iRacing BMW M HYBRID V8 GPT Race Car User Manual
- June 9, 2024
- iRacing
Table of Contents
BMW M HYBRID V8 GPT Race Car User Manual
BMW M HYBRID V8 GPT Race Car
Dear iRacing User,
BMW’s long-awaited return to the highest ranks of prototype racing comes in
2023, as the German manufacturer teams up with chassis partner Dallara and
team partner Rahal Letterman Lanigan Racing to bring the BMW M Hybrid V8 to
the IMSA WeatherTech SportsCar Championship. Built to a new set of global
prototype regulations, two M Hybrid V8s will compete in IMSA’s premier GTP
class, but countless more reproductions of the car are set to debut on iRacing
before its first racing lap.
Years of coordinated efforts in both North America and Europe to create a
unified top-level rule set have allowed top-tier manufacturers to return to
the prototype ranks, with BMW becoming one of the first to announce its
involvement. The M Hybrid V8 produces approximately 640 horsepower out of its
four-liter power plant alone, with its electric motor able to add even more
boost.
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!
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,
Traction Control and ABS adjustments. While this is not mandatory to drive the
car, this will allow you to make quick changes to the driver aid systems to
suit your driving style while out on the track.
Once you load into the car, getting started is as easy as selecting the
“upshift” button to put it into gear, and hitting the accelerator pedal. This
car uses a sequential transmission and does not require a clutch input 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
selected and would incur engine damage. If that is the case, the gear change
command will simply be ignored.
Upshifting is recommended when the final shift light on the dashboard is
illuminated in red. This is at 7100 rpm. Note; all shift lights will flash red
at 7200 rpm as an additional warning however, this is beyond the optimal shift
point.
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 Configuration
The BMW M Hybrid V8 features a single-page, steering wheel mounted display to provide the driver with useful information in an easy-to-read format.
LEFT COLUMN
Type Pressure| Current air pressure in each tire, updated live and displayed
in either PSI or Bar.
---|---
Lap Fuel| The amount of fuel used in the previous lap, in either gallons or
liters, is updated at the end of each lap.
Fuel Used| The amount of fuel that has been used, in gallons or liters, since
the fuel was last added to the car.
SOC| Current battery charge level, in percent.
CENTER COLUMN
RPM | The current engine RPM is shown at the top of the center section. |
---|---|
Gear Indicator | The currently-selected gear is shown as a large number in the |
center of the display.
BEAM| If the car’s nighttime light system is on, this indicator will appear in
the lower left of the center area.
Tyre| Inoperable
BRKB| Inoperable
LOWER GROUP
TC1 | Displays the current Traction Control Gain setting. |
---|---|
TC2 | Displays the current Traction Control Slip setting. |
FARB | Displays the current setting for the Front Anti-Roll Bar. |
RARB | Displays the current setting for the Rear Anti-Roll Bar. |
Lap Predict | The onboard systems will attempt to predict the current lap time |
based on splits.
Last Lap| The previously completed lap time, updated and displayed at the end
of each lap.
Best Lap| The fastest lap of the current session.
TMOT| The engine’s cooling fluid temperature, in either °F or °C.
TOIL| Engine oil temperature, in either °F or °C.
LAP| Displays the number of laps completed in the current session.
PWAT| Engine cooling fluid pressure, in PSI or Bar
POIL| Engine Oil system pressure, in PSI or Bar
TGBX| Gearbox oil temperature, in °F or °C.
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)
STARTING 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 will 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.
LAST HOT 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.
LAST TEMPS OMI
Tire carcass temperatures once the car has returned from the pits. Wheel loads
and the amount of work a tire is doing on-track is 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 while on track. These values are measured in three zones
across the tread of the tire.
TREAD REMAINING
The amount of tread remaining on the tire once the car has returned from 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 three zones across the tread of the tire.
AERO SETTINGS
REAR WING ANGLE
The rear wing angle setting changes the Angle of Attack of the wing elements.
