General Description (GNB)
General Description (GNB)
HiPerStrut Front Suspension:
The front suspension has 2 primary purposes:
* Isolate the driver from irregularities in the road surface.
* Define the ride and handling characteristics of the vehicle.
The front suspension absorbs the impact of the tires travelling over irregular road surfaces and dissipates this energy throughout the suspension system. This process isolates the vehicle occupants from the road surface. The rate at which the suspension dissipates the energy and the amount of energy that is absorbed is how the suspension defines the vehicles ride characteristics. Ride characteristics are controlled by the Electronic Suspension Control system. The Electronic Suspension Control system individually controls the damping force of each of the 4 shock absorbers. The suspension system must allow for the vertical movement of the tire and wheel assembly as the vehicle travels over irregular road surfaces while maintaining the tire's horizontal relationship to the road.
This requires that the steering knuckle be suspended between a lower control arm via the yoke assembly to the strut assembly. The lower control arm outermost point is attached to the yoke assembly and then through the king pin bushing to the steering knuckle. The innermost end of the control arm attached at 2 points to the vehicle frame through semi-rigid bushings. The upper portion of the steering knuckle is attached to the yoke assembly via a ball stud. The yoke assembly then connects to the strut assembly and vehicle body by way of an upper bushing. The steering knuckle is allowed to travel up and down independent of the vehicle body structure and frame.
This up and down motion of the steering knuckle as the vehicle travels over bumps is absorbed predominantly by the coil spring. This spring is retained under tension over the strut assembly. A strut is used in conjunction with this system in order to dampen out the oscillations of the coil spring. The strut is filled with oil and has a moveable shaft that connects to a piston inside the strut. Valves inside the shock absorber offer resistance to oil flow and consequently inhibit rapid movement of the piston and shaft. Each end of the shock absorber is connected in such a fashion to utilize this recoil action of a spring alone. Each end of the strut is designed as the connection point of the suspension system to the vehicle and acts as the coil spring seat. This allows the strut to utilize the dampening action to reduce the recoil of a spring alone. The lower control arm is allowed to pivot at the vehicle frame in a vertical fashion. The ball joint allows the steering knuckle to maintain the perpendicular relationship to the road surface.
Front suspensions systems utilize a stabilizer shaft. The stabilizer bar connects between the left and right strut assemblies through the stabilizer link and stabilizer shaft insulators. This bar controls the amount of independent movement of the suspension when the vehicle turns. Limiting the independent movement defines the vehicles handling characteristics on turns.
The advantage of the HiPerStrut front suspension (GNB) over the McPherson-type wheel suspension is less spindle length which leads to:
* Reduced smooth road shake
* Less torque steer
* Increased cornering power, no camber loss during cornering
* Robustness against wheel imbalance
All in all the HiPerStrut design provides improved ride and handling performance with a premium steering feel.
The design enables bigger wheels.
The design allows camber adjustment with screws on the steering knuckle upper ball stud.
1 - Upper Body Attachment (Same Points)
2 - Kingpin Axis
3 - Wheel Center
4 - Spindle Length
5 - Lower Body Attachment (Same Points)