iRacing 718 Cayman GT4 Porsche Owner’s Manual

**iRacing 718 Cayman GT4 Porsche Owner’s Manual

**

Dear racing User

Congratulations on your purchase of the Porsche 718 Cayman GT4! From all of us at racing, we appreciate your support and your commitment to our product. We aim to deliver the ultimate sim racing experience, and we hope that you’ll find plenty of excitement with us behind the wheel of your new car

Few automotive manufacturers are as revered as Porsche, and many drivers will take any opportunity they can get to climb behind the wheel of one of the brand’s iconic vehicles. Enter the 718 Cayman GT4 Clubs port, whimsiness 425 horsepower of Porsche performance with the nimble, approachable GT4 platform.

The result is a highly popular sports car raced the world over, from single- class championships to the multiclass IMSA Michelin Pilot Challenge (where it makes its home on racing). Responsive in its handling and a whole lot of fun, it’s easy to see why the 718 Cayman GT4 Clubs port is also popular as a track day car

The following guide explains how to get the most out of your new car, from how to adjust its settings off of the track to what you’ll see inside of the cockpit while driving. We hope that you’ll find it useful in getting up to speed

Thanks again for your purchase, and we’ll see you on the track!

PORSCHE 718 CAYMAN GT4 | TECH SPECS

MID-ENGINE RWD WITH FRONT AND REAR MCPHERSON STRUT SUSPENSION

ALUMINUM 6 CYLINDER BOXER ENGINE

Introduction

The information found in this guide is intended to provide a deeper understanding of the chassis setu hutments available in the garage, so that you may use the garage to tune the chassis setup to your preference.

Before diving into chassis adjustments, though, it is best to become familiar with the car and track. To that end, we have provided baseline setups for each track commonly raced by these cars. To access the baseline tops, simply open the Garage, click racing Setups, and select the appropriate setup for your track of choice. If you are driving a track for which a dedicated baseline setup is not included, you may select a setup for a similar track to use as your baseline. After you have selected an appropriate setup, get on track and focus on making smooth and consistent laps, identifying the proper racing line and experiencing tire wear and handling trends over a number of laps.

Once you are confident that you are nearing your driving potential with the included baseline setups, read on to begin tuning the car to your handling preferences.

GETTING STARTED

Before starting the car, it is recommended to map controls for Brake Bias and ABS/TCS/ESC settings. While this is not mandatory, this will allow you to make quick changes to the brake bias and stability management systems to suit your driving while out on track.

Once you load into the car, getting started is as easy as pulling the “upshift” paddle to put it into gear, anting the accelerator pedal. This car uses an automated sequential transmission and does not require manual clutch operation to shift in either direction. However, the car’s downshift protection will not allow you to downshift if it feels you are traveling too fast for the gear requested. If that is the case, the downshift command will simply be ignored

Upshifting is recommended when the shift lights on the dashboard are all fully illuminated. This is at 7500 rpm.

LOADING AN iRACING SETUP

Upon loading into a session, the car will automatically load the racing Baseline setup [baseline. To]. If you would prefer one of racing’s pre-built setups that suit various conditions, you may load it by clicking Garage > ricing Setups > and then selecting the setup to suit your needs

If you would like to customize the setup, simply make the changes in the garage that you would like to update and click apply. If you would like to save your setup for future use click “Save As” on the right to name and save the changes

To access all of your personally saved setups, click “My Setups” on the right side of the garage.

If you would like to share a setup with another driver or everyone in a session, you can select “Share” on the right side of the garage to do so.

If a driver is trying to share a setup with you, you will find it under “Shared Setups” on the right side of three as well.

Dash Pages

DASH CONFIGURATION

Left Light stack top two LED’s :  Illuminates yellow as a pair to indicate a left front lockup
Left Light stack lower two LED’s : Illuminates purple as a pair to indicate left rear wheelspin
Right Light stack top two LED’s : Illuminates yellow as a pair to indicate a right front lockup
Right Light stack lower two LED’s : Illuminates purple as a pair to indicate right rear wheelspin
Row 1 Left :Indicates tire fitted in the real car, relevant for pit limiter and other calibrations
Row 1 Second from left :Indicates usage of the high beam headlights
Row 1 Center :Road speed (km/h or mph)
Row 1 Right : Current session lap number
Row 2 Left :Engine oil temperature (Celsius or Fahrenheit)
Row 2 Center Currently :selected gear
Row 2 Right: Last lap time as mm:ss:ms
Row 3 Left : Engine oil pressure (Bar or psi)
Row 3 Right :Delta to session best lap time as ss:ms
Row 4 Left : Engine water temperature (Celsius or Fahrenheit)
Row 5 Left :Remaining fuel (Litres or US Gallons)
Row 6 Lef t :Percentage change in brake bias relative to initial value including graphic depiction
Row 6 Cente r :Current tire pressures arranged in vehicle orientation (kPa or psi)
Row 7 Left: Indicates a fault in the real car when illuminated
Row 7 Second from lef t: Current ABS/TC/ESC setting
Row 7 Cente r :Current engine rpm
Row 7 Third from right : TC on/off indicator
Row 7 Second from righ t: ESC on/off indicator
Row 7 Right ” Current gearbox mode: M in normal operation, P in neutral and R in reverse

PIT LIMITER

When the pit limiter is active a large green box containing the current speed and gear will fill the upper portion of the dashboard. The box will turn orange if traveling above the pit road speed limit with the limiter active.

