Champcaratlantic Contract Tyre Data

ChampcarAtlantic Contract Tyre Data

V2.0

Introduction

General Data

Scrubbing-In

Orientation

Stability Rig Schematic

Delft Pacejka 96 Lateral Force (pure) Equation Set

Delft Pacejka ’96 Model

Introduction

Please find the ‘Stab Rig’ data, Pacejka ’96 Model, static and dynamic spring rate data as well as general information regarding the Champcar Atlantic contract tyre.

This document should be read in conjunction with 3 other files:-

Stab front.xls The stabrig response for the front tyre.

Stab rear.xls The stabrig response for the rear tyre.

Spring.xls Static and dynamic (rolling) spring rate data.

If there are any questions arising from this data or indeed any other aspect of the Champcar Atlantic tyre, please do not hesitate to give me a call (GMT:- New York + 5hours) or post / email at the following address:-

Pete Morgan, Technical Engineer.

Cooper-Avon Tyres Racing Division.

Tel:- +44 (0)1225 35 7735.

Fax:- +44 (0)1225 707 443

Email:-

General Data

Slick / Wet
Front / Rear / Front / Rear
Size / 240/600R15 / 330/620R15 / 240/600R15 / 330/620R15
Spec Number / 13083S / 13090S / 13104M / 13163M
Rim Size / 10J x 15 / 14J x 15 / 10J x 15 / 14J x 15
Overall Diameter (mm -1) / 596 / 620 / 596 / 619
Tread Width (mm-1) / 246 / 352 / 246 / 352
Section Width (mm -1) / 278 / 388 / 278 / 388
Overall Diameter (inches -1) / 23.46 / 24.41 / 23.46 / 24.37
Tread Width (inches -1) / 9.69 / 13.86 / 9.69 / 13.86
Section Width (inches -1) / 10.94 / 15.28 / 10.94 / 15.28
Suggested Pressure Slick (hot) / 20-23psi / 18-21psi / N/A / N/A
Suggested Pressure Wet (cold) / N/A / N/A / 16-19psi / 15-18psi

Please note that the metal valve caps supplied are to be used at all times to avoid potentially dangerous unintentional pressure loss.

Scrubbing-In

Cooper Tires would like to point out that the use of new (unscrubbed) tyres in a race will increase the running temperature ofthosetyres over and above what would normally be expected from a tyre that has been scrubbed in by the usual means. Whilst this has no history of causing any issues to date, there is always the chance that where there is a higher ambient temperature, and /or conditions likely to load the tyre more than seen previously such asa highly abrasivesurface, very high speed chicanes etc., the possibility of a heat related failure is increased. Moreover, any advantage from running new tyres that would normally be experienced in cooler climates will certainly be lost.

To that end, we recommend that all race tyres be at least lightly scrubbed prior to use where possible.

Orientation

In order to respect the tread joint that is inevitable in the manufacture of racing tyres, tyres should be fitted such that the orientation of the predominant forces do not work to open the joint or ‘splice’. The service crew will fit all tyres in sets and they mark up the tyres with their direction of orientation. There will be a spec number and a barcode on only ONE sidewall of each tyre. If for any reason the markings are removed, use the following guide to establish the correct direction of rotation:-

Stability Rig Schematic

A schematic diagram of the Stability rig used to generate the cornering force against slip angle, and self aligning torque against slip angle graphs.

For the purposes of the Pacejka Model creation, all values from the original stabrig data were converted to Newtons. All angular measurements are in degrees (°). A positive vertical force was considered to be downwards. A positive slip angle was considered to be as if the tyre was turning left. The Pacejka model is for pure lateral load, no longitudinal forces are included. As a result, the full model has many zeros in it.

Delft Pacejka 96 Lateral Force (pure) Equation Set

Fy:(N),a,g:(rad),Fz:(N)

Fy = Fy0(a,g,Fz)

Fy0 = Dysin[Cytan-1{Byay-Ey(Byay-tan-1(Byay))}]+SVy

ay = (a+SHy)

gy = glgy

Cy = pCy1lCy

Dy = myFz

my = (pDy1+pDy2dfz)(1-pDy3gy2)lmy

Ey = (pEy1+pEy2dfz){1-(pEy3+pEy4gy)sgn(ay)}lEy

Ky = pKy1Fz0sin[2tan-1{Fz/(pKy2Fz0lFz0)}](1-pKy3|gy|)lFz0lKy

By = Ky/(CyDy)

