Post on 21-Feb-2021
transcript
Dipl.-Ing. Andrei Filep, November 15th 2012
Suspension setup for the Nürburgring Nordschleife –
differences to regular race tracks
Content:
- Team Tuning Akademie / development topics
- Technology platform Audi A4 quattro
- References
- Suspension tuning
- Summary
Development and verification of chassis
control systems
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
Alternative fuel and efficiency concepts
Improvement of Brake and suspension items for
special requirements
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
Races Testing of innovative technologies under racing conditions Representation of new technologies and project partners in public view
Members of Tuning Akademie are:
- Engineers and technicians of technical development
department of Audi AG and ika (RWTH Aachen)
Technology platform Audi A4 3.0 TDI quattro
• body: Audi RS4 (B7)
• engine: V6 TDI (Generation 1)
• capacity: 2967ccm
• power: 230 kW
• torque: 600 Nm
• tires: Dunlop 265/660 R 18 DTM
• brakes: B7 RS4 original (steel)
• ABS / ESP: Bosch ESP8 optimized
• Permanent recording of CAN bus during testing and races
• Up to 32 analog signals (e.g. temperature) can be recorded
Technical data
References of succeeded development topics:
- Optimisation of engine compartment streaming and cooling
- Aerodynamic (details on: www.tuning-akademie.de\downloads)
- Application of ABS controller depending on accurate race tire data.
- Optimisation of brake balance between front and rear axle for
optimized temperature distribution.
ABS Performance before modification
Dunlop 265 / 660 R 18 DTM spec
Road tire 245 / 40 R 18
Comparison of µ-slip characteristics on drum (d=2,547m)
slip
adhesio
n / t
raction
ABS Performance after modification
Brake balance and temperature distribution
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
Suspension tuning
• Particularities of track and race conditions • Kinematic development • Spring / Damper tuning
Particularities of track and race conditions
Length - 25,378km Turns – 86 (73 only on Nordschleife) Max Slope – 17%
Particularities of track and race conditions
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
Particularities of track and race conditions
Rebound - 18 mm Bunp – 30 mm
Wheel travel
Wheel travel on regular race track
Particularities of track and race conditions
Wheel travel
Rebound - 25 mm Bump - 43 mm
Wheel travel on regular race track
Particularities of track and race conditions
Wheel travel
Audi A3, 2007
Wheel travel on Nordschleife - Test
Particularities of track and race conditions
500 mm/s 550 mm/s
Vertical wheel speed on regular race track
Particularities of track and race conditions
550 mm/s 900 mm/s
Vertical wheel speed on Nordschleife
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
Particularities of track and race conditions
Race
• over 200 cars on 25 km • large variety of classes and race driver • Large difference in terms of lap time
• Fastest lap 2012 – 8:27,161 2002 – 9:18 • Fastest lap of slowest car – 11:44,602 2002 – 13:02
• 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)
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
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links
Changed hight of steering rack for optimized bump-steer
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 tuning @ KW Automotive - Confirmed spring setting (260 N/mm - 320 N/mm)
- Fine tuned damper curve - Having already done some aero-development,
looked @ pitch frequencies also
Spring / damper tuning
Spring / damper tuning
Spring / damper tuning
ULS Stolberg
www.tuning-akademie.de
www.d-t-gmbh.de
www.rowe-mineraloel.com www.kw-automotive.de
www.fkfs.de www.evonik.de
www.cradle.co.jp
www.hjs.com www.bn-pipes.de
www.eibach.de www.bosch.de www.stahlwille.de
www.fantasyjunction.com www.conti-online.de
www.krontec.de
www.ikv.rwth-aachen.de
www.iqs-cargo.de
Thank you very much for your attention