chassis: explainer

This is the content of the S2U chassis file for Lexus LFA. It provides some insight into what particular entries do in terms of car setup. Some data is incomplete and some is obsolete, but that's the best we've got.

Lexus LFA high-detail Car parameter file

[GENERAL]

TuningTier=3

Rules=0 // what rules to apply to garage setups (0=none, 1=stock car)

GarageDisplayFlags=7 // how settings are displayed in garage (add): 1=rear wing, 2=radiator, 4=more gear info

FeelerFlags=0 // how collision feelers are generated (add): 1=box influence 2=reduce wall-jumping 4=allow adjustment hack 8=top directions

Mass=1520.0 // all mass except fuel (1395kg car + 80kg driver weight)

Inertia=(2000.0,2180.0,400.0) // all inertia except fuel

FuelTankPos=(0.0, 0.200, 0.250) // location of tank affects center of gravity (very close and even slightly ahead of CG in F1)

FuelTankMotion=(560.0,0.7) // simple model of fuel movement in tank (spring rate per kg, critical damping ratio) Notes="" Symmetric=1

CGHeight=0.280 // height of body mass (excluding fuel) above reference plane

CGRightRange=(0.50, 0.000, 0) // fraction of weight on left tires

CGRightSetting=0

CGRearRange=(0.50, 0.005, 0)

CGRearSetting=0

GraphicalOffset=(0.0, 0.0, 0.0) // does not affect physics!

CollisionOffset=(0.0, 0.02, 0.0) // Moves collision mesh independently of G'offset

Undertray00=(0.90, 0.02, -1.895) // offset from center of car, and between axles// LF (Left front corner of splitter) (forward is negative, right is negative)

Undertray01=(-0.90, 0.02, -1.895) // offset from center of car, and between axles// RF (Right front corner of splitter)

Undertray02=(0.90, 0.02, 0.800) // offset from center of car, and between axles // LR (Left rear corner of rocker)

Undertray03=(-0.90, 0.02, 0.800) // offset from center of car, and between axles // RR (Right rear corner of rocker)

UndertrayParams=(262500.0,11600.0, 0.0) // undertray spring rate, damper rate, and coefficient of friction(770000.0,35000.0, 4.0)

FrontTireCompoundSetting=0 // Front compound index within brand

RearTireCompoundSetting=0 // Rear compound index within brand

FuelRange=(1.0, 1.0, 100)

FuelSetting=49

NumPitstopsRange=(0, 1, 4)

NumPitstopsSetting=3

Pitstop1Range=(1.0, 1.0, 100)

Pitstop1Setting=64

Pitstop2Range=(1.0, 1.0, 100)

Pitstop2Setting=64

Pitstop3Range=(1.0, 1.0, 100)

Pitstop3Setting=64

AIMinPassesPerTick=2 // minimum passes per tick (can use more accurate spring/damper/torque values, but takes more CPU)

AIRotationThreshold=0.12 // rotation threshold (rads/sec) to temporarily increment passes per tick

AIEvenSuspension=0.0 // averages out spring and damper rates to improve stability (0.0 - 1.0)

AISpringRate=1.0 // spring rate adjustment for AI physics (improves stability)

AIDamperSlow=0.5 // contribution of average slow damper into simple AI damper

AIDamperFast=0.5 // contribution of average fast damper into simple AI damper

AIDownforceZArm=0.150 // hard-coded center-of-pressure offset from vehicle CG

AIDownforceBias=0.0 // bias between setup and hard-coded value (0.0-1.0)

AITorqueStab=(1.25, 1.25, 1.25) // torque adjustment to keep AI stable

[FRONTWING]

FWRange=(0.0, 1.0, 0) // front wing range

FWSetting=0 // front wing setting

FWMaxHeight=(0.10) // maximum height to take account of for downforce

FWDragParams=(0.04, 0.003, 0.00) // base drag and 1st and 2nd order with setting

FWLiftParams=(-0.270, -0.028, 0.00) // base lift and 1st and 2nd order with setting

FWLiftHeight=(0.335) // effect of current height on lift coefficient

FWLiftSideways=(0.0) // dropoff in downforce with yaw (0.0 = none, 1.0 = max)

