Racing Simulation Tuning Guide

8/19/2019 Racing Simulation Tuning Guide

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Racing Simulator

Tuning GuideFor all your game tuning enjoyment!!

by Vyssion

1RACING SIM TUNING GUIDE - IMAGE LIFTED FROM HTTP://WWW.CARADVICE.COM.AU/

http://www.caradvice.com.au/



Suspension

Front Anti-Roll Bar

Front anti-roll bar settings are increased to do the following:

• Causes outside front tyre to heat more rapidly than inside front tyre

• Provides slightly more heating to the inside rear tyre

• Should induce understeer on most cars. Affects turn-in the most and may improve

grip at the apex

• Earlier front brake locking into turns

• Coupled with a reduced rear anti-roll bar, understeer is strongest at turn

exit

Tyre Pressure

Tyre pressure is increased to do e following:

• Reduce tyre heating and peak temperature

• Reduce rolling resistance

• Reduce contact patch (grip)

• Note that greatest changes will be observed in the middle of the tyre

Spring Rate

Spring rate settings are increased to do the following:

• Reduce suspension travel and motion

• Reduce grip slightly

• Reduce relation response time

• Increase tyre heating and peak temperature

Note that springs only determine how far the suspension will move in relation to the

chassis under a given load; that in turn, affects other components such as dampers and

anti-roll bars. Generally, softer springs will allow the suspension to work better as long as

the car does not bottom out due to aerodynamic or braking forces. Spring rates have a

limited effect on tyre heating and oval tracks may require stiffer springs on one side to

manage the tyre heating.





Slow Bump

Slow bump settings are increased to do the following:

• Increase tyre heating and peak temperature

• Slow suspension motion due to g-forces

• Increase initial grip slightly

• Reduce reaction response time

Note that dampers only determine how fast the suspension will move. In the bump

direction the tyre is being loaded so higher settings will slow the distribution of loading

the other tyres; response of the loaded tyre is a little crisper initially but may lose grip as

the end of travel is reached as the weight is unloaded. Due to this increased tyre loading

however, tyre heating will increase in some cases significantly. Slow bump is a good way

to equalise tyre heating because if does not need to be matches on axles (although it has a

cross corner relationship to slow rebound)

Fast Bump

Fast bump settings are not always needed or even used. Road bump loads are much

more severe than g-force loads and can create enough pressure to blow the damper apart.

For that reason there are pressure valves inside the dampers that pop open at pressures set

by "fast bump". Slow settings are simply orifice sized holes to constrict flow. Fast settings

should be lower than slow settings but how much depends on the track. Too low of a

difference can allow pressures from the fast settings to "override" the soft. Generally a

good starting point is to set the fast bump to 60-70% of the soft bump and note the track

conditions. Hard bumps on a straight may not cost too much time where riding curbing

through turns may require very soft settings to fast bump and rebound.

Slow Rebound

Slow rebound settings are a little more complicated because the weight transfer

actions are somewhat paired to the tyres on the opposite axle differently, depending on

lateral and longitudinal forces. The effects are transitional meaning the effects listed below

will react on the paired corner rather than the corner that is being adjusted.

Slow rebound settings are decreased at the rear to:





• Reduce apex and exit understeer; particularly useful when an entry oversteer

changes to understeer between the apex and exit

Slow rebound settings are decreased at the front to:

• Reduce apex and exit oversteer; particularly useful when an entry understeer

changes to oversteer between the apex and exit

Fast Rebound

Fast rebound settings are similar to fast bump in that not all cars utilise them and

they are more for road shock than g-force loads. Fast settings should be lower than slow

settings once again due to the possibility of overriding the soft ones. As before a good

place to start is at 60-70% of your slow setting.

Packers

Packers provide an extra spring setting with super stiffness; they are to cushion the

end of the suspension travel. The thicker they are, the more progressive they are being

softer at first and then increasing rapidly. Generally, if you run the ride height low,

packers can be your best friend. Typically a ration of 30% packer stack height to rideheight is a good starting reference point. Once you have lowered the car to where it just

clears the track at quarter to half a tank of fuel, if it begins to rub with a full tank, increase

the ratio up to 50%.