Increasing wing angle increases the downforce generated by the wing but
increases drag, while decreasing the wing angle reduces the downforce
generated by the wing while reducing drag. Rear wing angle has a heavy
influence on rear downforce, having a heavy influence on rear-end grip in
mid- to highspeed corners.
AERO CALCULATOR
The Aero Calculator is a tool used to display the car’s approximate aerodynamic values in a given configuration. Changes to the car’s aerodynamic settings (Wing Angles, Dive Planes, Gurney Flaps) will be reflected in the Aero Calculator, giving an idea of how the car will behave aerodynamically while on the race track. This calculator can also be used to determine what changes need to be made to the car to alleviate aerodynamically-induced handling issues.
FRONT/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 Front and Rear Ride height via telemetry at any point on
track and input that value into the “Front RH at Speed” setting.
DOWNFORCE DELTA
The Downforce Delta is a numerical representation of how much the baseline
aero map has been altered with the car’s current configuration in terms of
downforce. Downforce is represented as a negative lift, so higher Delta
values indicate a decrease in downforce while lower values indicate an
increase in downforce.
DRAG DELTA
The Drag Delta is a numerical representation of how much the baseline aero map
has been altered with the car’s current configuration in terms of drag. The
value shows how much the total drag has been offset from the baseline values
with higher values indicating an increase in drag while lower values indicate
a decrease in drag.
DOWNFORCE BALANCE
Displayed in percent of Front downforce, this value shows how much of the
car’s total downforce is over the front axle. A higher percentage value
indicates more front downforce, increasing oversteer in mid- to high-speed
corners and a lower percentage value indicates more rear downforce, increasing
understeer in mid- to high-speed corners.
L /D
The “L/D” value is the ratio of Lift (downforce) to Drag. This quantifies how
efficiently the car’s bodywork is producing downforce in terms of how much
drag is being produced as a result. A higher L/D value means more downforce
is being produced for each unit of drag, meaning the bodywork is being more
efficient. Having a higher L/D value without sacrificing overall downforce
will result in a faster, more efficient car. Optimum values for L/D can vary
based on the aerodynamic configuration and track type.
Chassis
FRONT
HEAVE SPRING
The front Heave Spring is a suspension element that handles external loads
from purely vertical loads and doesn’t control loads that would induce chassis
roll when cornering. Generally these loads are present for increasing
downforce loads at higher speeds, dips and crests in the track, or under heavy
braking. Higher rate values will stiffen the suspension in heave, which is
good for controlling ride heights to maintain a good aerodynamic platform, but
can produce a bouncing effect on rough surfaces. Lower rates will absorb
bumps and loads easier, but will hurt the aerodynamic platform due to
excessive chassis movement.
HEAVE PERCH OFFSET
The Heave Perch Offset is used to adjust preload on the Heave Spring. This is
one of two methods to adjust ride height through the front Heave element, with
lower values preloading the spring more and raising front ride heights.
Conversely, higher values will unload the spring and lower front ride heights.
HEAVE SPRING DEFL
Heave Spring Deflection represents the amount the Heave Spring is compressed
under static conditions. This is not directly adjustable but will change with
adjustments to the Heave Perch Offset and front Torsion Bar settings.
HEAVE SLIDER DEFL
The Slider Deflection is how far the slider mechanism the Heave Spring is
mounted on has compressed from fully extended.
Similar to a shock but without any damping forces produced, this doesn’t
influence the suspension’s behavior.
ARB SIZE
The ARB (Anti-Roll Bar) size alters the stiffness of the front suspension in
roll. Increasing the ARB size 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 ARB size 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.
ARB BLADES
The configuration of the Anti-Roll Bar arms, or “blades”, can be changed to
alter the overall stiffness of the ARB assembly. Higher values transfer more
force through the arms to the ARB itself, increasing roll stiffness in the
front suspension and producing the same effects, albeit on a smaller scale, as
increasing the diameter of the sway bar. Conversely, lower values reduce the
roll stiffness of the front suspension and produce the same effects as
decreasing the diameter of the sway bar. These blade adjustments can be
thought of as fine-tuning adjustments between sway bar diameter settings
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 amount of slip. This can be used to increase
straight-line stability and turn-in responsiveness with toe-out. Toe-in at the
front will reduce turn-in responsiveness but will reduce temperature buildup
in the front tires.
