iRacing MCLAREN 570S GT4 User manual

MCLAREN 570S GT4
USER MANUAL

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MCLAREN 570S GT4 // USER MANUAL
Introduction »5
Tech Specs »4
A Message From iRacing »3
Getting Started »5
Dash Pages »7
Loading An iRacing Setup »6
Pit Limiter & Shift Lights »8
Dash Cpnfiguration »7
Tires »10
Left/Right Front »13
Front »11
Rear »17
Chassis »11
Left/Right Rear »15
Brakes/In-Car »12
ADVANCED SETUP OPTIONS
GENERAL INFORMATION
Table of Contents
CLICK TO VIEW A SECTION

Dear iRacing User,
Congratulations on your purchase of the McLaren 570s GT4! From all of us at iRacing, 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 manufacturers can match the thrill of driving a McLaren in any class or specification, and the 570S,
the legendary brand’s foray into the world of GT4s, is no exception. Powered by a 3.8-liter twin turbo V8
engine and sitting on McLaren’s carbon fiber MonoCell II chassis, this highly agile machine is the car of
choice for a number of customer race teams competing in GT4 formula series around the world.
The 570S GT4 broke cover at the 2016 Goodwood Festival of Speed and made its competitive debut in
British GT under the brand’s own supervision that same year, allowing customers that took delivery of the
cars in 2017 to drive a racer that had been refined in real competition. Since then, it’s proven to be a highly
popular car with anyone who’s driven it, setting a high water mark of 140 global podium finishes in 2019.
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!

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MCLAREN 570S GT4 // USER MANUAL
POWER
UNIT
CHASSIS
MCLAREN 570S GT4 | TECH SPECS
MCLAREN CARBON FIBER MONOCELL II
CHASSIS WITH INDEPENDENT FRONT
AND REAR COILOVER SUSPENSION.
TWIN TURBO V8 M838TE
LENGTH
4,606 mm
181.3 in
DISPLACEMENT
3.8 Liters
231.9 cid
WIDTH
2,095 mm
82.5 in
TORQUE
355 lb-ft
481 Nm
WHEELBASE
2,674 mm
105.3 in
POWER
450 bhp
336 kW
DRY WEIGHT
1425 kg
3142 lbs
RPM LIMIT
7450
WET WEIGHT
WITH DRIVER
1540 kg
3395 lbs

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MCLAREN 570S GT4 // USER MANUAL
Introduction
The information found in this guide is intended to provide a deeper understanding of the
chassis setup adjustments 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 setups, simply open the Garage, click
iRacing 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, and hitting 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 between 6800 and 7300 rpm
depending on the currently selected gear.
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LOADING AN iRACING SETUP
Upon loading into a session, the car will automatically load the iRacing Baseline setup [baseline.sto]. If you would prefer one of
iRacing’s pre-built setups that suit various conditions, you may load it by clicking Garage > iRacing 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 the garage as well.
MCLAREN 570S GT4 // INTRODUCTION

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MCLAREN 570S GT4 // DASH PAGES
Dash Pages
DASH CONFIGURATION
Rear Dash row 1 left Total vehicle distance traveled (km or miles)
Rear Dash row 2 left Distance traveled in current session (km or miles) selected gear
Rear Dash row 3 left Distance traveled since last pitstop (km or miles)
Rear Dash vehicle graphic tires Tire pressure indicators for each tire
Rear Dash vehicle graphic top Engine oil level indicator
Rear Dash vehicle graphic center Engine water temperature indicator
Rear Dash vehicle graphic bottom Engine oil temperature indicator
Rear Dash lower right fill bar Graphical depiction of current fuel level along with percentage.
Rear Dash lower right Outside air temperature (Celsius or Fahrenheit)
Rear Dash far right ESC Status, off = Normal, Orange = Sport, Orange with ‘off’ = Track
Rear Dash far right bottom ABS activation indicator, illuminates orange when ABS is active.
Front Dash row 1 center Graphical gain/loss lap time depiction relative to session best lap.
Front Dash row 1 right Battery voltage indicator
Front Dash center Graphical depiction of engine rpm.
Front Dash row 2 left Engine water temperature (Celsius or Fahrenheit)
Front Dash row 2 center Currently selected gear
Front Dash row 2 right upper Last lap time as m:ss:ms
Front Dash row 2 right lower gain/loss lap time as ss:ms relative to session best lap.
Front Dash row 3 left Engine oil pressure (Bar or psi)
Front Dash row 3 right Fuel pressure (Bar or psi)