Ride Height

Ride height is a key setting that changes the roll centre and suspension geometryand can improve grip through turns. Relative to roll centre the lower the car is the better.

Suspension geometry may not work well with a lowered ride height however. Also

dependent on the effect is the rake angle; the stagger between front and rear heights.

Generally the rear should be about 18-20mm taller than the front. Increasing rake angle on

most cars will improve exit grip under throttle and increase downforce (and drag).





Camber

Camber allows angling the tyre such that it maintains a flat contact patch though out

cornering. As the car rolls through a turn, the physics of the tyre and suspension

movement tend to shift the contact patch forces to the outside of the tyre. Having a

negative camber on a wheel compensates for

this. However, as negative camber is dialled

in to improve lateral grip, it begins to diminish longitudinal grip. Those losses may be

amplified, for example, when the front suspension drops under braking, negative camber

increases. Generally you want a temperature difference of 7-12°C between the inside no

outside of the tyre.

Front Toe In

Front toe in preloads the front tyres to compensate for slip angle grip. Put simply,

the tyre needs some twisting distortion before reaching maximum lateral grip. While

anything but 0° will add to the rolling resistance, the added resistance is minimal at lower

speeds (under 150km/h) with fractional amounts of toe.

Front tyres favour about 0.1-0.2° toe out for most cars. As the tyre steer, the inside

tyre has a slightly reduced turning radius that requires it to steer "faster" than the outside,

hence, toe out.

• Add positive toe to improve front turn in grip particularly on slower tight turns

• Most cars begin to drop performance after 0.5° toe out

• On higher speed tracks toe out may need to approach 0°

Rear Toe In

Rear toe in preloads the tyres to compensate for slip angle grip.While the front tyres

favour toe out, rear tyres favour toe in. The rear tyres point straight ahead while the fronttyres steer so toe in properly preloads the slip angle.

• Rear tyres favour about 0.5-0.15° toe out

• Add negative toe to improve rear turn grip on any type of turn.

• Rear toe in is more sensitive than front toe

• Increasing rear toe can help stabilise any transitions to oversteer during light

braking or decelerating.

• On higher speed tracks, rear toe may need to approach 0°





Caster Angle

Caster allows the front tyre to change camber proportionally as they are steered.

Even better, the camber changes more directly follow the changes to the contact patch.

Caster also shifts weight from the outside front tyre to the inside front tyre.

Because caster requires the tyres to be steered to have an effect, the more of a

steering angle you have during a turn, the more effecting caster is. However, on tracks

that have mostly high speed sweepers and fast straights, caster will make the car twitchy

and less stable.

After getting camber right, begin adding caster in increments of 1° at a time while

adding +0.5° (not negative!) camber to each front tyre. This may allow the contact patch to

be optimised for both braking and turning.

Rear Anti-Roll Bar

Rear anti-roll bar settings are increased to do the following:

• Causes outside rear tyre to heat more quickly than inside front tyre

• Provides slightly more heating to the inside front tyre

• Should induce oversteer on most cars and may improve front grip at apex of

corners

• Earlier rear brake locking into turns which can be managed on downshifts with

settings to engine braking

• Coupled with reduced front anti-roll bar settings, added oversteer is strongest at

turn exit.

• May require lighter exit throttle application.

Note that this works well with increasing differential pump and differential power

settings





Aerodynamics

Aerodynamic settings will only gain decent efficiency at speeds above

approximately 100km/h. Higher downforce will increase turn speeds on turns above

160km/h at the expense of drag. If the track has top speeds above 220km/h, the majority

of the time, a lower downforce setting will be faster. You'll have to evaluate the segments

where turns above 200km/h and the subsequently following short straights will benefit

from increased downforce, then weigh those benefits against the reduced speeds on the

longer and therefore faster ones. Higher downforce settings make the car easier to drive

but may impact it's top end speed.

Unless the car is poorly balanced the front setting should generally be in the same ratio as

the rear. That is, if there are 3 settings at the front, and 15 in the rear, a 2 in the front will

work best with a 6-10 at the rear. If the car is not balanced, wings are a last resort; look at

other suspension or balance settings first.