SHy = (pHy1+pHy2dfz+pHy3gy)lHy

SVy = Fz{pVy1+pVy2dfz+(pVy3+pVy4dfz)gy}lVylmy

Parameters
pCy1 / shape factor C
pDy1,pDy2,pDy3 / peak factor D
pEy1,pEy2,pEy3,pEy4 / curvature factor E
pKy1,pKy2,pKy3 / slip stiffness BCD
pHy1,pHy2,pHy3 / horizontal shift H
pVy1,pVy2,pVy3,pVy4 / vertical shift V
Fz0 / nominal load
Scaling factors
lFz0 / nominal load
lmy / peak friction coefficient
lKy / slip stiffness
lCy / shape factor
lEy / curvature factor
lHy / horizontal shift
lVy / vertical shift
lgy / camber force stiffness
Descriptions
pCy1 / Shape factor Cy for lateral forces
pDy1 / Lateral friction y
pDy2 / Variation of friction y with load
pDy3 / Variation of friction y with camber2
pEy1 / Lateral curvature Ey at Fz0
pEy2 / Variation of curvature Ey with load
pEy3 / Zero order camber dependency of curvature Ey
pEy4 / Variation of curvature Ey with camber
pKy1 / Maximum value of stiffness Ky/Fz0
pKY2 / Load at which Ky reaches maximum value
pKy3 / Variation of Ky/Fz0 with camber
pHy1 / Horizontal shift SHy at Fz0
pHy2 / Variation of shift SHy with load
pHy3 / Horizontal shift SHy with camber
pVy1 / Vertical shift in SVy/Fz at Fz0
pVy2 / Variation of shift SVy/Fz with load
pVy3 / Variation of shift SVy/Fz with camber
pVy4 / Variation of shift SVy/Fz with camber and load

CONFIDENTIAL, PROPRIETARY AND / OR TRADE SECRET INFORMATION.
The information contained in this document is intended only for the use of the individual to whom it was sent and may contain confidential, proprietary and / or trade secret information that is the property of Cooper Tire and Rubber Company and / or Cooper-Avon Tyres Limited. If the reader of this document is not the intended recipient, you are hereby notified that you should not read any further, and any dissemination, distribution or copying of this communication is strictly prohibited. Copyright © Unpublished.

DelftPacejka ’96 Model

Slick Front / Slick Rear
[VERTICAL]
FNOMIN = / 3698.888 / 5599.036
[ALIGNING COEFFICIENTS]
QBZ1 = / 0 / 0
QBZ2 = / 0 / 0
QBZ3 = / 0 / 0
QBZ4 = / 0 / 0
QBZ5 = / 0 / 0
QBZ9 = / 0 / 0
QCZ1 = / 0 / 0
QDZ1 = / 0 / 0
QDZ2 = / 0 / 0
QDZ3 = / 0 / 0
QDZ4 = / 0 / 0
QDZ6 = / 0 / 0
QDZ7 = / 0 / 0
QDZ8 = / 0 / 0
QDZ9 = / 0 / 0
QEZ1 = / 0 / 0
QEZ2 = / 0 / 0
QEZ3 = / 0 / 0
QEZ4 = / 0 / 0
QEZ5 = / 0 / 0
QHZ1 = / 0 / 0
QHZ2 = / 0 / 0
QHZ3 = / 0 / 0
QHZ4 = / 0 / 0
[LATERAL COEFFICIENTS]
PCY1 = / 0.716892 / 0.330366
PDY1 = / -1.87589 / -3.44515
PDY2 = / 0.405923 / 1.198582
PDY3 = / -3.09845 / -5.12527
PEY1 = / -0.33934 / -0.15461
PEY2 = / 0.86864 / 0.17771
PEY3 = / -0.24803 / -0.25747
PEY4 = / -12.70670 / -10.53810
PKY1 = / -29.30100 / -27.32930
PKY2 = / 1.69975 / 1.17825
PKY3 = / 0.48883 / 0.08650
PHY1 = / 0.00929 / 0.00793
PHY2 = / -0.00069 / -0.00047
PHY3 = / 0.06210 / 0.07830
PVY1 = / 0.03510 / 0.01850
PVY2 = / -0.05260 / -0.11944
PVY3 = / -0.16053 / -0.13668
PVY4 = / -0.43314 / -0.51425
[LONGITUDINAL COEFFICIENTS]
PCX1 = / 0 / 0
PDX1 = / 0 / 0
PDX2 = / 0 / 0
PEX1 = / 0 / 0
PEX2 = / 0 / 0
PEX3 = / 0 / 0
PEX4 = / 0 / 0
PKX1 = / 0 / 0
PKX2 = / 0 / 0
PKX3 = / 0 / 0
PHX1 = / 0 / 0
PHX2 = / 0 / 0
PVX1 = / 0 / 0
PVX2 = / 0 / 0
[DATA]
CAMBER = / 0 / 0