PUSHROD LENGTH OFFSET
This adjusts the length of both front suspension pushrods together, shown as
an offset from a baseline length figure. This is a great way to adjust front
ride height without altering the preload on the Heave Spring or either front
Torsion Bars.
FRONT CORNERS
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 Torsion Bar Turns setting on the front corners
and the Spring Perch Offset on the rear corners.
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 the front ride height will decrease overall downforce and
shift the aerodynamic balance rearward, but will decrease drag slightly.
Conversely, reducing front ride height will increase downforce and shift aero
balance forward while slightly increasing overall drag.
SHOCK DEFLECTION
Shock Deflection is how much the shock has compressed from its fully extended
length while under static conditions in the garage.
This is useful for determining how much shock travel is available before a
bump stop is engaged on the shock.
TORSION BAR DEFLECTION
The Torsion Bar Deflection is a representation of how much the front torsion
bar springs have been preloaded under static conditions. Higher deflection
values show higher amounts of spring preload, lower values represent less
spring preload.
TORSION BAR TURNS
Used to adjust ride height and corner weight, adjusting this setting applies a
preload to the torsion bar under static conditions.
Decreasing the value increases preload on the torsion bar, adding weight to
its corner and increasing the ride height at that corner. Increasing the value
does the opposite, reducing height and weight on a given corner. These should
be adjusted in pairs (left and right, for example) or with all four spring
preload adjustments in the car to prevent crossweight changes while adjusting
ride height.
TORSION BAR O.D.
Similar to an Anti-Roll Bar, a torsion bar is a spring that exerts resistive
forces via applied torque generated through suspension travel. However, these
torsion bars are fixed to the chassis at one end, and thus resist movement
only on one wheel in the same way a coil spring resists movement and load
changes. Increasing the torsion bar’s diameter gives a higher spring rate,
and reducing the diameter gives a lower spring rate. Stiffer springs are very
helpful for smooth tracks and applications where a high level of aerodynamic
attitude control is required, however stiff springs reduce mechanical grip
significantly, especially over bumps. On low-grip and/or bumpy tracks, as well
as lower speed tracks where aerodynamics may not be as effective, softer
springs will increase mechanical grip while sacrificing aerodynamic control.
Torsion Bar Diameter adjustments should be made in conjunction with ride
height adjustments to prevent unwanted grounding of the chassis while on
track.
LS COMP DAMPING
Low Speed Compression affects how resistant the shock is to compression
(reduction in length) when the shock is moving at relatively low speeds,
usually in chassis movements as a result of driver input (steering, braking,
& throttle) and cornering forces.
Higher values will increase compression resistance and transfer load onto a
given tire under these low-speed conditions more quickly, inducing understeer.
Lower values will slow weight transfer to a tire, reducing understeer when
applied to the front shocks.
HS COMP DAMPING
High Speed Compression affects the shock’s behavior in high-speed travel,
usually attributed to curb strikes and bumps in the track’s surface. Higher
compression values will cause the suspension to be stiffer in these
situations, while lower values will allow the suspension to absorb these bumps
better but may hurt the aerodynamic platform around the track.
LS REBOUND DAMPING
Low-speed Rebound damping controls the stiffness of the shock while extending
at lower speeds, typically during body movement as a result of driver inputs.
Higher rebound values will resist expansion of the shock, lower values will
allow the shock to extend faster. Higher rebound values can better control
aerodynamic attitude but can result in the wheel being unloaded when the
suspension can’t expand enough to maintain proper contact with the track. When
tuning for handling, higher front low-speed rebound can increase on-throttle
mechanical understeer (but reduce splitter lift) while lower values will
maintain front end grip longer, helping to reduce understeer, but will allow
more splitter lift. Excessive front rebound can lead to unwanted oscillations
due to the wheel bouncing off of the track surface instead of staying in
contact.