SHIFT LIGHTS

The shift lights illuminate from the outer edges inwardly. Illumination of the first LED will shift depending on
the selected gear as such, the below values are only valid for 3rd gear

1 Green: 6500 rpm
2 Green :6700 rpm
3 Green :6900 rpm
1 Yellow : 7100 rpm
2 Yellow :7200 rpm
3 Yellow :7300 rpm
1 Red :7400 rpm
All Flashing :7500 rpm

Advanced Setup Options

This section is aimed toward more advanced users who want to dive deeper into the different aspects of ticle’s setup. Making adjustments to the following parameters is not required and can lead to significant changes in the way a vehicle handles. It is recommended that any adjustments are made in an incremental fashion and only singular variables are adjusted before testing changes.

Tires

COLD AIR PRESSURE
Air pressure in the tire when the car is loaded into the world. Higher pressures will reduce rolling drag and heat buildup, but will decrease grip. Lower pressures will increase rolling drag and heat buildup, but Kilcrease grip. Higher speeds and loads require higher pressures, while lower speeds and loads will see bet performance from lower pressures. Cold pressures should be set to track characteristics for optimum performance Generally speaking, it is advisable to start at lower pressures and work your way upwards as required.

HOT AIR PRESSURE
Air pressure in the tire after the car has returned to the pits. The difference between cold and hot pressures can be used to identify how the car is progressing through a run in terms of balance, with heavier-loaded tire eking a larger difference between cold and hot pressures. Ideally, tires that are worked in a similar way should build pressure at the same rate to prevent a change in handling balance over the life of the tire, so cold presser hold be adjusted to ensure that similar tires are at similar pressures once up to operating temperature. Pressures should be analyzed once the tires have stabilized after a period of laps. As the number of laps per run will vary depending upon track length a good starting point is approximately 50% of a full fuel run

TIRE TEMPERATURES
Tire carcass temperatures, measured via Pyrometer, once the car has returned to the pits. Wheel Loads and the amount of work a tire is doing on-track are reflected in the tire’s temperature, and these values can be used to analyze the car’s handling balance. Center temperatures are useful for directly comparing the work done  ach tire, while the Inner and Outer temperatures are useful for analyzing the wheel alignment (predominantly camber) while on track. These values are measured in three zones across the tread of the tire. Inside, Middle and Outer

TREAD REMAINING
The amount of tread remaining on the tire once the car has returned to the pits. Tire wear is very helpful tidying any possible issues with alignment, such as one side of the tire wearing excessively, and can be used in conjunction with tire temperatures to analyze the car’s handling balance. These values are measured in the same zones as those of temperature.

Chassis

FRONT

ARB SETTING
Increasing the ARB setting shortens the ARB moment arm and will increase the roll stiffness of the front  suspension, resulting inless body roll but increasing mechanical understeer. This can in some cases, lead to a more responsive steering feel for the driver. Conversely, reducing the ARB setting lengthens the ARB moment arm, softening the suspension in roll and increasing body roll but decreasing mechanical understeer. This can result in a less- responsive feel from the steering, but grip across the front axle will increase. Along with this, the effects of softening or stiffening the ARB assembly in relation to aerodynamics should also be considered, a softer ARB configuration will result in more body roll which will decrease control of the aero platform in high speed corners and potentially lead to a loss in aero efficiency. Three ARB settings are available ranging from 1 ‘soft’ to 3 ‘stiff’

TOE-IN
Toe is the angle of the wheel, when viewed from above, relative to the centerline of the chassis. Toe-in is when the front of the wheel is closer to the centerline than the rear of the wheel, and Toe-out is the opposite. On the front end, adding toe-out will increase slip in the inside tire and decrease straight-line stability while adding toe-in will reduce the slip and increase straight-line stability.

CROSS WEIGHT
The percentage of total vehicle weight in the garage acting across the right front and left rear corners. 50.0% is generally optimal for non-oval tracks as this will produce symmetrical handling in both left and right ham rners providing all other chassis settings are symmetrical. Higher than 50% cross weight will result in mor understeer in left hand corners and increased oversteer in right hand corners, cross weight can be adjusted by making changes to the spring perch offsets at each corner of the car.