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MCLAREN 570S GT4 // USER MANUAL
PIT LIMITER
When the pit limiter is active a large blue box containing ‘PIT LIMITER ON’ will appear at the base of the
forward dashboard along with the illumination of the two centermost shift light LED’s.
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.
MCLAREN 570S GT4 // DASH PAGES
2 Green 6000 rpm
2 Yellow 6300 rpm
4 Yellow 6600 rpm
2 Red 6900 rpm

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MCLAREN 570S GT4 // USER MANUAL
Advanced Setup Options
This section is aimed toward more advanced users who want to
dive deeper into the different aspects of the vehicle’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.
MCLAREN 570S GT4 // ADVANCED SETUP OPTIONS

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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 will increase grip. Higher speeds and loads require
higher pressures, while lower speeds and loads will see better 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 tires seeing 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 pressures should be adjusted to ensure that similar tires are at similar
pressures once up to operating temperature. Hot 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 by each 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 in identifying 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.
MCLAREN 570S GT4 // TIRES

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Chassis
FRONT
ARB SETTING
Increasing the ARB setting shortens the ARB moment arm and will increase the roll stiffness of the front suspension, resulting in
less 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. Two ARB settings are available; 1 is ‘soft’ and 2 is ‘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 hand corners providing all other chassis settings
are symmetrical. Higher than 50% cross weight will result in more 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.
MCLAREN 570S GT4 // CHASSIS

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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 balance forwards 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 friction and
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). Three options are
available: ‘Normal’ which provides maximum TC and ABS assistance, ‘Sport’ which provides a reduced level of TC and ABS
assistance and ‘Track’ which provides the lowest levels of TC and ABS intervention. ‘Track’ is the recommended setting.
MCLAREN 570S GT4 // CHASSIS

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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 reference 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 overall 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 77.0 mm.
SPRING RATE
This setting determines the installed corner spring stiffness. 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; however, they
will also result in increased tire load variation which will manifest as a loss in mechanical grip. Typically the drawbacks of stiffer
springs will become more pronounced on rougher tracks and softer springs in these situations will result in increased overall
performance. Corner spring changes will influence both roll and pitch control of the platform and ARB changes should be
considered when altering corner spring stiffnesses in order to retain the same front to rear roll stiffness and overall balance.
When reducing corner spring stiffness the ARB stiffness should be increased to retain the same roll stiffness as previously.
Two options for spring rate are available 140 N/mm (799 lbs/in) and 175 N/mm (999 lbs/in). Spring perch offsets must be
adjusted to return the car to the prior static ride heights after any spring rate change.
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SPRING PERCH OFFSET
Used to adjust the ride height at this corner of the car by changing the installed position of the spring. Increasing 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 in turn-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. At smoother 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 damping characteristics. 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 suspension
is extending after large kerb contact. 0 is minimum damping (least resistance to extension) while 18 is maximum damping (most
resistance to extension). While high rebound 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.
MCLAREN 570S GT4 // CHASSIS

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MCLAREN 570S GT4 // USER MANUAL
LEFT/RIGHT REAR
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 reduce overall downforce while reducing the weight transfer
across the rear axle. Rear ride height is a critical tuning component 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 is 90.0 mm.
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 with aggressive throttle application. Stiffer springs will tend to react
poorly during these instances especially so on rough tracks 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 example case, 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 reduce understeer. Two options for spring rate are available: 228 N/mm (1299 lbs/in) and 245 N/mm (1399
lbs/in). Spring perch offsets must be adjusted to return the car to the prior static ride heights after any spring rate change.
BUMP STIFFNESS
The bump stiffness setting is a paired adjustment controlling both the low and high speed compression damping 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. Excessively stiff compression damping can cause very poor traction on rough tracks as it can result in large
tire load variation and a reduction in overall grip.
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REBOUND STIFFNESS
The rebound stiffness setting is a paired adjustment controlling both the low and high speed damping characteristics 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 rebound stiffness 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 losing 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.
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REAR
FUEL LEVEL
The amount of fuel in the fuel tank. Tank capacity is 110 L (29.1 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 especially in transient movements, but grip across the rear axle will increase. Two ARB
settings are available; 1 is ‘soft’ and 2 is ‘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 the aerodynamic balance of the car rearwards with
increasing angle. Increasing the rear wing angle results in more total cornering 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 difference between 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.
MCLAREN 570S GT4 // CHASSIS