A drive system that distributes power evenly among the wheels for dynamic handling, greater safety, and superior distribution. In order to provide excellent traction and completely eliminate understeer, sport differential transfers torque from the engine between the rear wheels.
Driving on rails is one thing, but this is another. As a result, the driver has more control and is safer thanks to the Audi quattro with sport differential system, which distributes power between the rear wheels for optimal distribution and dynamic handling. Sport differential evenly distributes torque to all four rear wheels to maximize traction and completely eliminate understeer.
In This Article...
Audi differential – what is it?
Some Audi vehicles, including the S4, S5, and A8, come with an optional quattro Sport Differential.
Depending on the amount of available traction, these cars’ standard quattro all-wheel drive technology can alter the ratio of torque supplied to the front and back wheels. More power is given to the front wheels when the rear wheels begin to slide, and vice versa.
Similar in operation, the Sport Differential shifts the torque distribution in the rear axle from side to side by means of torque vectoring. To help the car turn into a corner, extra power is applied to the outside rear wheel. The Sport Differential helps the car rotate and removes understeer, which is the front end pushing wide. To keep the car on the right course, the system cooperates with the traction control (ASR) and stability control (ESP) systems. The Sport Differential can be altered along with the engine, transmission, suspension, and steering settings thanks to the differential’s compatibility with Audi’s drive choose system.
How can I find out if the sport differential is in my Audi S4?
On the center stack’s bottom left side, the sport diff automobiles have a small drive select spot. It ought to be specified in the car’s description what features it contains, such as a sport differential or anything else.
What is the adaptive damping suspension for Audi Sport?
For specific Audi RS models, sport suspension plus with Dynamic Ride Control (DRC) is a highly dynamic dampening technology. The driver can change the single-tube dampers’ variable characteristic in three steps. Shock absorber pairs that are diagonally opposed to one another are connected by hydraulic lines and a central valve. The valves control the oil flow in the shock absorber of the front wheel with the spring deflection when cornering quickly. They give more support and lessen pitch and roll motion. This enhances handling by allowing the car to follow the road more closely.
Dynamic steering
Depending on the driving speed, steering angle, and chosen mode in the Audi drive choose handling system, dynamic steering can change the steering ratio by up to 100%. The superimposition gearing in the steering column, which is powered by an electric motor, is the main part. Its design, known as strain wave gearing, is small, light, and torsionally stiff. It has little friction, is precise, and is free of play. The gearing is highly efficient and capable of transferring large torques very quickly.
The strain wave gearing only needs three essential parts to function. A thin-walled sun wheel is deformed by an electric motor rotating an elliptical internal rotor, which is coupled to the steering input shaft by a ball bearing. It meshes with a hollow wheel with a sprocket that works on the steering output shaft at the vertical axes of the ellipse. The internal rotor’s rotation causes the ellipse’s large axis to move into the area where the teeth engage. The sun wheel and hollow wheel move in relation to one another because the sun wheel has fewer teeth than the latter. The fast-running electric motor’s huge gear ratio makes it feasible to build up this ratio precisely and quickly.
Dynamic steering works very directly when driving at moderate speeds in city traffic and when navigating; it only requires two complete revolutions of the steering wheel to move from one end stop to the other. Because of the substantial power steering increase, parking maneuvers are incredibly simple. The directness of the steering reaction and the steering power assist gradually decrease on country roads. Indirect gear ratios and low power assist are employed at high expressway speeds to calm down jerky steering movements and permit excellent straight tracking.
To accomplish sporty handling and driving safety, dynamic steering tightly cooperates with the electronic stabilization control program, or ESC. It countersteers slightly if necessary; in the vast majority of circumstances, its minimal interventions, the most of which are undetectable to the driver, mitigate understeer and oversteer caused by load changes. The technology assists with stabilizing steering inputs when stopping on surfaces with divided friction coefficients.
