation while taking account of various elements including steering, braking and acceleration manoeuvres. By means of the set driving profile mode, the driver can influence the reduction in body motion as desired. The required damping is calculated for each wheel and adjusted at the four shock absorbers within fractions of a second. This ensures that DCC always provides the highest level of driving comfort and ideal driving dynamics in conjunction with the Vehicle Dynamics Manager. In the latest DCC generation, the vehicle setup can be extended in INDIVIDUAL mode to go beyond the existing range of the fixed COMFORT, ECO and SPORT modes. The driver can accurately set and store their personal driving profile using a digital slider. Beyond the COMFORT setting, the body is “decoupled” from the road surface as much as possible, thus boosting driving comfort. Beyond SPORT mode, there is an extended setting range with maximum damping for minimised body movements and extremely direct vehicle handling for that unbridled GTI feeling.
Progressive steering. Progressive steering is installed as standard in the new Golf GTI. This system has also been enhanced – running gear engineers set up the steering ratio more directly while applying new software algorithms and a new software application. How progressive steering works: conventional steering systems operate on the basis of a fixed gear ratio. However, the progressive steering in the Golf GTI applies a progressive gear ratio. This significantly reduces the effort required to steer when manoeuvring and parking. On winding country roads and when turning off, the driver will notice added levels of dynamism thanks to the more direct setup. It also means that the driver does not have to change their hand position as frequently. It takes a mere 2.1 turns of the steering wheel to turn it from stop to stop in the new Golf GTI. In terms of technology, progressive steering is essentially differentiated from the basic steering system by variable steering rack and pinion gearing as well as a more powerful electric motor. In contrast to systems with fixed steering ratio, which are always forced to compromise between driving dynamics and comfort, the gearing of the steering rack is considerably modified functionally using the steering stroke. Result: the transition between indirect steering response in the central range (driving straight ahead) and direct steering response in the event of larger steering wheel turn angles has been set up progressively to enable a considerably more agile steering response in situations demanding driving dynamics.