HS REBOUND DAMPING
High-speed rebound adjusts the shock in extension over bumps and curb strikes.
Higher values will reduce how quickly the shock will expand, while lower
values will allow the shock to extend more easily. Despite not having as much
of an effect on handling in result to driver inputs, High-speed rebound can
produce similar results in terms of aerodynamic control and uncontrolled
oscillations if set improperly.
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.
REAR CORNERS
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 setting.
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. Raising the rear ride height will increase overall downforce and shift
aero to the front of the car but will increase drag. Decreasing rear ride
height will do the opposite, with aero shifting rearward and overall downforce
and drag decreasing.
SHOCK DEFLECTION
Shock Deflection is how much the shock has compressed from its fully extended
length while under static conditions in the garage.
This is useful for determining how much shock travel is available before a
bump stop is engaged on the shock.
SPRING DEFLECTION
Spring Deflection shows how much the spring has compressed from its unloaded
length. This can be used to see spring preload under static conditions and
compare it against other corners of the car, with higher values representing
more preload on a given spring.
SPRING PERCH OFFSET
Used to adjust ride height and corner weight, adjusting this setting applies a
preload to the spring under static conditions.
Decreasing the value increases preload on the spring, adding weight to its
corner and increasing the ride height at that corner.
Increasing the value does the opposite, reducing height and weight on a given
corner. These should be adjusted in pairs (left and right, for example) or
with all four spring preload adjustments in the car to prevent crossweight
changes while adjusting ride height.
SPRING RATE
Spring Rate changes how stiff the spring is, represented in a force per unit
of displacement. Primarily responsible for maintaining ride height and
aerodynamic attitude under changing wheel loads, stiffer springs will
maintain the car’s aero platform better while sacrificing mechanical grip.
Softer springs will deal with bumps better and increase mechanical grip, but
will cause the car’s aerodynamic platform to suffer. Due to homologation
rules, rear spring rates must be symmetrical across the rear axle and can only
be changed in pairs.
LS COMP DAMPING
Low Speed Compression affects how resistant the shock is to compression
(reduction in length) when the shock is moving at relatively low speeds,
usually in chassis movements as a result of driver input (steering, braking,
& throttle) and cornering forces.
Higher values will increase compression resistance and transfer load onto a
given tire under these low-speed conditions more quickly, inducing understeer
on throttle application.
HS COMP DAMPING SLOPE
The Compression Damping Slope setting controls the overall shape of the high-
speed compression side of the shock. Lower slope values produce a flatter,
more digressive curve while higher values result in a more linear and
aggressive compression graph. The value of the slope setting is very important
in controlling bump absorption at high shock velocities and controlling the
aerodynamic platform. A lower slope will be helpful for rougher tracks in
absorbing bumps and sharp impacts such as curbs, while a higher slope will
keep the suspension more rigid. It’s important to understand that these
settings will affect the range the High-Speed Compression will have, with
higher slope values producing a higher overall force for high-speed
compression.
LS REBOUND DAMPING
Low-speed Rebound damping controls the stiffness of the shock while extending
at lower speeds, typically during body movement as a result of driver inputs.
Higher rebound values will resist expansion of the shock, lower values will
allow the shock to extend faster. Higher rebound values can better control
aerodynamic attitude but can result in the wheel being unloaded when the
suspension can’t expand enough to maintain proper contact with the track. When
tuning for handling, higher rear low-speed rebound can increase off-throttle
mechanical understeer (but reduce rear-end lift) while lower values will
maintain rear end grip longer, helping to reduce oversteer, but will allow
more rear end lift under deceleration. Excessive rear rebound can lead to
unwanted oscillations due to the wheel bouncing off of the track surface
instead of staying in contact.
HS REBOUND DAMPING
High-speed rebound adjusts the shock in extension over bumps and curb strikes.
Higher values will reduce how quickly the shock will expand, while lower
values will allow the shock to extend more easily. Despite not having as much
of an effect on handling in result to driver inputs, High-speed rebound can
produce similar results in terms of aerodynamic control and uncontrolled
oscillations if set improperly.
