An Introduction To Race Car Engineering
An Introduction To Race Car Engineering
An Introduction To Race Car Engineering
Table of Contents
Page
Chapter 1 Some Basic Truths ......................................................................... 1/1 to 1/4
Basic concepts and truths leading to the successful study and understanding of
vehicle dynamics
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The Bottom Line it all begins and ends at the four contact patches ................................ 3/1
Yaw The First Look ........................................................................................................ 3/2
o Action and Reaction Forces ................................................................................. 3/2
o Rate of Load Transfer .......................................................................................... 3/4
o Lateral Acceleration versus Yaw ......................................................................... 3/5
o Definitions ........................................................................................................... 3/5
Race Tire Parameters ......................................................................................................... 3/6
o Slope .................................................................................................................... 3/6
o Vertical versus Normal Load ............................................................................... 3/8
o Decreasing Coefficient......................................................................................... 3/8
Slip and Regrip................................................................................................................... 3/9
o Trailing Edge Slip................................................................................................ 3/9
o Contact Patch Slip................................................................................................ 3/10
o Regrip .................................................................................................................. 3/10
o Longitudinal Forces ............................................................................................. 3/10
Longitudinal Shear Inline Braking and Acceleration ...................................................... 3/11
o Tread .................................................................................................................... 3/11
o Shear Ratio........................................................................................................... 3/11
o Longitudinal Slip ................................................................................................. 3/11
o Spring Buffer ....................................................................................................... 3/12
o Vertical Load on the Sidewall Cords ................................................................... 3/12
Camber Forces ................................................................................................................... 3/14
o Two Camber Components ................................................................................... 3/14
o Non-Vertical Resultant Elastic Forces ................................................................. 3/14
o Counteracting Centrifugal Forces ........................................................................ 3/115
o The Inner Workings of Camber ........................................................................... 3/15
o Camber and Surface Irregularities ....................................................................... 3/17
Aligning Moments Caster Torque and Pneumatic Trail.................................................. 3/17
o The Contact Patch Lateral Acceleration ........................................................... 3/17
o Caster Torque (Moment)...................................................................................... 3/19
o Pneumatic Torque (Tread Moment)..................................................................... 3/19
Further Definitions ............................................................................................................. 3/20
o Pneumatic Torque Carcass (Sidewall and Belt)................................................ 3/20
o Combined Pneumatic Aligning Torque ............................................................... 3/20
o Camber Aligning Forces ...................................................................................... 3/20
o Tire Pressure and Aligning Forces....................................................................... 3/20
o Vertical Load and Pneumatic Aligning Forces .................................................... 3/20
o Aligning Torque and Its Effect on the Steering Wheel ........................................ 3/20
o Tire Heating ......................................................................................................... 3/20
Energy Loss........................................................................................................................ 3/21
o Tread Momentum Loss Tire Drag and Tire Rolling Resistance ....................... 3/21
o Rolling Resistance Factors................................................................................... 3/21
o Rolling Resistance Coefficient............................................................................. 3/22
o Simulation Formulas............................................................................................ 3/22
o On Track Testing ................................................................................................. 3/23
o Shear Drag and Energy Loss................................................................................ 3/24
o Shear HP Loss...................................................................................................... 3/27
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This 67 page chapter presents and thoroughly explains all of the equations and algorithms used to
develop the Wan31 vehicle dynamics software. It does so in a carefully design sequential order
that will allow the user to not only understand the basics of dynamic simulation but also lays the
groundwork for the user to begin expanding the software to fit his/her unique software needs.