How the RS Torque Splitter of the new Audi RS 3 works

The all-wheel drive systems of Audi (call me and Quattro) ως αυτά της μάρκας που μας τη σύστησε, ουσιαστικά, ήταν πάντα θέμα συζήτησης.  Στα sports models the Audi RS 3 ήταν ανέκαθεν αντικείμενο ενδιαφέροντος (και ονείρων), αφού ήταν ένας “wolf in lambskin“.  Almighty engines, sound from another planet and alien performance, ήταν, είναι και, όπως φαίνεται, θα είναι τα χαρακτηριστικά του RS3.  Μόνο που σε αυτά, προστίθενται και άλλα, όπως η… time of joy (hyperbole).

In its next generation, the new RS 3, soon to be launched by Audi at a world premiere, is the first model of the brand that owns the RS Torque Splitter, a new torque distributor that shares the torque movement between the rear wheels by fully variable How. In combination with the five-cylinder engine power 400 HP, το compact σπορ μοντέλο υπόσχεται πως θα είναι εξαιρετικά ευέλικτο.  Και εξηγούμαστε: Η Audi υπόσχεται πως με τον νέο κατανεμητή ροπής, eliminates εντελώς ακόμα και τη… σκέψη subversion, ensures better grip in all conditions, promising best times on the track, while now releasing and drift mode για ελεγχόμενες πλαγιολισθήσεις όταν είναι… ώρα παιχνιδιού. Σε ό,τι αφορά τον κινητήρα και τις performance, ο 2.5 TFSI is now yielding torque 500 Nm, 20 Nm more than the previous model. The Audi RS 3 makes the sprint from standstill to 100 km/h in just under 3.8 seconds and reaches Final speed 290 km/h - class-leading performance. 

Το ερώτημα λοιπόν, είναι πώς “βγαίνει” αυτή η δύναμη στο δρόμο. Ο Meic Diessner, Audi's development and test engineer for the chassis and the Frank Stippler, race and test driver, who developed the car at the famous Nordschleife of the Nürburgring, explain a few key things about the torque splitter, just before the world premiere of the new RS 3 with this new technology. Let's see what and how below: 

How the torque distributor works

The RS Torque Splitter enables active, fully variable torque sharing between the rear wheels. In contrast to the rear axle differential and the previous multi-clutch package, the torque divider shall use one electronically controlled multi-clutch on each semi-axle. During dynamic driving, the torque divider increases the driving torque on the outer rear wheel with the highest load, which significantly reduces the tendency to reversion. Στις αριστερόστροφες καμπύλες, μεταδίδει τη ροπή στον δεξιό πίσω τροχό, στις δεξιόστροφες καμπύλες στον αριστερό πίσω τροχό και στην ευθεία και στους δύο τροχούς. Αυτό έχει ως αποτέλεσμα τη βέλτιστη σταθερότητα και τη μέγιστη ευελιξία – ειδικά σε high-speed revs. During the driving on closed tracks, the torque distributor allows controlled movements by applying all the power of the engine to a μόνο από τους πίσω τροχούς – έως και 1,750 Nm of torque. The exact torque distribution always depends on the mode selected in Audi drive select and the corresponding driving mode.

Each of the two multi-disc clutches has its own control unit, which uses the wheel speed sensors the electronic stabilisation control, to measure the wheel speeds. Other influencing factors include longitudinal and lateral acceleration, steering angle, throttle pedal position, selected speed and angle of deflection, i.e. rotational movement about the vertical axis. In addition, the torque multiplier is connected to the modular vehicle dynamics controller for even better control.

Why the torque splitter improves driving performance

Due to the difference in propulsion forces, the car takes the corner even better and follows the steering angle precisely. This results in less backfeed, faster acceleration that occurs earlier at the exit από τις στροφές, και ιδιαίτερα ακριβή και ευέλικτη συμπεριφορά – για πρόσθετη ασφάλεια στην καθημερινή χρήση και fastest lap on the track. The torque divider also compensates for the hyperventilating, directing the torque to the wheel inside the curve or, if necessary, to both wheels.