IN-CAR DIALS

BRAKE PRESSURE BIAS
Brake Bias is the percentage of braking force that is being sent to the front brakes. Values above 50% result in greater pressure in the front brake line relative to the rear brake line which will shift the brake balancforwards increasing the tendency to lock up the front tyres but potentially increasing overall stability in braking zones. This should be tuned for both driver preference and track conditions to get the optimum braking performance for a given situation.

BRAKE PADS
The vehicle’s braking performance can be altered via the Brake Pad Compound. The “Low” setting provides the least friction, reducing the effectiveness of the brakes but providing the most modulation, while “Medium” and “High” provide more frictionand increase the effectiveness of the brakes but the least modulation.

ABS/TC/ESC SETTING
This option provides a combined control for the traction control (TC) and ABS (Anti-Lock Braking System). Positions 1 to 11 offer increasing levels of TC and ABS intervention/sensitivity with 11 providing the mo. stance and 1 providing the least assistance. Position 0 disables both the TC and AB

LEFT/RIGHT FRONT

CORNER WEIGHT
The weight underneath each tire under static conditions in the garage. Correct weight arrangement around the car is crucial for optimizing a car for a given track and conditions. Individual wheel weight adjustments and crossweight adjustments are made via the spring perch offset adjustments at each corner.

FRONT RIDE HEIGHT
Distance from ground to a reference point on the chassis. Since these values are measured to a specific efference point on the car, these values may not necessarily reflect the vehicle’s ground clearance, but instead provide a reliable value for the height of the car off of the race track at static values. Adjusting Ride Heights is key for optimum performance, as they can directly influence the vehicle’s aerodynamic performance as well as mechanical grip. Increasing front ride height will decrease front downforce as well as decrease over downforce, but will allow for more weight transfer across the front axle when cornering. Conversely, reducing ride height will increase front and overall downforce, but reduce the weight transfer across the front axle. Minimum legal front ride height is 96.0 mm.

SPRING PERCH OFFSET
Used to adjust the ride height at this corner of the car by changing the installed position of the spring creasing the spring perch offset will result in lowering this corner of the car while reducing the spring perch offset will raise this corner of the car. These changes should be kept symmetrical across the axle (left to right) to ensure the same corner ride heights and no change in cross weight. The spring perch offsets can also be used in diagonal pairs (LF to RR and RF to LR) to change the static cross weight in the car.

BUMP STIFFNESS
The bump stiffness setting is a paired adjustment controlling both the low and high speed compression damping characteristics of the damper. In this case 0 is minimum damping (least resistance to compression) while 18 is maximum damping (most resistance to compression). Increasing the bump stiffness will result in a faster transfer of weight to this corner of the car during transient movements such as braking and direction change with increased damping usually providing an increase  inturn-in response but a reduction in overall grip in the context of front dampers. High speed compression damping will increase proportionally to the increase in low speed compression damping which will also result in harsher response to kerb strikes.  moother tracks more bump stiffness will typically increase performance while at rougher tracks or ones with aggressive kerbs less compression damping can result in an increase in mechanical grip at the expense of platform control.

REBOUND STIFFNESS
The Rebound Stiffness setting is a paired adjustment to both low and high speed rebound dampiharacteristics. Increasing rebound damping will slow down the rate at which the damper extends in both low and high speed situations. A typical low damper speed situation would be as the car rolls back to level on a corner exit while a high speed situation would be  where the suspensions extending after large kerb contact. 0 is minim damping (least resistance to extension) while 18 is  maximum damping (most resistance to extension). While homebound stiffness will result in improved platform control for aerodynamic performance and overall chassis response it is important to avoid situations where the shock is too slow in rebounding as this will result in the tire losing complete contact with the track surface which can induce or exacerbate severe oscillations.

CAMBER
Camber is the vertical angle of the wheel relative to the center of the chassis. Negative camber is when the top of the wheel is closer to the chassis centerline than the bottom of the wheel, positive camber is when the top of the tire is  farther out than the bottom. Due to suspension geometry and corner loads, negative camber is desired on all four wheels. Higher negative camber values will increase the cornering force generated by the tire, but will reduce the amount of longitudinal grip the tire will have under braking. Excessive camber values can produce very high cornering forces but will also significantly reduce tire life, so it is important to find a balance between life and performance. Increasing front camber values will typically result in increased front axle grip during mid to high speed cornering but will result in a loss of braking performance and necessitate a rearward shift in brake bias to compensate

LEFT/RIGHT REAR

SPRING RATE
Similar to at the front axle, stiffer springs will result in a smaller variance in ride height between high and low load cases and will produce superior aerodynamic performance through improved platform control at the expense of mechanical  grip. This can be particularly prominent when exiting slow speed corners witaggressive throttle application. Stiffer springs will tend to react poorly during these instances especially so on rougtracks which will result in significant traction loss. Spring stiffness should be matched to the needs of the racetrack and set such that the handling balance is consistent between high and low speed cornering. As an examplcase, a car which suffers from high speed understeer but low speed oversteer could benefit from an increase in rear spring stiffness. This will allow for a lower static rear height which will reduce rear weight transfer during slow speed cornering while maintaining or even increasing the rear ride height in high speed cornering to shift the aerodynamic balance forwards and re uce understeer. Two options for spring rate are available: 130 N/m(742 lbs/in) and 150 N/mm (857 lbs/ in). Spring perch offsets must be adjusted to return the car to the prior static ride heights after any spring rate change.

