Formula 0.5 Car Setup Guide
Posted: Mon Dec 14, 2009 9:12 pm
The Formula 0.5 Car Setup Guide
Although the following guide is written with the Formula 0.5 cars in mind, I will touch on the physics and methods involved in car setups, so most of the points below should also apply to any other cars.
This guide is NOT meant to set your car up for you. It is to assist YOU to setup your car for yourself.
Rather than just explain the effect of any given change, I’ve tried to explain WHY this effect happens, and what other options can create a similar effect.
I have tried to simplify as much as possible for two reasons….
1. So as not to unnecessarily confuse anyone.
2. Because I am not a professor of physics
If you feel that any of the below is incorrect (I make no guarantees that it isn’t), please let me know and I will attempt to rectify it.
However, I’m not interested in hearing that something’s wrong because you THINK it is, or even because you KNOW it is, or because your Uncle Phil does things differently.
If you feel something is incorrect, find a trustworthy reference indicating so(Wikipedia, The National Auto Club, etc) and include a link for me.
I don’t feel like spending hours of my time performing research based on someone else’s (possibly incorrect) opinion.
An Overview
The Basics
Firstly, it must be said that a car has a certain amount of grip…short of adding downforce or changing tyres you cannot increase the total amount of grip a car has. What you are trying to do with your car setup is distribute this grip to the right wheel, at the right time.
In order to do this, you must first understand what grip is….
Grip (in race car terms) is the result of downward force being applied to the wheel, forcing the tyre onto the racing surface. The more weight on a wheel, the more grip it has.
As an example…when you accelerate smoothly, the car’s weight balance shifts towards the rear of the car. This reduces the weight on the front wheels, so understeer is induced. The inverse happens when braking smoothly.
Your goal is to find the balance between oversteer and understeer in every situation by fine-tuning the suspension….Be it accelerating out of a corner, braking into a corner, coasting through a corner, etc.
A More In-Depth Look at Balance
Almost all adjustments in a car’s setup are related to at least one or two other settings.
For example….The effect of the brake balance setting is governed by the suspension setup. If the rear wheels are locking up under braking, you COULD move the brake balance forwards to reduce braking force at the rear end of the car. OR you could stiffen the front slow bump and soften the rear slow rebound. BOTH would prevent the rear wheels locking up, but they are achieving this in different ways.
By moving the brake balance forwards, you are simply reducing the amount of braking the rear wheels are doing to suit the amount of grip they have. Whereas by softening the rear slow rebound and stiffening the front slow bump you are preventing the weight of the car from moving forwards and keeping more weight on the rear wheels, thereby increasing the amount of grip the rear wheels have under deceleration to suit the amount of braking you’re asking them to do.
A simpler way of looking at it would be this….
One option is changing the amount of work each wheel has to do, to suit how much grip it has.
The other option is changing the amount of grip each wheel has, to suit how much work it has to do.
You will see the word “balance” a lot in this guide, as I feel it is the key foundation of car setups.
Newton once said, “For each and every action, there is an equal and opposite reaction”….smart dude.
Every change you make to your car, has a negative effect as well as a positive effect.
As mentioned earlier, you’re simply distributing the weight balance of the car…so when you allow the weight to move to the rear, you’re ALSO allowing weight to move away from the front.
If you give yourself more front-end grip on corner entry, you’re also sacrificing rear-end grip on corner entry.
If you remove oversteer on corner exit, you’re also adding understeer on corner exit.
The secret is to find the balance between all of these and more….
No one said setting up a car would be easy
A LOOK AT EACH SETTING
Downforce
As mentioned earlier, aside from changing tyres, the only way to add grip to ALL wheels is by increasing the aerodynamic downforce. But of course, this also increases drag on the car resulting in lower speeds on the straights.
The choice of how much downforce to apply for any given track is based on the layout of the track.
Do a few laps, and see how much time you’re spending off the throttle, as opposed to how much time you’re spending with your foot flat to the floor.
Also, it can be useful to compare your sector times to other drivers. If you’re slightly quicker in sectors 1 & 3, but drastically slower in sector 2 (where there happens to be a long straight) this should tell you that reducing your total downforce would be a good idea.
As always, when applying downforce you must think of the balance between oversteer and understeer. More front downforce will increase the grip of the front wheels, while more rear downforce will increase the grip of the rear wheels.
Brake Balance
The brake balance setting adjusts the application of the braking force between the front and rear wheels. THIS IS ALL IT DOES.