Μιλώντας για επιτάχυνση – τι νέο υπάρχει για τον κινητήρα και το κιβώτιο ταχυτήτων;

Ο five-cylinder in the new Audi RS 3 is more powerful and offers more torque. Instead of 480 Nm, the maximum of 500 Nm είναι τώρα διαθέσιμο – σε ένα ευρύ φάσμα στροφών from 2.250 to 5.600 rpm A new engine control unit also increases the speed and intensity with which all engine components communicate with each other. As a result, the RS 3 responds even faster, especially in low rev ranges. The maximum power of the 400 hp (294 kW) is now available in the region from 5.600 to 7.000 rpm and therefore earlier and longer than in the previous model. As a result, the compact sports car accelerates 0-100 km/h in 3.8 seconds, 0.3 seconds faster than before. The Sedan and Sportback reach their top speed in 250 km/h, although the 280 km/h are also available, optional. In fact, with the RS Dynamic package and the ceramic brakes, they can even reach a top speed of 290 km/h. This makes the RS 3 best in class in terms of acceleration and top speed. The 7-speed dual-clutch transmission θέτει αποτελεσματικά τη δύναμη του πεντακύλινδρου κινητήρα στον δρόμο – με πιο στιβαρό σχεδιασμό που λαμβάνει υπόψη την αυξημένη ροπή και την πιο σπορ αναλογία σχέσεων μετάδοσης. Η έξυπνη αλληλεπίδραση όλων των στοιχείων του κινητήρα, συμπεριλαμβανομένου του launch control, allows the RS 3 to change gears very quickly, resulting in quick starts and acceleration that gets the heart beating faster.

What role does the modular vehicle dynamics controller;

After its use in A3 and S3, the modular vehicle dynamics controller (mVDC) also ensures that the framework systems interact more accurately and faster in the new RS 3. To do this, the central system captures data from all components related to the lateral dynamics. The mVDC synchronizes the two torque control modules, the adaptive dampers and the torque control on each wheel for high-precision driving and handling. Overall, it increases the flexibility of the entire vehicle, especially on dynamic routes.

What effect does the Audi drive select on driving performance?

The Dynamic Steering System Audi drive select in the new RS 3 offers seven functions: Comfort, Auto, Dynamic, Efficiency, as well as RS Individual, RS Performance and RS Torque Rear. Depending on the selected mode, the characteristics of the driveline and chassis components change from emphasis on the comfort at extremely dynamic, even optimized on the track Performance. In addition to the torque splitter, Audi drive select also has an effect on the engine and gearbox characteristics, power steering, adaptive dampers and on the exhaust fins. Different characteristic curves for each of the aforementioned systems create a wide range of driving experiences.

In RS Individual mode, each system can be individually configured within its predefined characteristic curves. At Dynamic function, all the elements have been shaped for sporty driving. The driver feels this with a more responsive steering response and highly responsive handling for dynamic driving, with a clearly perceptible engine sound. The Changes gearbox of the S tronic is shorter, the acceleration even sportier. The ultimate in dynamic behaviour can be experienced in Dynamic mode and in the new, RS 3-specific mode RS Torque Rear.

How is the torque divider integrated into the dynamic steering system?

Το Audi drive select τροποποιεί τα χαρακτηριστικά του κατανεμητή ροπής και έτσι και τον χειρισμό του αυτοκινήτου ανάλογα με την επιλεγμένη λειτουργία. Πέντε χαρακτηριστικές καμπύλες – Comfort/Efficiency, Auto, Dynamic, RS Performance και RS Torque Rear – αποθηκεύονται στο σύστημα. Σε αυτό το πλαίσιο, η ισχύς του κινητήρα κατανέμεται on all four wheels in Comfort/Efficiency modes, with priority on the front axle. In the function Car, the torque distribution is balanced, which means that the RS 3 does not subvert nor does it overshoot. Η Dynamic function, on the other hand, tends to transmit as much torque as possible on the rear axle – για μέγιστη ευελιξία και αυξημένη δυναμική. Αυτό φτάνει στην τελειότητα στη λειτουργία RS Torque Rear, which allows the driver to perform controlled sideways slides on a track. The rear axle-focused power distribution of the engine leads to hypertrophic behaviour, with up to 100% of drive torque be directed backwards leading to the wheel on the outside of the curve. In addition, Audi has adapted the characteristics of the engine and gearbox. This particular setup is also used by the RS Performance Mode, which is designed for the track. It is specially tuned to the semi-slick performance tyres Pirelli P Zero “Trofeo R”, which are optionally available for the first time from the factory. In this mode, the torque splitter provides a particularly dynamic, sporty longitudinal axis ride with as little understeer and oversteer as possible. This results in fast acceleration at the rev outputs and thus best lap times.