REAR RIDE HEIGHT
Distance from ground to a reference point on the rear of the chassis. Increasing rear ride height will decrease rear downforce as well as increase overall downforce and will allow for more weight transfer across the rear axle when cornering. Conversely, reducing ride height will increase rear downforce percentage but reduverall downforce while reducing theweight transfer across the rear axle. Rear ride height is a critical tunincomponent for both mechanical and aerodynamic  balance considerations and static rear ride heights should be considered and matched to the chosen rear corner springs for optimal performance. Minimum legal rear ride height i89.0 mm while maximum legal rear ride height is 100.0 mm.

BUMP STIFFNESS
The bump stiffness setting is a paired adjustment controlling both the low and high speed compressiodamping characteristics of the damper with identical ranges to those of the front dampers. Increasing the compression damping will result in a faster transfer of weight to this corner of the car during transient movements such as accelerating and direction change with increased damping usually providing an increase in response but a reduction in overall grip especially at corner exit traction in the context of rear dampers. Excessive suppression damping can cause very poor traction on rough tracks as it can result in large tire load variation and a reduction in overall g

REBOUND STIFFNESS
The rebound stiffness setting is a paired adjustment controlling both the low and high speed damparacteristics of the damper with identical ranges to those of the front dampers. Increasing rebound damping will slow down the rate at which the damper extends in both low and high speed situations. As at the front, high reboutiffness will result in improved platform control for aerodynamic performance and overall chassis response but it is important to avoid situations where the shock is too slow in rebounding as this will result in the tire complete contact with the track surface. This can be particularly detrimental during braking events and during the initial turn-in phase though an increase in rebound stiffness can help to ‘slow down’ the change in pitch of the car as the brakes are applied, potentially increasing braking stability

CAMBER
As at the front of the car it is desirable to run significant amounts of negative camber in order to increase the lateral grip capability; however, it is typical to run slightly reduced rear camber relative to the front. This is primarily for two reasons, firstly, the rear tires are wider compared to the fronts and secondly the rear tires must also perform the duty of driving the car forwards where benefits of camber to lateral grip become a tradeoff against reduced longitudinal (traction) performance

TOE-IN
At the rear of the car it is typical to run toe-in. Increases in toe-in will result in improved straight line stability and a reduction in response during direction changes. Large values of toe-in should be avoided if possible as this will increase rolling drag and reduce straight line speeds. When making rear toe changes remember that the values are for each individual wheel as opposed to paired as at the front. This means that individual values on the rear wheels are twice as powerful as the combined adjustment at the front of the car when the rear toes are summed together. Generally, it is advised to keep the left and right toe values equal to prevent crabbing or asymmetric handling behaviour; however, heavily asymmetric tracks such as Lime Rock Park may see a benefit in performance from running asymmetric configurations of rear toe and other setup parameters.

REAR

FUEL LEVEL
The amount of fuel in the fuel tank. Tank capacity is 87 L (23.0 g). Adjustable in 1 L (0.26 g) increments

ARB SETTING
Increasing the ARB assembly stiffness will increase the roll stiffness of the rear suspension, resulting in less body roll but increasing mechanical oversteer. This can also cause the car to “take a set” more quickly at initial turn-in. Conversely, reducing the ARB assembly stiffness will soften the suspension in roll, increasing body roll but decreasing mechanical oversteer. This can result in a less-responsive feel from the rear especial intransient movements, but grip across the rear axle will increase. Seven ARB settings are available ranging from 1 ‘soft’ to 7 ‘stiff’.

WING SETTING
The wing setting refers to the relative angle of attack of the rear wing, this is an aerodynamic device which has a significant impact upon the total downforce (and drag!) produced by the car as well as shifting aerodynamic balance of the car rearwards with increasing angle. Increasing the rear wing angle results in more totornering grip capability in medium to high speed corners but will also result in a reduction of straight line speed. Rear wing angle should be adjusted in conjunction with front and rear ride heights, specifically the differencbetween front and rear ride heights known as ‘rake’. To retain the same overall aerodynamic balance it is necessary to increase the rake of the car when increasing the rear wing angle.

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