This guide is intended to provide general advice about car setup, suspension geometry, adjusting your vehicle for best performance and also general tips and tricks related to attending track events.
The particular needs of you as a driver and how you setup your car will vary depending on the type of vehicle and different types of event you attend, along with your specific driving style and skillset.
As such, this guide is to be considered as a general baseline and does not take into account every possible circumstance. Sometimes this guide may not have the exact solution for a setup situation, that is the nature of cars.
Don't forget, there is so much more to vehicle setup than just this guide. So please consider this a stepping stone for your thinking around setup for your car.
Nonetheless, feel free to share your feedback via the contact option in the settings screen should you wish to see something added to this guide.
Enjoy!
For most drivers the key aim is to maximise the grip level available at all four tyres. This, in it's simplest form, is generally known as 'mechanical grip'.
The key components of a car setup that influence mechanical grip are the tyre selection, the tyre temperature and pressures, and wheel cambers and toe. Altering these variables are at the immediate control of the driver/engineer and are one of the first methods of adjustment for dialing in your car setup.
However, no track is ever just smooth and straight, and as such, the vehicles suspension helps influence that mechanical grip when the car is loaded due to motion be it braking, acceleration, or through a turn. This transient nature of handling means that suspension components such as springs, anti-roll bars and dampers are fundamental to grip and critical in controlling ride, roll and pitch.
This mechanical grip also must be met with balance. In particular, front to rear balance so as to influence over-steer\/under-steer. Front axle grip and rear axle grip may be adjusted independently to suit the intentions of the driver and the balance of the vehicle. The intended or target balance will depend on many factors including the track, conditions, laptime, tyre life etc.
Overall, the ideal target is to increase overall grip available at each wheel as best as possible, over the full length of a lap, and with the end goal of the fastest lap time.
Your tyres are the only thing in contact with the road surface. As such, it's essential that you manage them to maximise your vehicles grip and balance during all the key transients of track performance.
There are two main variables at work with tyres that influences their performance, temperature and pressure. There are also two main types or compounds of tyre, a general road tyre and a dedicated track tyre.
Aggressive driving increases the heat generated by the tyres which is as a result of the friction between the rubber and the road surface. As the temperature increases, so to does the pressure. These two variables can influence one another in a cycle, more pressure = more heat = more pressure. As such, it is important to:
1. Monitor your tyre temperature
2. Target and maintain a consistent temperature across the face/surface of your tyre
3. Avoid severe overheating of the tyre caused by excess pressure or over driving.
Similarly, the tyre pressure influences the surface patch in contact with the road, and also the stiffness of the tyre and it's sidewall.
Ideal pressure is perhaps more critical than ideal temperature, in so far as once you have achieved and maintained a 'perfect' pressure, your temperatures are used simply to validate your findings.
There is no one ideal pressure. The target hot pressure of your tyre depends on the vehicle, weight, tyre compound, track & weather, and even the drivers preference. A cold tyre will be initially 'under pressured', but that will also help to bring it up to temperature and pressure more quickly. In general a cold tyre will build pressure within a lap or two to achieve the ideal 'hot' pressure.
Tyre pressures will need to be checked and recorded as quickly as possible after each on track session when still up to temperature and pressure, and adjusted as necessary.
A tyre that is under inflated will allow the sidewalls to flex too much which can cause muted handling, poor turn-in and possible damage to the tyre with excess shoulder wear when cornering. A colder mid point surface temperature may also be indicative of this situation.
A tyre that is over inflated will present excessive wear around the centre of the tyre tread, and a high mid point surface temperature would indicate this case. This can also lead to reduced grip levels and a firmer ride.
Prior to driving on circuit, you will want to set your tyre pressures to approximately 4 psi below the target hot pressures. This way, during the first track session, the temperatures and pressures will increase and ideally end up at the ideal pressure.
After the session, check the pressures and adjust to your target pressure as mentioned in the segment on pressures above. After each subsequent session, the tyres will begin to maintain a more consistent pressure and require less adjustments, however continue to check and adjust again if necessary.
See the further section below on how to use tyre pressures to influence vehicle balance and alter under-steer and over-steer.