If your car feels perfect everywhere EXCEPT under heavy braking, this is the setting to look at. However, if your car has a couple of areas that are in need of improvement then you may find that this isn’t the right setting to be adjusting just yet.
For example….If your car is a bit loose under heavy braking, but is ALSO a bit loose under light braking, then you should probably be looking at increasing the unloaded grip at the rear wheels by adjusting the suspension.
Springs
The Formula 0.5 mod has the spring rate locked for simplicity’s sake. However I will briefly cover springs in order to provide a better understanding of the entire suspension setup. Without understanding what the springs do, one can’t hope to successfully understand dampers, which I will describe shortly.
The springs are what the weight of the car rides on. They are also what the car balances on.
I specify these two aspects separately because they are two very different roles that the springs serve.
When thinking about suspension set up, one must differentiate between the ride (how the car behaves over bumps and imperfections in the racing surface) and the balance (how the weight of the car shifts depending on the forces the car is currently under).
BALANCE
As the weight balance of the car shifts, the springs must compress and extend to allow it to happen. The stiffness of the springs sets how much force is required for the weight to shift, and therefore to what degree it shifts. A softer spring rate allows for more weight transfer between the wheels.
If, for example, you were struggling to get the power down out of corners due to excessive oversteer, one solution would be to soften the rear springs allowing more weight to transfer onto the rear wheels. However….given that any adjustment you make to the spring rate affects both the compression AND the extension of the springs, and that it is the force of the springs that push the wheels onto the road when they are unloaded, doing so would reduce the rear end grip under braking.
As with downforce, springs are best considered as a setting to look at when the car handles poorly in MANY situations, as opposed to just A FEW situations.
In the case of fixing one specific problem area, I would advise focusing on the damper adjustments.
RIDE
When a wheel hits a bump in the road, or perhaps a curb, the springs must compress in order to absorb this impact. A stiffer spring rate will result in the spring not compressing much, and the car popping up into the air. Wheels that are in the air, quite unsurprisingly, don’t offer a lot of grip. However, it is also the spring that pushes the wheel back down to the road surface again, so softer springs take longer to apply the weight back down onto the tyre while unloaded. Finding a happy medium that allows you to take minor bumps without losing too much grip is the key.
Dampers
Dampers adjust the rate at which the springs can compress or extend.
Bump damping adjusts the rate at which the springs can compress, while Rebound damping adjusts the rate at which the springs can extend.
In “balance” terms….the harder the damper setting, the slower the weight balance of the car changes, and therefore the less it changes.
In “ride” terms….the harder the damper settings, the less effectively the spring will be able to absorb any impact. With softer dampers however, the car will want to continue bouncing after any kind of impact, as it is the damping which prevents this “pogo” effect.
In the Formula 0.5 mod the fast damping has been set to a safe default and locked off, so you have far less to adjust. But some mods allow for independent adjustment of the fast damping, and slow damping.
This ability to independently adjust slow and fast damping makes setups easier to understand, because fast damping affects the ride over bumps, while slow damping affects weight transfer.
Here are a couple of problems that can be specifically targeted with damper adjustments, and an explanation as to why the specified solution will solve the problem in question.
Oversteer on corner entry, while braking ….
Stiffening the front slow bump will prevent the weight of the car from transferring forwards (as it is inclined to do while decelerating). By inhibiting the weight from moving forwards, you are keeping more weight on the rear wheels, and therefore improving their grip. BUT (there’s always a but) by inhibiting the weight from moving onto the front wheels, you will also be reducing the amount of grip they have available, so don’t overdo it or you’ll start understeering into corners.
Another option, would be to soften the rear slow rebound. Remember that one of the main jobs of a damper is to impede the springs from extending, so softening the rear slow rebound will better allow the springs to force the rear wheels onto the road while the weight shifts forwards.
If you were understeering into corners, then increasing the rear slow rebound would reduce rear-end grip, and therefore improve your turn-in.
Understeer while accelerating out of corners….
This is caused by the front wheels not having enough grip while you’re accelerating. So let’s give them some more…
Again, you have two options:
You could soften the front slow rebound, to better allow the springs to push those front wheels down onto the tarmac.
Or you could prevent the weight from moving towards the back of the car by stiffening the rear slow bump.
By now, I hope you have a good understanding of how to control the weight balance using the dampers.
As a side note…the Formula 0.5 mod has the front independent dampers locked off to safe defaults. However, adjusting the Front-Third Damper settings (found under the “advanced” tab) will have the same effect as adjusting the front left and right dampers simultaneously.