Ηλεκτρονικός έλεγχος σταθεροποίησης – ενεργοποιημένος, Sport or disabled?

The electronic stabilisation control (ESC) στο RS 3 έχει προσαρμοστεί ειδικά στον κατανεμητή ροπής, την ανάρτηση, τα ελαστικά και τους νέους τρόπους οδήγησης RS. Λειτουργεί ακόμα πιο γρήγορα και με μεγαλύτερη ακρίβεια από ό,τι στο προηγούμενο μοντέλο. Το ESC μπορεί να ρυθμιστεί σε λειτουργία Sport και η λειτουργία οδήγησης απόδοσης RS έχει οριστεί σε ESC Sport στο εργοστάσιο. Για ιδιαίτερα σπορ οδήγηση – σε πίστες, για παράδειγμα – το ESC μπορεί επίσης να απενεργοποιηθεί εντελώς κρατώντας πατημένο το κουμπί στην κεντρική κονσόλα για περισσότερο από τρία δευτερόλεπτα.

Μεγαλύτερη ακρίβεια, μεγαλύτερη σταθερότητα – πώς διαμορφώνονται τα αμορτισέρ;

The standard RS sports suspension features new shock absorbers and valve system, both specifically for the RS 3. The valves ensure that the shock absorbers have a particularly sensitive response as part of their characteristics. This allows the suspension to respond to the respective driving situation even faster and more efficiently.

The sports suspension RS plus with adaptive damper control available as an option. It continuously and individually adjusts each shock absorber to the road conditions, driving situation and mode selected in Audi drive select. The three characteristic curves comfortable, balanced and sporty provide a clearly perceptible experience of the shock absorber characteristics. The ideal damping force is calculated within milliseconds – χαμηλή for bumper cars, high for supporting the vehicle body during fast cornering or braking. To do this, the sensors measure the vertical acceleration of the bodywork and the movement of the individual wheels in relation to it. This results in increased dynamics and excellent driving stability with even greater comfort compared to the RS sports suspension. In RS Individual mode, the shock absorbers can be configured according to individual requirements and road conditions within the three characteristic curves. In RS Performance mode, there is a special comfort setting for the shock absorbers that minimises vertical excitation και παρέχει τη βέλτιστη υποστήριξη για ομαλή πλευρική δυναμική – ιδιαίτερα suitable for track with uneven surfaces, such as the Nordschleife.

What other elements contribute to increasing driving dynamics?

Η adjustment of springs and shock absorbers is extremely hard and the body is ten millimetres lower from the Audi S3 and 25 mm lower than in A3. This lowers the vehicle's centre of gravity further towards the road. Installed at the front is a McPherson knee suspension with RS 3-specific rotary bearings, reinforced lower swingarms, subframes and stabilizers. To increase cornering power, i.e. to provide more grip on curves and more dynamic cornering, the Audi RS 3 has just under half a degree of additional negative camber compared to the A3. This increased slope to the road surface, i.e. the greater angle between the wheel and the vertical, also results in a more precise steering response. Ο rear axle Features four link design with a separate shock absorber assembly, subframe and tubular anti-roll bar, mounted on the torque converter. The reinforced wheel carriers increase the lateral dynamics as well as the response to steering movements and thus the vehicle's manoeuvrability.

Το προοδευτικό τιμόνι ειδικά για το RS μεταβάλλει την σχέση μετάδοσης ανάλογα με τη γωνία διεύθυνσης – καθώς η γωνία διεύθυνσης αυξάνεται, ο λόγος του μηχανισμού γίνεται μικρότερος και η οδήγηση πιο άμεση. Βοηθά επίσης με βάση την ταχύτητα και μπορεί να μεταβληθεί μέσω του Audi drive select μέσα στις τρεις χαρακτηριστικές καμπύλες άνετη, ισορροπημένη και σπορ. Με αυτόν τον τρόπο, ο κατανεμητής ροπής και τα υπόλοιπα καινοτόμα εξαρτήματα του οχήματος βάζουν τέλεια τη δυναμική ισχύ του νέου Audi RS 3 στον δρόμο, σε κάθε οδηγική κατάσταση.