Knowing where your tyre temperatures and pressures are currently at is one thing, but knowing what the ideal pressure is, and achieving said ideal pressure, is what you are really trying to achieve.
This always starts with a baseline pressure for the beginning of your day or event. Your baseline comes from experience.
For those amatuers with no prior data from which to gauge a target hot tyre pressure, the following table is a general guideline for where you can target your tyres (+/-2psi).
Weight (KG) | Hot Pressure (psi) |
---|---|
Under 1000kg | 28 psi |
1000kg to 1500kg | 32 psi |
1500kg and over | 36 psi |
Immediately after each hot track session, when tyres are still at temp, you need to get a datum on each tyres pressure so that you know where they are at, but importantly you also need to record their temperatures, so you can read how they are performing at the current pressure. To do so, we need to use a tyre pyrometer.
An infrared temperature probe is insufficient in this case, a proper pyrometer probe is the best method for measuring the tyres workload and temperature status.
The probe can be inserted into the tyre to measure the temperature below the surface where a more accurate reading can be taken.
You will need to measure and record three temperature readings across the contact surface of each tyre. One reading is taken at the centre of the tyre, and then one reading taken front each of the edges, the outside edge and the inside edge.
In an ideal world, there will be a small, but consistent/linear variance between each reading. At most around 15°C between hottest and coldest.
Analysis of the temperature readings can then help to indicate whether a change in pressure may be required. The general summary is:
Temperature Result | Remedy |
---|---|
Centre hotter than edges | Reduce Pressure |
Edge hotter than centre | Increase Pressure |
Inside edge hottest | Reduce negative camber |
Outside edge hottest | Increase negative camber |
All temps very low | Pressure too high |
All temps very high | Pressures too low |
Understeer is a term to describe a car that won't turn in, or that pushes forward and runs wide of a corner.
To Alleviate Understeer:
• Soften front anti-roll bar or stiffen rear
• Soften front dampers or stiffen rear dampers
• Soften front springs or stiffen rear springs
• Increase front negative camber
• Increase front wheel/tyre width
• Raise front tire pressure or lower rear tire pressure
• Lower front axle ride height or raise rear
• Increase front wing downforce
• Reduce front toe-in
• Brake earlier and smoother
• Reduce corner entry speed
• Reduce throttle application mid corner
Oversteer is a term to describe a car that turns too much, feels loose, or slides out at the rear.
To Alleviate Oversteer:
• Stiffen front anti-roll bar or soften rear
• Stiffen front dampers or soften rear dampers
• Stiffen front springs or soften rear springs
• Decrease front negative camber
• Increase rear wheel/tyre width
• Lower front tire pressure or raise rear tire pressure
• Raise front axle ride height or lower rear
• Increase rear wing downforce
• Brake earlier and smoother
• Reduce corner entry speed
• Reduce throttle application mid corner
• Remove weight from rear of vehicle
Instability of a car under any condition can have a significant impact on driver confidence. This can severely hinder laptimes purely due to the psychological effects, but also due to the mechanical impact of the unstable cars performance and grip.
Usually something is 'broken' to cause the instability, however sometimes it can be caused by setup.
• Poorly balanced aerodynamic downforce
• Mechanical fault with chassis or suspension
• Worn or faulty driveline, transmission, diff or driveshafts.
• Excessive front axle toe-in or toe-out
• Excessive toe-out at the rear axle
• Mechanical fault such as poorly maintained caliper
• Excess forward or rearward brake bias
• Damaged or flatspotted tyres
• Very excessive aerodynamic downforce
• Insufficient downforce, or high levels of lift
• Firm suspension geometry caused by over inflated tyres or stiff dampers
The general school of thought when driving on a wet track is to slightly increase tyre pressures to better resist aquaplaning. Given the likely reduction in the ability for the rubber to gain heat, the increased pressure should help to compensate for that also.
Suspension geometry overall can be run in a softer configuration. Springs & dampers, along with anti-roll bars can all be softened to aid with traction, improve driver control at the limit, make the car more progressive and easier to control. Similarly, as our dry camber and toe settings previously relied on the higher grip to make them effective, the reduced stiffness in the wet means the same camber levels at the lower grip levels may still be appropriate.