Anti-Roll Bars
NB: Take with a grain of sand...this section is not totally accurate
Anti-roll bars work to prevent the body of the car from rolling. Generally body roll is considered to be a bad thing in a race car, but don’t be too quick to eliminate it altogether. It is the act of the body rolling that transfers weight onto the wheels that need it the most, the outside wheels.
The disadvantage to having a lot of body roll, comes when you need to change the direction of the car rapidly, such as very sharp corners, or S-bends.
When taking a right-left S-bend for example, if your car has too much body-roll all the weight will roll to the left hand side of the car as you drive through the right hand corner. Upon trying to turn into the left hand corner, all the weight will still be on the left wheels and you’ll have very little grip for the left hander. By minimizing this body-roll, the weight will be able to shift back to the right hand wheels much faster.
When adjusted independently, the anti-roll bars can also be used to change the balance of the car between oversteer and understeer.
By softening the front anti-roll bar in relation to the rear, the front end of the car will better be able to shift its weight to the outside front wheel, while the rear remains unchanged. This allows more grip in the front without affecting the rear, and therefore induces oversteer.
The inverse happens when you harden the front anti-roll bar.
Likewise, softening the rear anti-roll bar will better allow the rear-end of the car to transfer its weight to the outside wheel, granting improved lateral grip, while the front remains unchanged. This will induce understeer. Stiffening the rear anti-roll bar will have the opposite effect, and induce oversteer.
Ride Height
When adjusting ride height, the most obvious consideration is ground clearance. If the car’s undertray bottoms out onto the track surface at any point, all the valuable downforce being generated by the car’s aerodynamics is instantly being applied to the undertray rather than the tyres. This will result in a sudden and drastic loss of grip.
However there is more to ride height adjustment than just ground clearance.
Bernoulli's principle states that as a fluid or gas (in this case…air) is accelerated through a small channel, its pressure lowers.
By lowering the car, you are forcing the air to accelerate as it passes between the undertray and the ground. This reduces the air pressure under the car, literally sucking it down onto the track.
This phenomenon is known as “ground effect”.
The positioning of the ground effect can be altered by raising or lowering one end of the car independently of the other. For example, lowering the rear end of the car will add more downforce to the rear without affecting the front end.
Although the following guide is written with the Formula 0.5 cars in mind, I will touch on the physics and methods involved in car setups, so most of the points below should also apply to any other cars.
This guide is NOT meant to set your car up for you. It is to assist YOU to setup your car for yourself.
Rather than just explain the effect of any given change, I’ve tried to explain WHY this effect happens, and what other options can create a similar effect.
I have tried to simplify as much as possible for two reasons….
1. So as not to unnecessarily confuse anyone.
2. Because I am not a professor of physics
If you feel that any of the below is incorrect (I make no guarantees that it isn’t), please let me know and I will attempt to rectify it.
However, I’m not interested in hearing that something’s wrong because you THINK it is, or even because you KNOW it is, or because your Uncle Phil does things differently.
If you feel something is incorrect, find a trustworthy reference indicating so(Wikipedia, The National Auto Club, etc) and include a link for me.
I don’t feel like spending hours of my time performing research based on someone else’s (possibly incorrect) opinion.
An Overview
The Basics
Firstly, it must be said that a car has a certain amount of grip…short of adding downforce or changing tyres you cannot increase the total amount of grip a car has. What you are trying to do with your car setup is distribute this grip to the right wheel, at the right time.
In order to do this, you must first understand what grip is….
Grip (in race car terms) is the result of downward force being applied to the wheel, forcing the tyre onto the racing surface. The more weight on a wheel, the more grip it has.
As an example…when you accelerate smoothly, the car’s weight balance shifts towards the rear of the car. This reduces the weight on the front wheels, so understeer is induced. The inverse happens when braking smoothly.
Your goal is to find the balance between oversteer and understeer in every situation by fine-tuning the suspension….Be it accelerating out of a corner, braking into a corner, coasting through a corner, etc.
A More In-Depth Look at Balance
Almost all adjustments in a car’s setup are related to at least one or two other settings.
For example….The effect of the brake balance setting is governed by the suspension setup. If the rear wheels are locking up under braking, you COULD move the brake balance forwards to reduce braking force at the rear end of the car. OR you could stiffen the front slow bump and soften the rear slow rebound. BOTH would prevent the rear wheels locking up, but they are achieving this in different ways.
