iRacing FIA F4 Racing Car User Manual
- June 12, 2024
- iRacing
Table of Contents
FIA F4
USER MANUAL
FIA F4 Racing Car
GENERAL INFORMATION
A Message From iRacing
DEAR iRACING USER,
Congratulations on your purchase of the fia f4! 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!
The iRacing Formula fia f4 has been developed in conjunction with the global
effort to massively increase the participation of motorsport worldwide.
Following the introduction of a second-generation entry-level open wheel
formula in 2022, the iRacing Formula fia f4 benefits from the same level of
analysis, detail, data, and testing as our members have come to expect while
the genericized model allows for use by national clubs world-over without
manufacturer conflicts. iRacers have their choice of the GT2 and GT3 versions
of the Ford GT.
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!
TECH SPECS
CHASSIS
DOUBLE WISHBONE PUSHROD SUSPENSION FRONT AND REAR
LENGTH
4467mm
175.9in| WIDTH
1738mm
68.4in| WHEELBASE
2745mm
108.1in| DRY WEIGHT
581kg
1281lbs| WET WEIGHT
WITH DRIVER
665kg
1466lbs
---|---|---|---|---
POWER UNIT
INLINE-4
DISPLACEMENT
2.0Liters
122.0CID| TORQUE
226Nm
167lb-ft| POWER
178bhp
131kW| RPM LIMIT
7275RPM
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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 a control for Brake Bias
adjustment. While this is not mandatory, this will allow you to make quick
changes to the brake bias 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.
Upshifting is recommended when the shift lights on the dashboard are all fully
illuminated. This is at 7000rpm.
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.
Dash Pages
The dash display in this car is non-adjustable and features a single page to display critical vehicle information.
DASH CONFIGURATION
Row 1 Left | Engine oil pressure (Bar or psi) |
---|---|
Row 1 Center | Engine rpm |
Row 1 Right | Engine water temperature (Celsius or Fahrenheit) |
Row 2 Left | Engine oil temperature (Celsius or Fahrenheit) |
Row 2 Center | Currently selected gear |
Row 2 Right | Road speed (km/h or mph) |
Row 3 Left | Session best lap as mm:ss:ms |
Row 3 Right | Session last lap as mm:ss:ms |
PIT LIMITER
1 Green | 6300 RPM |
---|---|
2 Green | 6500 RPM |
3 Green | 6600 RPM |
4 Green | 6700 RPM |
1 Red | 6800 RPM |
2 Red | 6900 RPM |
All Flashing | 7000 RPM |
When the pit limiter is activated a large green box will appear at the base of the dash display.
SHIFT LIGHTS
1 Green | 6300 rpm |
---|---|
2 Green | 6500 rpm |
3 Green | 6600 rpm |
4 Green | 6700 rpm |
1 Red | 6800 rpm |
2 Red | 6900 rpm |
All Flashing | 7000 rpm |
HALO CENTER PILLAR
To improve driver visibility, the halo can be removed via the “Hide Obstructions” setting in the Options menu. To enable this option go to the Options and then Graphics menu, then change the “Hide Obstructions” setting to either “Cockpit halo” or “All”. This will remove the screen completely but it will still be visible in replays
ADVANCED SETUP OPTIONS
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.
Tires & Aero
TIRE SETTINGS (ALL FOUR)
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.
FIA F4 // TIRES & AERO
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.
AERO
FRONT MAINPLANE ANGLE
The relative angle of attack of the front wing. This is a powerful aerodynamic
device in terms of balance and total downforce produced. Increasing the front
mainplane angle results in more total cornering capability in medium to high
speed corners, a significant shift forwards in handling balance (more
oversteer) and a slight reduction in straight line speed. The front mainplane
angle should be adjusted in conjunction with the rear wing angle as well as
the relative difference in front and rear ride heights known as `rake’.
Reducing the rake will shift the aerodynamic balance rearwards while
increasing it will shift the aerodynamic balance forwards.
REAR WING SETTING
The relative angle of attack of the rear wing. On this car the primary purpose
of the rear wing is to trim the aerodynamic balance to suit changes made to
the front mainplane angle. Increasing the rear wing angle will produce more
downforce, more drag and shift the aerodynamic balance rearwards (more
understeer). In both balance and downforce senses it is relatively less
powerful than the front mainplane and will require larger step changes to suit
any changes made to the front mainplane. However, it is relatively more
influential in terms of drag. As such, at tracks with long straights it may be
beneficial to focus on reducing the rear wing angle for greater straight line
speed to aid in overtaking.
AERO CALCULATOR
The Aero Calculator is a tool provided to aid in understanding the shift in aerodynamic balance associated with adjustment of the rear wing setting and front and rear ride heights. It is important to note that the values for front and rear ride height displayed here DO NOT result in any mechanical changes to the car itself, however, changes to the rear wing angle here WILL be applied to the car. This calculator is a reference tool ONLY.
REAR RH AT SPEED
The Ride Height (RH) at Speed is used to give the Aero Calculator heights
to reference for aerodynamic calculations. When using the aero calculator,
determine the car’s Rear Ride height via telemetry at any point on track and
input that value into the “Front RH at Speed” setting. It is advisable to use
an average value of the LR and RR ride heights as this will provide a more
accurate representation of the current aero platform rather than using a
single corner height.