Wet tracks obviously reduce grip levels, this most significantly impacts braking and cornering, but less so acceleration. As such, top speeds are not reduced as much as the braking distance will increase.
Brake bias will be altered as forward weight transfer will be less prevalent in the rain, more rearward braking should be used to compensate for this
Avoid water ingress by blocking off ducts, particularly those that may feed to the driver.
Wet weather usually also means colder temperatures. You can usually block of some of the front facing vents or openings for radiators to improve aero efficiency and reduce over-cooling.
Consider ways to keep the cabin and engine bay clean and dry. Mop up excess water after each on track session, and wipe the driver foot-well of water that the driver may have brought in.
A clean windscreen and visor are critical where a wet track can compromise visibility, give everything a good clean.
Critical components that you want to be sure will not get wet include your electrical components and engine computer, and intake air system feeding your engine bay.
You may want to consider using WD-40 to keep water out of electrical components however use sparingly and be mindful that there is a chance it will cause more damage than good.
Amateur drivers can often get caught into the trap of making ill-informed setup changes to their vehicle in the endless chase for faster laptimes and better car balance. Following are a list of the most frequently seen in this type of situation for you to keep in mind.
The most common and most significant mistake a driver may make is not properly monitoring the tyres, or failing to make observations on how the tyres are performing based on the data available. It is one of the key indicators as to what is
happening with the car. Regular tyre temperature/pressure readings throughout a day are very important - see tyres sections above for more.
Many people know what 'coilovers' they are running, but may not know their spring rates, anti-roll bar rate, or chassis stiffness. Without knowing the car, how can educated judgements on handling or setup changes be made?
Changes to the vehicles setup or geometry must come with a plan, and in most cases involve one change at a time. A common mistake for less experienced drivers is to make too many changes all at once without understanding how each one may effect the vehicles characteristics. Think 'if I make change X, I should see outcome Y'. Making one change at a time is advisable to best evaluate the impact of the change.
Not every handling or balance characteristic is caused by one adjustment. Some symptoms may have multiple causes and sometimes multiple components compound a symptom. Sometimes multiple issues can occur and interfere with one another. Don't overly focus on one component to remedy an issue, if you aren't seeing an improvement. Consider alternative changes that may also come into play. For example, spending a day playing with damper stiffness to remedy an oversteer issue, when in fact your tyres are overheating and over-pressured.
Never to be forgotten are the basics. Here is a list of all the things that need to be kept in mind and tended to before any on track event.
• Engine oil & oil filter checked
• Brake fluid checked or flushed
• Transmission Oil checked
• Brake Pads & Rotors checked
• Tyres checked for wear and pressure
• Fuel topped up
• Coolant level checked
• Wheel nuts torqued to spec
• No Steering Wheel play
• All Suspension bolts checked and tight
• Shock bump and rebound settings set to baseline
• Suspension and anti-roll bars lubricated
• Check all CV boots in good condition
• Brake, clutch and throttle pedal movements are correct
• Monitor/charge battery level
• Spark plugs checked / gapped
• Fuel and oil lines checked
• Air filter/intake cleaned
• Vehicle Cleaned and Washed
• Tow vehicle / trailer Lights checked
Of course no track event will succeed unless the car and driver are looked after throughout the event. Ensure sufficient equipment is packed to keep both the driver and vehicle comfortable and sustained and spare gear if something needs tending to.
• Plenty of food and water
• Suitable Helmet
• Necessary racing License / Documentation
• Spare change of clothes
• Driving Gloves/Shoes/Suit
• Torque Wrench
• Basic tool kit
• Breaker Bar
• Toolbox / sockets / spanners
• Jack & axle stands
• Alignment tools
• Tyre pressure gauge
• Duct tape / cable ties
• Wheel Chocks
• Pens & Markers
• WD-40
• Fuel cans & funnel
• Jump Starter
• Tie Down Straps
• Windex
• Cleaning Rags/Paper Towels
• Umbrella
• Folding Chairs
• Stopwatch
• Clipboard
• Spare engine oil and coolant