FWLeft=(-0.30, 0.0, 0.0) // aero forces from moving left

FWRight=(0.30, 0.0, 0.0) // aero forces from moving right

FWUp=(0.0, -0.5, -0.001) // aero forces from moving up

FWDown=(0.0, 0.25, 0.001) // aero forces from moving down

FWAft=(0.0, 0.02, -0.02) // aero forces from moving rearwards

FWFore=(0.0, 0.0, 0.0) // aero forces from moving forwards (recomputed from settings)

FWRot=(0.05, 0.025, 0.075) // aero torque from rotating

FWCenter=(0.00, 0.00, -0.60) // center of front wing forces (offset from center of front axle in ref plane)

[REARWING]

RWRange=(0.0, 1.0, 0) // rear wing range

RWSetting=0 // rear wing setting

RWDragParams=(0.04, 0.003, 0.00) // base drag and 1st and 2nd order with setting

RWLiftParams=(-0.350, -0.028, 0.00) // base lift and 1st and 2nd order with setting

RWLiftSideways=(0.0) // dropoff in downforce with yaw (0.0 = none, 1.0 = max)

RWPeakYaw=(0.0, 0.00) // angle of peak, multiplier at peak

RWLeft=(-0.7, 0.0, 0.0) // aero forces from moving left

RWRight=(0.7, 0.0, 0.0) // aero forces from moving right

RWUp=(0.0, -0.50, -0.002) // aero forces from moving up

RWDown=(0.0, 0.25, 0.002) // aero forces from moving down

RWAft=(0.0, 0.03, -0.4) // aero forces from moving rearwards

RWFore=(0.0, 0.0, 0.0) // aero forces from moving forwards (recomputed from settings)

RWRot=(0.08, 0.05, 0.11) // aero torque from rotating

RWCenter=(0.00, 0.60, 0.80) // center of rear wing forces (offset from center of rear axle at ref plane)

[BODYAERO]

BodyDragBase=(0.260) // base drag

BodyDragHeightAvg=(0.22) // drag increase with average ride height

BodyDragHeightDiff=(0.47) // drag increase with front/rear ride height difference

BodyMaxHeight=(0.20) // maximum ride height that affects drag/lift

BodyLeft=(-0.6, 0.0, 0.0) // aero forces from moving left

BodyRight=(0.6, 0.0, 0.0) // aero forces from moving right

BodyUp=(0.0, -1.0, 0.0) // aero forces from moving up

BodyDown=(0.0, 1.0, 0.0) // aero forces from moving down

BodyAft=(0.0, 0.20, -0.8) // aero forces from moving rearwards

BodyFore=(0.0, -0.0412, 0.435) // aero forces from moving forwards (lift value important!)

BodyRot=(4.73, 4.3, 1.87) // aero torque from rotating

BodyCenter=(0.0, 0.50, -1.55) // center of body aero forces (offset from center of rear axle at ref plane)

RadiatorRange=(0.0, 1.0, 4) // radiator range

RadiatorSetting=3 // radiator setting

RadiatorDrag=(0.005) // effect of radiator setting on drag

RadiatorLift=(0.003) // effect of radiator setting on lift

BrakeDuctRange=(0.0, 1.0, 5) // brake duct range

BrakeDuctSetting=1 // brake duct setting

BrakeDuctDrag=(0.006) // effect of brake duct setting on drag

BrakeDuctLift=(0.00825) // effect of brake duct setting on lift

[DIFFUSER]

DiffuserBase=(-0.000, -0.50, 5.0) // base lift and 1st/2nd order with rear ride height

DiffuserFrontHeight=(0.000) // 1st order with front ride height

DiffuserRake=(0.005, -0.0, 0.0) // Optimum rake (rear - front ride height), 1st order with current difference from opt, 2nd order

DiffuserLimits=(0.010, 0.100, 0.055) // Min ride height before stalling begins (0.0 to disable), max rear ride height for computations, max rake difference for computations

DiffuserStall=(0.0, 1.0) // function to compute stall ride height (0.0=minimum, 1.0=average), downforce lost when bottoming out (0.0=none,1.0=complete stall)

DiffuserSideways=(0.0) // dropoff with yaw (0.0 = none, 1.0 = max)

DiffuserCenter=(0.0, 0.00, -1.30) // center of diffuser forces (offset from center of rear axle at ref plane)