By moving the brake balance forwards, you are simply reducing the amount of braking the rear wheels are doing to suit the amount of grip they have. Whereas by softening the rear slow rebound and stiffening the front slow bump you are preventing the weight of the car from moving forwards and keeping more weight on the rear wheels, thereby increasing the amount of grip the rear wheels have under deceleration to suit the amount of braking you’re asking them to do.
A simpler way of looking at it would be this….
One option is changing the amount of work each wheel has to do, to suit how much grip it has.
The other option is changing the amount of grip each wheel has, to suit how much work it has to do.
You will see the word “balance” a lot in this guide, as I feel it is the key foundation of car setups.
Newton once said, “For each and every action, there is an equal and opposite reaction”….smart dude.
Every change you make to your car, has a negative effect as well as a positive effect.
As mentioned earlier, you’re simply distributing the weight balance of the car…so when you allow the weight to move to the rear, you’re ALSO allowing weight to move away from the front.
If you give yourself more front-end grip on corner entry, you’re also sacrificing rear-end grip on corner entry.
If you remove oversteer on corner exit, you’re also adding understeer on corner exit.
The secret is to find the balance between all of these and more….
No one said setting up a car would be easy
A LOOK AT EACH SETTING
Downforce
As mentioned earlier, aside from changing tyres, the only way to add grip to ALL wheels is by increasing the aerodynamic downforce. But of course, this also increases drag on the car resulting in lower speeds on the straights.
The choice of how much downforce to apply for any given track is based on the layout of the track.
Do a few laps, and see how much time you’re spending off the throttle, as opposed to how much time you’re spending with your foot flat to the floor.
Also, it can be useful to compare your sector times to other drivers. If you’re slightly quicker in sectors 1 & 3, but drastically slower in sector 2 (where there happens to be a long straight) this should tell you that reducing your total downforce would be a good idea.
As always, when applying downforce you must think of the balance between oversteer and understeer. More front downforce will increase the grip of the front wheels, while more rear downforce will increase the grip of the rear wheels.
Brake Balance
The brake balance setting adjusts the application of the braking force between the front and rear wheels. THIS IS ALL IT DOES.
If your car feels perfect everywhere EXCEPT under heavy braking, this is the setting to look at. However, if your car has a couple of areas that are in need of improvement then you may find that this isn’t the right setting to be adjusting just yet.
For example….If your car is a bit loose under heavy braking, but is ALSO a bit loose under light braking, then you should probably be looking at increasing the unloaded grip at the rear wheels by adjusting the suspension.
Springs
The Formula 0.5 mod has the spring rate locked for simplicity’s sake. However I will briefly cover springs in order to provide a better understanding of the entire suspension setup. Without understanding what the springs do, one can’t hope to successfully understand dampers, which I will describe shortly.
The springs are what the weight of the car rides on. They are also what the car balances on.
I specify these two aspects separately because they are two very different roles that the springs serve.
When thinking about suspension set up, one must differentiate between the ride (how the car behaves over bumps and imperfections in the racing surface) and the balance (how the weight of the car shifts depending on the forces the car is currently under).
BALANCE
As the weight balance of the car shifts, the springs must compress and extend to allow it to happen. The stiffness of the springs sets how much force is required for the weight to shift, and therefore to what degree it shifts. A softer spring rate allows for more weight transfer between the wheels.
If, for example, you were struggling to get the power down out of corners due to excessive oversteer, one solution would be to soften the rear springs allowing more weight to transfer onto the rear wheels. However….given that any adjustment you make to the spring rate affects both the compression AND the extension of the springs, and that it is the force of the springs that push the wheels onto the road when they are unloaded, doing so would reduce the rear end grip under braking.
As with downforce, springs are best considered as a setting to look at when the car handles poorly in MANY situations, as opposed to just A FEW situations.
In the case of fixing one specific problem area, I would advise focusing on the damper adjustments.
RIDE
When a wheel hits a bump in the road, or perhaps a curb, the springs must compress in order to absorb this impact. A stiffer spring rate will result in the spring not compressing much, and the car popping up into the air. Wheels that are in the air, quite unsurprisingly, don’t offer a lot of grip. However, it is also the spring that pushes the wheel back down to the road surface again, so softer springs take longer to apply the weight back down onto the tyre while unloaded. Finding a happy medium that allows you to take minor bumps without losing too much grip is the key.
Dampers
Dampers adjust the rate at which the springs can compress or extend.