Brakes

Brake Bias

Brake bias allows dialling the ratio between the front and the rear brakes. Simple

enough, but brakes are quite complex. Usually, brakes have the most friction when they

are warmed already (not too hot). Front and rear brakes heat and cool at different rates.

The intent of brake bias is to balance the braking forces between front and rear so that one

brake pair is not overheating too much whilst the other mains cool. Brake disk thickness,

brake ducting and engine braking all play a part in braking.

Brake Duct Size

Brake duct size determines the air cooling to the front brakes. Too much airflow and

the brakes will be too cool on initial application. Nt enough and they fade. Brake ducts

also increase drag and reduce downforce by introducing air underneath the car.

Brake Pressure

Brake pressure sets the sensitivity of the pedal. It acts as a multiplier to the axiscontrol rate. That is, a higher pressure means more braking pressure is applied to the disks

for a smaller displacement of the pedal.

Brake Disk Thickness

Disk thickness affects how quickly the brake will hear and cool. Thicker is more

material which heats and cools slowly and has more mass. Balancing the braketemperatures between the front and rear is essential.

When the brake temperatures are too high, start with opening the brake ducts. If

that cools the brakes too much, then select thicker rotors.





Engine

Rev Limit

The rev limit may have some dire consequences if it is set too high depending on the

car's ability to withstand abuse. You may be able to constrain your foot, but sometimes

downshifts will push the engine right to the rev limit. As such, it is important to log how

the engine revs around a circuit and set a limit that looks after the cars engine whilst not

inhibiting the driver's speed.

Torque Split F:R

Torque split is only relevant in all wheel drive cars. This sets the virtual centredifferential rate of torque split to the front and rear axles. Under acceleration, if the car

under steers, shift the torque bias to the rear. If it over steers, shift it to the front.

Boost Mapping

Boost simply adds or subtracts power in most games. More power may shorten

engine life and consume for fuel however. Of course in real life, this is much morecomplex and boost mapping is a key aspect of car tuning.

Radiator Size

Radiator size determines general engine temperatures including oil. You should

have a record somewhere which specifies at what temperature peak power is generated.

Note that larger radiators will increase aerodynamic drag.

Engine Brake Map

This is in essence like adding or subtracting engine braking to the drive wheels. This

can be a very effective way to help the driver to control the cars balance under braking. It

takes a feel and no two drivers seem to want identical settings.





Gearing Ratios

If the engine is reaching peak RPM before the end of the longest straight, the ratio

needs to be lowered. If the engine is below peak RPM it could be due to wrong gearing of

the drop in power within the “over-rev" zone. Ideally, you want the RPM to match

somewhere between where torque and horsepower falls off. Use the final ratio setting to

adjust top gear only if you can't get the ratio where you need it to be in top gear.

Next set your first gear to as low of a ratio as the track allows; at the slowest point

on the track the engine should be at about 11:00 on the tach needle. This is especially true

with higher powered cars as the available wheel torque is probably enough to exceed grip.

With the top and bottom gears set, space the remaining gears equally between them.

Differential Pump

Differential pump is the distance of radial slippage between the left and right drive

wheels before the torque transmitted to them is split 50/50 in effect making them both

rotate momentarily at the same rate. It can add more grip to combat wheel spin but creates

a binding that is not transmitted back to the driver, simply scrubbing on tighter turns.

Nothing is free.

Differential Power

Differential power is more of how the torque affects understeer/oversteer than

anything else. Increasing differential power tends to increase the propensity to travel

straight ahead under power, that is, understeer. This is actually a good thing if the car

tends to oversteer under power as it balances out.

Differential Coast

Differential coast does the same thing as differential power does except it only does

it during engine braking or regular braking, hence adding understeer. The term "coast" is

a little misleading; it should perhaps be referred to as "deceleration". On tracks where the

rear end seems to want to swap with the front, increasing the coast setting can solve some

of the trailing throttle oversteer issues.





Preload

Preload is kind of the jack of all trades when it comes to the differential. By

increasing the friction between the left and right drive wheels when they rotate at

different speeds. It is the true "coast" factor but it works a little differently.