[SUSPENSION]

ApplySlowToFastDampers=0 // whether to apply slow damper settings to fast damper settings

CorrectedInnerSuspHeight=-1 // instead of moving inner susp height relative with ride height, use this offset (set to -1 for original behavior)

AdjustSuspRates=1 // adjust suspension rates due to motion ratio ( 0=enable, 1=disable)

AlignWheels=1 // correct for minor graphical offsets

SpringBasedAntiSway=1 // 0=diameter-based, 1=spring-based

FrontAntiSwayBase=0.0

FrontAntiSwayRange=(10000.0, 10000.0, 8)

FrontAntiSwaySetting=4

FrontAntiSwayRate=(1.36e11, 4.0) // not applicable with spring-based antisway

AllowNoAntiSway=1 // Whether first setting gets overridden to mean no antisway bar

RearAntiSwayBase=0.0

RearAntiSwayRange=(5000.0, 5000.0, 8)

RearAntiSwaySetting=1

RearAntiSwayRate=(1.36e11, 4.0) // not applicable with spring-based antisway

FrontToeInRange=(2.0, -0.1, 41)

FrontToeInSetting=20

RearToeInRange=(2.0, -0.1, 41)

RearToeInSetting=19

LeftCasterRange=(0.0, 0.1, 100) // front-left caster

LeftCastersetting=20

RightCasterRange=(0.0, 0.1, 100) // front-right caster

RightCastersetting=20

[CONTROLS]

ThrottleControl=(2,2,1,1)

AntilockBrakes=(2,2,1,1)

SteeringFFBMult=1.0

UpshiftAlgorithm=(0.97,0.0) // percentage of the rev limit to upshift at. If the 2nd value is non-zero, then we will use it as the exact RPM to upshift at.

DownshiftAlgorithm=(0.85,0.80,0.80) // percentage of "optimum" downshift point in high gears, percentage of "optimum" downshift point in low gears, oval adjustment.

SteerLockRange=(0.0, 1.0, 42)

SteerLockSetting=22

RearBrakeRange=(0.00, 0.01, 100)

RearBrakeSetting=50

BrakePressureRange=(0.80, 0.01, 20)

BrakePressureSetting=10

HandbrakePressRange=(0.00, 0.05, 21) //

HandbrakePressSetting=20

AutoUpshiftGripThresh=0.0 // auto upshift waits until all driven wheels have this much grip (reasonable range: 0.4-0.9)

AutoDownshiftGripThresh=0.0 // auto downshift waits until all driven wheels have this much grip (reasonable range: 0.4-0.9)

TractionControlGrip=(1.00, 0.20) // average driven wheel grip multiplied by 1st number, then added to 2nd

TractionControlLevel=(0.30, 0.90) // effect of grip on throttle for low TC and high TC

ABS4Wheel=1 // 0 = old-style single brake pulse, 1 = more effective 4-wheel ABS

ABSGrip=(1.00, 0.20) // grip multiplied by 1st number and added to 2nd

ABSLevel=(0.20, 0.40) // effect of grip on brakes for low ABS and high ABS

[ENGINE]

SpeedLimiter=1 // Whether a pitlane speed limiter is available

[DRIVELINE]

AdjustableFinalGearsMinimumLevel=0

AdjustableGearsMinimumLevel=0

AdjustableGearsRange=2

AdjustableGearsFinalRange=4

ClutchEngageRate=0.8 //Auto clutch gradual engagement rate from neutral to 1st gear.

ClutchInertia=0.0148

ClutchTorque=700.0

ClutchWear=0.0

ClutchFriction=15.000

BaulkTorque=750.0

SemiAutomatic=0 // whether throttle and clutch are operated automatically

UpshiftDelay=0.10 // delay in selecting higher gear (low for semi-automatic, higher for manual)

UpshiftClutchTime=0.10 // time to ease auto-clutch in AFTER upshift (0.0 for F1 cars)

DownshiftDelay=0.40 // delay in selecting lower gear (low for semi-automatic, higher for manual)

DownshiftClutchTime=0.50 // time to ease auto-clutch in AFTER downshift (used to be SemiAutoClutchTime, note that the shift will complete significantly before the clutch is fully engaged)

DownshiftBlipThrottle=0.70 // amount of throttle used to blip if controlled by game (instead of player)