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 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. Higher rear camber values can increase cornering stability but
reduce stability under braking.
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 rear end, adding toe-in will increase straight-line stability but may hurt
how well the car changes direction.
REAR
THIRD SPRING
The Third Spring, similar to the front Heave Spring, is a spring element
configured to provide resistance only in vertical suspension movement without
affecting roll stiffness. This spring element is helpful with controlling
increasing aerodynamic loads and maintaining the proper aerodynamic attitude
around a circuit. The rear end’s third spring is crucial in maintaining and
controlling the rear ride height around a circuit to maximize the downforce
produced by the rear bodywork.
THIRD PERCH OFFSET
The Third Perch Offset is used to adjust preload on the rear Third Spring.
This is one of two methods to adjust ride height through the rear Third Spring
element, with lower values preloading the spring more and raising front ride
heights. Conversely, higher values will unload the spring and lower front ride
heights.
THIRD SPRING DEFLECTION
Third Spring Deflection represents the amount the rear Third Spring is
compressed under static conditions. This is not directly adjustable but will
change with adjustments to the Third Perch Offset and rear Spring settings.
THIRD SLIDER DEFLECTION
The Slider Deflection is how far the slider mechanism the Third Spring is
mounted on has compressed from fully extended. Similar to a shock but without
any damping forces produced, this doesn’t influence the suspension’s behavior.
ARB SIZE
The ARB (Anti-Roll Bar) size alters the stiffness of the rear suspension in
roll. Increasing the ARB size will increase the roll stiffness of the rear
suspension, resulting in less body roll but increasing mechanical oversteer.
Conversely, reducing the ARB size will soften the suspension in roll,
increasing body roll but decreasing mechanical oversteer. This can result in
a less-responsive feel from the steering, but grip across the rear axle will
increase.
ARB BLADES
The configuration of the Anti-Roll Bar arms, or “blades”, can be changed to
alter the overall stiffness of the ARB assembly. Higher values transfer more
force through the arms to the ARB itself, increasing roll stiffness in the
rear suspension and producing the same effects, albeit on a smaller scale, as
increasing the diameter of the Anti-roll bar. Conversely, lower values reduce
the roll stiffness of the rear suspension and produce the same effects as
decreasing the diameter of the Anti-roll bar. These blade adjustments can be
thought of as fine-tuning adjustments between Anti-roll bar diameter settings.
PUSHROD LENGTH OFFSET
This adjusts the length of both front suspension pushrods together, shown as
an offset from a baseline length figure. This is a great way to adjust front
ride height without altering the preload on the Heave Spring or either front
Torsion Bars.
CROSSWEIGHT
Cross weight is the amount of weight on the car’s Left-Rear and Right-Front
tires relative to the entire weight of the car, displayed in percent. This is
adjusted via the corner spring preload adjustments (Front Torsion Bar Turns
and Rear Spring Perch Offset). This value should be around 50% for most
tracks.
Brakes/Drive Unit
BRAKE SPEC
PAD COMPOUND
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 allowing for better brake pressure modulation, while “Medium”
and “High” provide more friction and increase the effectiveness of the brakes
while increasing the risk of a brake lockup.
PAD COMPOUND
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 allowing for better brake pressure modulation, while “Medium”
and “High” provide more friction and increase the effectiveness of the brakes
while increasing the risk of a brake lockup.
REAR MASTER CYLINDER
The Rear Brake Master Cylinder size can be changed to alter the line pressure
to the rear brake calipers. A larger master cylinder will reduce the line
pressure to the rear brakes, which will shift the brake bias forwards and
increase the pedal effort required to lock the rear wheels. A smaller master
cylinder will increase brake line pressure to the rear brakes, shifting brake
bias rearward and reducing required pedal effort to lock the rear wheels.
BRAKE PRESSURE BIAS
Brake Bias is the percentage of braking force that is being sent to the front
brakes. Values above 50% result in more pressure being sent to the front,
while values less than 50% send more force to the rear. This should be tuned
for both driver preference and track conditions to get the optimum braking
performance for a given situation.