Chassis

Weight Distribution Longitudinal Front:Rear

Longitudinal weight distribution is an extremely beneficial way to balance the load

on the tyres. Generally, more of the cars weight over a particular tyre, the more grip that

tyre has; but it also alters tyre temperature. Shifting distribution can be used to equalise

tyre temperatures as well as managing some understeer/oversteer. The key is to use is

setting in moderation.

Weight Distribution Lateral Left:Right

Lateral weight distribution is almost mandatory on oval race tracks. Sifting weight

to the inside tyres may be the only way they will reach temperature. It can also be used on

normal road courses where one direction is favoured over the other, particularly if the

tyres no one side are not reaching optimum temperature.

Wedge

Wedge is a type of cross-corner applied bias. If the right front and left rear were onepair, and the left front and right rear were another, one turn of wedge wild move 1-5% foe

the weight from one pair to the other.

Steering Lock

Steering lock is the distance the tyres can steer before hitting the steering stops. This

can be tuned to give different amounts of rotation to lock out the wheels or to fine tunesensitivity.





Third Spring

Conventional suspension systems lack isolation of lateral and longitudinal forces

from tuneable controls. That was a key reason why active suspensions were first designed

and installed on Formula 1 cars. After active suspensions were banned, third spring

systems were developed to add some level of isolation for tuning response to lateral and

longitudinal g-forces separately.

The third spring directly couples both corners on an axle similar to an anti- roll bar.

Spring and damper forces of the conventional and third spring components still have

overlapping effects however the geometry of each system tends to allow for some

independencies.

Third spring systems work mostly on longitudinal forces; the stiffer they are the less

the suspension squats reducing camber action.

Remember that similar rules apply to third spring bump and rebound settings as to

conventional ones.

Spring Rate (Third Spring)

Third spring rate settings are increased to do the following:

• Reduce suspension travel/motion mostly under braking or acceptation.

• This reduces unnecessary camber changed which allows more camber than whenin a detached state

• Increase braking grip

• Reduce reaction response time

• In the real world, suspension geometry will affect the ratio of longitudinal to

lateral overlap.

• Therefore increases to these springs will have the me effect as increasing spring

rates of the conventional springs at 1/3rd the rate.

• This is how they differ; with the conventional spring, an increase of 1 "rate" would

reduce front grip, yet on the third spring, 2/3rd will increase front grip while 1/3rd will

reduce it

Slow Bump (Third Spring)

Third spring slow bump settings are increased to do the following:

• Increase tyre heating and peak temperature under braking and acceleration






• Allow deeper braking into turn (front only)

• Allow earlier application of throttle through turn exits (driven wheel adjustments

only)

• Whilst the springs have a larger effect on the longitudinal forces, dampers tend to

affect the suspension velocities equally for lateral and longitudinal forces.

Slow Rebound (Third Spring)

Third spring slow rebound settings are increased to do the following:

• Increase tyre heating and peak temperature under braking and acceleration


• Allow earlier throttle application through turn exit (front only)

Fast Bump (Third Spring)

Third spring fast bump settings are decreased to do the following:

• Allow faster motion over bumps and curbing

• Reduces "float" over curbing

If the car is bottoming out over bumps that run across the track, increase the third

spring fast bump

Increase the front third spring fast bump if the rear feels loose over curbing

Increase the rear third spring fast bump if the front feels loose over curbing

Fast Rebound (Third Spring)

Third spring fast rebound settings are decreased to do the following:

• Allows faster motion over bumps and curbing

• Reduces "float" over curbing

Increase the rear third spring fast rebound when the front loses grip entering a turn

with road bumps

Increase the front third spring fast rebound when the rear loses grip exiting a turn

with road bumps





Packers (Third Spring)

Third spring packers can be increased to assist conventional packers to prevent

bottoming to from a low ride height.

Add third spring packers to the front if the car is bottoming out under braking or if

the front is bottoming out from high speed banking.

Add third spring packers to the rear if the car is bottoming out under acceleration or

if the rear is bottoming out on high speed banking.



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