Suspension setup for the Nürburgring Nordschleife differences to regular race tracks

Transcription

1 Suspension setup for the Nürburgring Nordschleife differences to regular race tracks Dipl.-Ing. Andrei Filep, November 15 th 2012

2 Content: - Team Tuning Akademie / development topics - Technology platform Audi A4 quattro - References - Suspension tuning - Summary

3 Members of Tuning Akademie are: - Engineers and technicians of technical development ( Aachen department of Audi AG and ika (RWTH Improvement of Brake and suspension items for special requirements Development and verification of chassis control systems Alternative fuel and efficiency concepts Development Integration and adaption of innovative concepts into the technology plattform Gathering measurement data under reproducable conditions Information transfer of alalysing resultes to project partners Races Testing of innovative technologies under racing conditions Representation of new technologies and project partners in public view Exhibitions/Publications Support in communication of new technologies and analysing results from scientific point of view Scientific publications of these technologies during scientific conferences and exhibitions

4 Technology platform Audi A4 3.0 TDI quattro body: Audi RS4 (B7) engine: V6 TDI (Generation 1) capacity: power: torque: tires: brakes: ABS / ESP: Technical data 2967ccm 230 kw 600 Nm Dunlop 265/660 R 18 DTM B7 RS4 original (steel) Bosch ESP8 optimized Permanent recording of CAN bus during testing and races Up to 32 analog signals (e.g. temperature) can be recorded

5 References of succeeded development topics: - Optimisation of engine compartment streaming and cooling - Aerodynamic (details on: - Application of ABS controller depending on accurate race tire data. - Optimisation of brake balance between front and rear axle for optimized temperature distribution.

6 ABS Performance before modification

7 adhesion / traction Comparison of µ-slip characteristics on drum (d=2,547m) Dunlop 265 / 660 R 18 DTM spec Road tire 245 / 40 R 18 slip

8 ABS Performance after modification

9 Brake balance and temperature distribution

10 Results of ABS and brake distribution modification: - Brake balance between front and rear axle is adapted - Temperature distribution between front and rear axle has been optimized - Hydraulik pressure hysteresis during ABS operation has been limited (highly important for durability) - Due to the changes of ABS parameter setting in addition with modified brake pads from PAGID we reached the durability target of > 3000Km under racing condition. - During 24h race 2011 at Nürburgring no change of brake components has been necessary

11 Suspension tuning Particularities of track and race conditions Kinematic development Spring / Damper tuning

12 Particularities of track and race conditions Length - 25,378km Turns 86 (73 only on Nordschleife) Max Slope 17%

13 Particularities of track and race conditions

14 Particularities of track and race conditions TRACK very high slopes high speed compressions (e.g. Fuchsröhre) High speed crests (e.g. Pflanzgarten 1 + 2) High compression and banking (e.g. Karussell) changing track surfaces all over the track, varying from year to year

15 Particularities of track and race conditions Wheel travel on regular race track Wheel travel Rebound - 18 mm Bunp 30 mm

16 Particularities of track and race conditions Wheel travel on regular race track Wheel travel Rebound - 25 mm Bump - 43 mm

17 Particularities of track and race conditions Wheel travel on Nordschleife - Test Wheel travel Audi A3, 2007

18 Particularities of track and race conditions Vertical wheel speed on regular race track 500 mm/s 550 mm/s

19 Particularities of track and race conditions Vertical wheel speed on Nordschleife 550 mm/s 900 mm/s

20 Particularities of track and race conditions Large amounts of whee travel needed Kinematik over large wheel travels High vertical wheel speed (bump over 60% higher) Good sizing of the damper due to high speeds Temperature is affecting significantly damper performance Conducting air stream in vecinity of damper

21 Particularities of track and race conditions over 200 cars on 25 km Race large variety of classes and race driver Large difference in terms of lap time Fastest lap :27, :18 Fastest lap of slowest car 11:44, :02 Changing climatic conditions Enormous change of track conditions due to high amount of accidents No chance of clean lap if outside Top 30 (ideal line)

22 100,00 90,00 80,00 70,00 60,00 50,00 40,00 30,00 20,00 10, ,00 20,00 30,00 40,00 50,00 60,00 70,00 80,00 90,00 100,00 Kinematik development - Knew that suspension is working well in STW, STCC, Superstars - Decision to stick with (harder) elastic bushings - ADAMS-simulation - Experience of vehicle dynamics colleagues working on series car - change of bump steer as extremely dominant Redesign of upper control arms to get more static camber 140,00 120,00 100,00 80,00 60,00 40,00 20,00 0,00-20,00-40,00-60,00-80,00-100,00-120,00-140,00 rechts links Changed hight of steering rack for optimized bump-steer

23 Spring / damper tuning - Target heave frequency set to around 10% lower than on classic racetrack - Matlab / Simulink model for heave / pitch - As non aero-car, min. contact patch load variation most important criteria to look for - 4-post rig KW Automotive - Confirmed spring setting (260 N/mm N/mm) - Fine tuned damper curve - Having already done some aero-development, pitch frequencies also

24 Spring / damper tuning

25 Spring / damper tuning

26 Spring / damper tuning

27 Thank you very much for your attention ULS Stolberg