Bump damping adjusts the rate at which the springs can compress, while Rebound damping adjusts the rate at which the springs can extend.
In “balance” terms….the harder the damper setting, the slower the weight balance of the car changes, and therefore the less it changes.
In “ride” terms….the harder the damper settings, the less effectively the spring will be able to absorb any impact. With softer dampers however, the car will want to continue bouncing after any kind of impact, as it is the damping which prevents this “pogo” effect.
In the Formula 0.5 mod the fast damping has been set to a safe default and locked off, so you have far less to adjust. But some mods allow for independent adjustment of the fast damping, and slow damping.
This ability to independently adjust slow and fast damping makes setups easier to understand, because fast damping affects the ride over bumps, while slow damping affects weight transfer.
Here are a couple of problems that can be specifically targeted with damper adjustments, and an explanation as to why the specified solution will solve the problem in question.
Oversteer on corner entry, while braking ….
Stiffening the front slow bump will prevent the weight of the car from transferring forwards (as it is inclined to do while decelerating). By inhibiting the weight from moving forwards, you are keeping more weight on the rear wheels, and therefore improving their grip. BUT (there’s always a but) by inhibiting the weight from moving onto the front wheels, you will also be reducing the amount of grip they have available, so don’t overdo it or you’ll start understeering into corners.
Another option, would be to soften the rear slow rebound. Remember that one of the main jobs of a damper is to impede the springs from extending, so softening the rear slow rebound will better allow the springs to force the rear wheels onto the road while the weight shifts forwards.
If you were understeering into corners, then increasing the rear slow rebound would reduce rear-end grip, and therefore improve your turn-in.
Understeer while accelerating out of corners….
This is caused by the front wheels not having enough grip while you’re accelerating. So let’s give them some more…
Again, you have two options:
You could soften the front slow rebound, to better allow the springs to push those front wheels down onto the tarmac.
Or you could prevent the weight from moving towards the back of the car by stiffening the rear slow bump.
By now, I hope you have a good understanding of how to control the weight balance using the dampers.
As a side note…the Formula 0.5 mod has the front independent dampers locked off to safe defaults. However, adjusting the Front-Third Damper settings (found under the “advanced” tab) will have the same effect as adjusting the front left and right dampers simultaneously.
Anti-Roll Bars
NB: Take with a grain of sand...this section is not totally accurate
Anti-roll bars work to prevent the body of the car from rolling. Generally body roll is considered to be a bad thing in a race car, but don’t be too quick to eliminate it altogether. It is the act of the body rolling that transfers weight onto the wheels that need it the most, the outside wheels.
The disadvantage to having a lot of body roll, comes when you need to change the direction of the car rapidly, such as very sharp corners, or S-bends.
When taking a right-left S-bend for example, if your car has too much body-roll all the weight will roll to the left hand side of the car as you drive through the right hand corner. Upon trying to turn into the left hand corner, all the weight will still be on the left wheels and you’ll have very little grip for the left hander. By minimizing this body-roll, the weight will be able to shift back to the right hand wheels much faster.
When adjusted independently, the anti-roll bars can also be used to change the balance of the car between oversteer and understeer.
By softening the front anti-roll bar in relation to the rear, the front end of the car will better be able to shift its weight to the outside front wheel, while the rear remains unchanged. This allows more grip in the front without affecting the rear, and therefore induces oversteer.
The inverse happens when you harden the front anti-roll bar.
Likewise, softening the rear anti-roll bar will better allow the rear-end of the car to transfer its weight to the outside wheel, granting improved lateral grip, while the front remains unchanged. This will induce understeer. Stiffening the rear anti-roll bar will have the opposite effect, and induce oversteer.
Ride Height
When adjusting ride height, the most obvious consideration is ground clearance. If the car’s undertray bottoms out onto the track surface at any point, all the valuable downforce being generated by the car’s aerodynamics is instantly being applied to the undertray rather than the tyres. This will result in a sudden and drastic loss of grip.
However there is more to ride height adjustment than just ground clearance.
Bernoulli's principle states that as a fluid or gas (in this case…air) is accelerated through a small channel, its pressure lowers.
By lowering the car, you are forcing the air to accelerate as it passes between the undertray and the ground. This reduces the air pressure under the car, literally sucking it down onto the track.
This phenomenon is known as “ground effect”.
The positioning of the ground effect can be altered by raising or lowering one end of the car independently of the other. For example, lowering the rear end of the car will add more downforce to the rear without affecting the front end.