HYBRID CONFIG
MGU-K DEPLOY MODE
The Hybrid power system on the BMW V8 can be set to one of five modes to
change the target battery State of Charge (SoC) after each lap. Each of these
modes will use varying levels of energy throughout a lap to reach a target,
and thus some will produce more power over the course of a lap and faster lap
times at the cost of discharging the battery.
- No Deploy – In the “No Deploy” mode, the Hybrid system will not use any energy stored in the battery. This essentially disables the Hybrid drive system and will only charge the battery throughout a lap. This is only available in Qualifying and Test sessions and is used to fully charge the battery before switching to Qual mode.
- Qual – This mode is intended to be used on flying laps during qualifying sessions and will attempt to use all of the battery charge during a lap. This is only available during Qualifying and Test sessions and should be preceded by the No Deploy setting on outlaps and warm-up laps to ensure the battery is fully charged before switching to the Qual mode.
- Attack – Attack mode reduces the target State of Charge to use more power during race sessions to help with overtaking. Generally the laptime gain from this mode is not enough to offset the loss in pace from having to recharge and recover from using Attack mode, so it should be used only when it is absolutely necessary to complete an overtake. This mode can also be used on the final lap for a burst of speed since the battery is no longer needed. This mode is only available for Practice, Race, and Test sessions
- Balanced – The Balanced mode is the primary Race mode for the Hybrid system. This mode will attempt to deploy electrical charge to reduce lap times as much as possible while still maintaining a reasonable State of Charge over the duration of a lap. At the start of a session, it will take a few flying laps for the Hybrid system to learn the track and optimize deployment for the best lap times, and this mode is only available in Practice, Race, and Test sessions
- Build – The Build mode will attempt to build battery charge as quickly as possible in the event of a low battery charge or if it is needed prior to switching to Attack mode. Note that this will compromise lap times significantly compared to Balanced, and it’s important to switch back to Balanced mode once the battery has charged to avoid losing harvested energy and to prevent unnecessary loss in pace. This mode is only available in Practice, Race, and Test sessions.
FUEL
FUEL
Fuel level is the amount of fuel in the fuel tank when the car leaves the
garage.
TRACTION CONTROL
TRACTION CONTROL GAIN
Gain is the amount of intervention the Traction Control will exert when wheel
spin is detected. Higher values result in a more aggressive throttle cut to
control wheel-spin.
TRACTION CONTROL SLIP
Slip is how sensitive the Traction Control system will be to wheel-spin.
Higher values will activate the Traction Control system with smaller amounts
of wheel-spin, while lower values will allow slightly more wheel-spin prior to
activating the system.
GEAR RATIOS
GEAR STACK
Gear Stack changes the gear ratios in the transmission. Two choices are
available: Short and Long. The Short setting will choose a more acceleration-
focused gear set for tracks with shorter straights or slower corners, while
the Long option will choose gears more suited to high-speed tracks with long
straights.
GEAR SPEEDS
Each of the transmission’s seven forward gears will show the approximate
ground speed at which the engine will reach maximum RPM. These values will
change based on which Gear Stack is selected, but the true maximum speed may
differ slightly due to ontrack conditions.
COAST/DRIVE RAMP ANGLES
Coast and Drive Ramp Angles affect the force exerted by the differential to
keep both driven tires locked together under acceleration. Lower values
produce more locking force, and more locking force increases understeer
during braking and acceleration phases. Higher values will produce less
locking force and induce oversteer in these situations.
CLUTCH FRICTION PLATES
The number of clutch faces affect how much overall force is applied to keep
the differential locked. Treated as a multiplier, adding more faces produces
increasingly more locking force.
PRELOAD
The differential can be set with a static load applied. Higher values produce
more locking force in the differential in all conditions, producing more
understeer under acceleration and deceleration. This value will also affect
mid-corner performance, with higher values not allowing the differential to
unlock as much, increasing mid-corner understeer.
BMW M HYBRID V8 // USER MANUAL
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