Dynamic steering can make corrections more quickly than the brake system can increase wheel pressure. The principal workbrake operations it handles frequently either stop being necessary or are reduced to dampening effects that slow down driving. At high speeds and on slick terrain like snow, the benefits in terms of driving safety and sportiness stand out the most.
Electrohydraulically integrated brake control system
The Audi e-tron is the first electric series production car to feature a brake control system that is electrohydraulically integrated. Hydraulic, electrical, and electronic actuators are used to operate the wheel brakes, reinforcement, and activation, respectively. Within milliseconds, the control unit determines how hard the driver is pressing the brake pedal and calculates how much braking torque is required. If the recovery torque is insufficient, more hydraulic pressure for the traditional friction brake is produced. The displacement piston, which is propelled by an electric spindle drive, forces braking fluid into the brake lines. The driver is not aware of the seamless change from the engine brake to the pure friction brake. The familiar pedal sensation for the driver’s foot is produced by a second piston using a pressure-resistant component. The brake pedal simulator ensures that the driver is not impacted by hydraulic issues. When ABS is used to brake, pressure buildup and decrease do not manifest as grating, loud pulsations.
When the driver presses the left pedal firmly enough to cause a deceleration greater than 0.3 g, the electrohydraulic brake system is engaged; otherwise, the Audi e-tron slows down using recuperation from its two electric motors. The brake control system precisely and nearly twice as quickly as a conventional system builds up brake pressure for the wheel brakes. There are only 150 milliseconds between the start of the brake application and the presence of the maximum brake pressure between the pads and disks when automated emergency braking is used. Impressively low braking distances result from this, which takes hardly longer than a blink of an eye. Because wheel brakes are more effective than electric braking in this situation, the car decelerates even at extremely low speeds, such as those experienced during maneuvering. Otherwise, the electric motor would have to actively slow down at low rotational speeds, draining important battery current.
The electrohydraulically integrated brake control system’s “brake-by-wire technology” permits a bigger air gap, or a greater separation between the brake pad and brake disk, to be adjusted. As a result, the likelihood of friction and heat generation is reduced, actively extending the vehicle’s range.
Electromechanical active roll stabilization
With electromechanical active roll stabilization, a wide range between smooth build-up and lively handling is guaranteed. Between the two stabilizer portions on each front and rear axle is a small electric motor with a three-stage planetary gear set. The suspension control makes sure that both stabilizer halves behave mainly independently of one another when traveling straight ahead. This improves ride comfort by lowering vibrations caused by sprung mass on uneven roadways. However, at fast speeds, the goal is to achieve the best roll compensation. The transmission of the electric motor rotates the stabilizer’s halves in opposite directions as a unit, reducing the roll angle when cornering and making the car’s handling even more firm and dynamic.
Electromechanical active roll stabilization serves as a recuperative system and is powered by a strong 48-volt electrical subsystem: The stabilizer is excited when the wheels on one axle deflect to significantly different degrees as a result of road imperfections; the electromechanical active roll stabilization motor now turns each impulse into electrical energy. The lithium-ion battery of the electrical subsystem stores this energy, making sure that the electromechanical active roll stabilization has a much better overall energy balance than a hydraulic system. Active roll stabilization also requires minimal maintenance because it doesn’t utilize oil.
Electronic chassis platform
The electronic chassis platform (ECP) serves as the chassis’ main control panel. It keeps track of the vehicle’s speed, height values, vertical, roll, and pitch motions as well as the road’s coefficient of friction and the current driving condition, such as under- or oversteer, as well as information on the associated suspension systems. It swiftly determines and carefully coordinates the optimal function of these components based on these. The consumer notices ride characteristics more clearly as a result of the central control, including accurate cornering, enhanced dynamics, and a high level of ride comfort.
Adaptive air suspension
Adjustable air suspension A regulated damping air suspension system offers a wide range between comfortable cruising and competitive performance. It independently changes the ride height based on the speed and the driver’s preferences and the road conditions. As a function of load, the air suspension also provides level control.