DOWNFORCE TO DRAG
In absolute terms this number represents the amount of downforce produced per
unit drag and thus represents the overall aerodynamic efficiency of the
currently selected wing configuration and at speed ride heights. This can be
useful in evaluating various combinations of wings and rake while keeping an
equivalent downforce to drag number. However, it should be noted that this
number only represents the efficiency, not the total downforce produced. As
such, it is very possible to create two different packages that have the same
efficiency but very differing levels of performance in terms of mid corner and
end of straightaway speeds.
FRONT DOWNFORCE
This value displays the proportion of downforce acting at the front axle for
the given wing and ride height combination set within the calculator
parameters. This value is an instantaneous representation of your aero balance
at this exact set of parameters and it can be helpful to pick multiple points
around a corner or section of track to understand how the aerodynamic balance
is moving in differing situations such as braking, steady state cornering and
accelerating at corner exit. A higher forwards percentage will result in more
oversteer in mid to high speed corners.
Chassis
FRONT
TRANSPARENT HALO COLUMN
This option is visual only. Checking this box will change the center support
of the halo from opaque to transparent.
PUSHROD OFFSET
Used to adjust the front ride height by increasing or decreasing the length of
the front pushrods. Lengthening the pushrod will increase the ride height and
shortening the pushrod will reduce the ride height. Left and right adjustments
are paired and adjusted as one.
ARB BLADES
The configuration of the Anti-Roll Bar arms, or “blades”, can be changed to
alter the overall stiffness of the ARB assembly. Increasing the number of ARB
arms will increase the roll stiffness of the front suspension, resulting in
less body roll but increasing mechanical understeer. This can also, in some
cases, lead to a more responsive steering feel from the driver. Conversely,
reducing the number of ARB arms will soften the suspension in roll, 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, softer ARB
assemblies 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. 5 configurations of ARB arms are available and range from 1
(softest) to 5 (stiffest).
DAMPER COMPRESSION 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 1
is minimum damping (least resistance to compression) while 10 is maximum
damping (most resistance to compression). Increasing the bump stiffness will
result in a faster transfer of weight to this end 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 damping. 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.
DAMPER 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. 1 is minimum damping (least
resistance to extension) while 10 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 damper 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.
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.
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, adjustments to cross weight can be made by
making changes to the corner spring rates, air pressures or alignment at each
corner of the car.
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. For the fia f4 this cannot be easily influenced as
individual corner pushrods are non-adjustable. However, when running
asymmetrical setups some difference in corner weights may still be observed.
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 20.0 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. Six
options for spring rate are available ranging from 88 N/mm (500 lbs/in) to 175
N/mm (1000 lbs/in). Pushrod offsets must be adjusted to return the car to the
prior static ride heights after any spring rate change.
CASTER
Caster is the vertical angle of the steering axis relative to the side view of
the chassis. Positive caster angle is where the steering axis is leaned
rearwards from this viewpoint, the more caster the larger the total trail of
the contact patch behind the steering axis. More caster angle will result in
the mechanical trail being a larger proportion of the felt steering weight
relative to the tires pneumatic trail. This will result in a heavier overall
steering feel but a possible loss in felt feedback from the tire. Increasing
caster angle will also have secondary effects such as an increase in dynamic
camber when turning the wheel through large steering angles which can be
beneficial in chicances or hairpins. As well as this the more caster angle the
greater the jacking effect during cornering which will result in lifting the
inside front wheel while lowering the outside front wheel. This jacking effect
will also result in the unloading and potentially lifting of the inside rear
wheel which can aid in rotation around tight corners.
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.
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 while adding
toe-in will reduce the slip. This can be used to increase straight-line
stability; more toeout results in more straight line stability but increased
rolling drag. Generally, it is best to keep to small values here due to the
low power nature of the car.
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 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. Six
options for spring rate are available 88 N/mm (500 lbs/in) to 175 N/mm (1000
lbs/in). Pushrod offsets must be adjusted to return the car to the prior
static ride heights after any spring rate change.
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. Generally, it
is advised to keep the left and right toe values equal to prevent crabbing or
asymmetric handling behavior; 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
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 30.0 mm while maximum legal
rear ride height is 40.0 mm.
PUSHROD OFFSET
Used to adjust the rear ride height by increasing or decreasing the length of
the rear pushrods. Lengthening the pushrod will increase the ride height and
shortening the pushrod will reduce the ride height. Left and right adjustments
are paired and adjusted as one.
ARB BLADES
The configuration of the Anti-Roll Bar arms, or “blades”, can be changed to
alter the overall stiffness of the ARB assembly. 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. 5 configurations of ARB arms are available and range from
1 (softest) to 5 (stiffest).
DAMPER COMPRESSION 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 end 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.
DAMPER 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 damper 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.
FUEL LEVEL
The amount of fuel in the fuel tank. Tank capacity is 40 L (10.6 g).
Adjustable in 1 L (0.26 g) increments.
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