WheelDrive=REAR // which wheels are driven: REAR, FOUR (even torque split), or FRONT

FinalDriveSetting=28 // indexed into GearFile list

ReverseSetting=0

ForwardGears=6

Gear1Setting=1

Gear2Setting=21

Gear3Setting=38

Gear4Setting=50

Gear5Setting=57

Gear6Setting=59

DiffPumpTorque=00.0 // at 100% pump diff setting, the torque redirected per wheelspeed difference in radians/sec (roughly 1.2kph)

DiffPumpRange=(0.00, 0.00, 0)

DiffPumpSetting=0

DiffPowerRange=(0.0,0.05,20) // fraction of power-side input torque transferred through diff

DiffPowerSetting=7 // (not implemented for four-wheel drive)

DiffCoastRange=(0.0,0.05,20) // fraction of coast-side input torque transferred through diff

DiffCoastSetting=7 // (not implemented for four-wheel drive)

DiffPreloadRange=(0.0, 10.0, 20) // preload torque that must be overcome to have wheelspeed difference

DiffPreloadSetting=8 // (not implemented for four-wheel drive)

[FRONTLEFT]

BumpTravel=-0.000 // travel to bumpstop with zero packers and zero ride height

ReboundTravel=-0.160 // these two numbers assume front ride height is 30cm to 90cm with 10cm leeway

BumpStopSpring=60000.0 // initial spring rate of bumpstop

BumpStopRisingSpring=1.25e9 // rising spring rate of bumpstop (multiplied by deflection squared)

BumpStopDamper=2500.0 // initial damping rate of bumpstop

BumpStopRisingDamper=2.19e7 // rising damper rate of bumpstop (multiplied by deflection squared)

BumpStage2=0.090 // speed where damper bump moves from slow to fast

ReboundStage2=-0.090 // speed where damper rebound moves from slow to fast

FrictionTorque=9.50 // Newton-meters of friction between spindle and wheel

SpinInertia=1.622 // inertia in pitch direction including any axle

CGOffsetX=0.000 // x-offset from graphical center to physical center (NOT IMPLEMENTED)

PushrodSpindle=(-0.150, -0.150, 0.000) // relative to spindle

PushrodBody=(-0.350, 0.320, 0.000) // spring/damper connection to body (relative to wheel center)

CamberRange=(-5.0, 0.1, 100)

CamberSetting=35

PressureRange=(0.0, 1.0, 286)

PressureSetting=230

PackerRange=(0.000, 0.001, 30)

PackerSetting=0

SpringMult=1.0 // take into account suspension motion if spring is not attached to spindle (affects physics but not garage display)

SpringRange=(65000.0, 5416.0, 6)

SpringSetting=0

RideHeightRange=(0.110, -0.0045, 10)

RideHeightSetting=0

DamperMult=1.00 // take into account suspension motion if damper is not attached to spindle (affects physics but not garage display)

SlowBumpRange=(4000.0, 300.0, 11)

SlowBumpSetting=0

FastBumpRange=(2000.0, 200.0, 11)

FastBumpSetting=0

SlowReboundRange=(8000.0, 300.0, 16)

SlowReboundSetting=0

FastReboundRange=(4000.0, 300.0, 16)

FastReboundSetting=0

BrakeDiscRange=(0.035, 0.000, 0) // disc thickness

BrakeDiscSetting=0

BrakePadRange=(0, 1, 5) // pad type (not implemented)

BrakePadSetting=2

BrakeDiscInertia=0.001 // inertia per meter of thickness

BrakeOptimumTemp=450.0 // optimum brake temperature in Celsius

BrakeFadeRange=450.0 // temperature outside of optimum that brake grip drops to half (too hot or too cold)

BrakeWearRate=1.215e-011 // meters of wear per second at optimum temperature

BrakeFailure=(1.33e-002,7.20e-004) // average and variation in disc thickness at failure

BrakeTorque=4500.0 // maximum brake torque at zero wear and optimum temp

BrakeHeating=0.00050 // heat added linearly with brake torque

BrakeCooling=(1.910e-002,0.667e-004) // minimum brake cooling rate (static and per unit velocity)

BrakeDuctCooling=2.000e-004 // brake cooling rate per brake duct setting

[FRONTRIGHT]