Various specific product lines have different system designs. Shock absorbers are enclosed by air springs in the front suspension struts. These two parts are often applied individually in the rear suspension of vehicles. However, pneumatic struts are also mounted on the rear suspension of the Audi A8 (2017). Depending on the type, the compressor’s mounting position and the quantity of pressure reservoirs that must be filled also vary.
The electronic chassis platform (ECP), the primary chassis control unit, individually regulates the operation of each wheel’s shock absorbers at cycles in the order of milliseconds depending on the state of the road, the driver’s driving technique, and the mode selected in the Audi drive select dynamic handling system. The hydraulic fluid’s volumetric flow is adjusted using solenoid damper valves.
What is dynamic steering in an Audi?
a steering ratio that is influenced by the vehicle’s speed and steering torque, improving steering accuracy and quickening steering response.
instantaneous response from the steering. Boost steering response time and steering accuracy. In order to promote driver confidence and straight-line directional stability, Audi dynamic steering utilizes a more indirect steering ratio. At low to medium speeds and during parking, a direct or nearly-direct ratio is employed to manage tight curves more readily.
What makes B8 and B8 5 different from one another?
2009 saw the introduction of the Audi B8 A4, which was produced until 2012 before being replaced by the B8.5 A4.
Let’s first examine the distinction between the B8 A4 and S4. Here, you can observe the minor difference between the lower grille on the S4 and the A4, with the latter having ‘fins’ that extend onto the bumper.
Look at the B8.5, A4, and S4 now. The bottom fog light grills have undergone a much more subtle alteration. The ‘bend’ in the strip that runs horizontally over the fog light grill is different since it is not straight. And in the bottom image, we can see the B8.5 Audi’s alternate grille option, which is totally mesh rather than having horizontal slats.
The front end of the B8.5 models has been entirely overhauled, adding new headlights, grille, fog lights, a new bumper, hood, and fenders.
Please be aware that without a complete front-end switch, the parts of the B8 and B8.5 front ends are not interchangeable.
The B8.5 also has electromechanical steering in addition to a redesigned, lighter center differential with crown gears. The B8 features hydraulic steering, however.
Last but not least, the B8.5 gets a small modification of a number of interior components, including the climatronic and plastic dash surround.
What causes the magnetic ride in an Audi?
Audi Magnetic Ride is a device that uses a magnetic field to change the shock absorber’s hardness. Depending on their intended driving style, drivers can select either a comfort mode or a sport mode using the system. The magnetic particles in the shock absorber fluid are aligned against the shock absorber’s motion by the application of a magnetic field; the stronger the magnetic field, the greater the damping force. Based on data from the wheel travel sensors, ESP, and steering system, the system can react to various driving situations nearly quickly and give the correct amount of damping.
You most likely have a bad ball joint if you hear popping sounds when turning or going over bumps. Lifting the front tires off the ground and shaking the front wheels side to side is the simplest technique to inspect. A ball joint has play if you hear or feel a popping or clicking sound, and the entire arm needs to be replaced. Put your palm over the ball joints to feel which one is popping to identify which ball joint it is.
Your bushings may be the cause of your suspension feeling sloppy or hazy. The upper arms break down frequently, and you may detect when they need to be replaced by performing a quick visual inspection. Turn the wheels from lock to lock while they are off the ground, checking the bushings along the way. Rubber should be replaced if it has severe tears or deep fissures.
I advise utilizing high-quality components, as with all suspension repairs, and having an alignment done thereafter. Put everything back where it was removed from in order to properly preload the bushings and prevent early wear on them. If your suspension doesn’t track straight and wears down your tires, there’s no point in replacing it with a component costing hundreds of dollars. Your Audi or Volkswagen’s suspension will take care of you if you take good care of it.
Not only Audi employs multi-link suspension, so what are your personal experiences?
Authored by:
Chris is a journeyman mechanic from Berkeley, California, specializing in late model Volkswagens and Audis. A glutton for punishment, his spare time is spent rebuilding every component of his ’83 Rabbit GTI.