As ever, over the coming months we are going to be hearing a lot about car set-up, but what exactly does it involve?
Finding the perfect set-up for an F1 is an almost impossible task. They consist of thousands of interacting components, a small number of which teams are permitted to tweak and change for each race. Yet when they do so, the effects are felt across the whole car. 'Car set-up' therefore refers to the optimum compromise of all the different elements of the car; harmony is the illusive aim for engineers.
Set-ups differ from track to track because each circuit has its own characteristics, presenting a unique challenge for tyres and aerodynamics. The singular driving style of each driver is also an important factor, which engineers must account for, and no driver set-up will be identical. If the right compromise is found, the driver will feel confident to extract the maximum performance from the car.
On the aerodynamic side, rear wing level and front wing angle can be adjusted, while front and rear ride heights can also be tuned to change the aerodynamic behaviour. Suspension settings such as camber, toe angles and stiffness can also be modified, as can the weight distribution - moved forward and backwards within the permitted FIA limits. Some settings, such as the differential and brake balance, can even be changed by the driver on their steering wheel while on track.
It's rare for drivers to use identical car set-ups and typically this will only be the case if one driver has had limited track running or are struggling with the balance. Bigger parameters such as wing levels and ride heights will be very similar, but smaller details like aero and mechanical balance can differ quite widely depending on their styles.
Hundreds of working hours are spent preparing the car set-up in advance of each race weekend, with the goal of delivering the car to track in optimum shape. A large part of the pre-event work is running simulations, both on the Driver-in-Loop (DiL) simulator and computer simulation, to test and interrogate possible set-ups to determine their potential. With efficient simulation, the team can hit the ground running on Friday and focus on fine-tuning for qualifying and the race, looking at elements like track temperature, wind direction and tyre condition.
Thousands of laps are completed in the virtual world on Mercedes state-of-the-art simulator facility in Brackley, for example, which uses sophisticated lidar-scanned, 3D track maps and detailed virtual models of the car. The simulator drivers try out various set-up options and continue the programme over the Friday of a race weekend, sometimes working through the night, to react to and maximise the learnings gained on track.
Ahead of a race weekend, engineers are also running offline computer simulations, using a racing line file generated from the DiL simulator. Engineers can complete thousands of virtual laps a day using this method because the laps can be run in parallel and at a sped-up pace, whereas the DiL must run in real time.
The computer simulations produce thousands of gigabytes of data and this information is generated into graphs and plots, which are useful for understanding the correct wing levels, ride heights and other parameters over a range of set-ups and conditions. This phenomenal computing power allows the engineers to compare set-up changes side by side, mastering how the car will respond to the smallest of tweaks.
Of course, these simulations can never be 100% accurate, and the quality of the simulation is dependent on the quality of data and how accurately the model represents the physics of the car and tyres. But in a world of limited track testing, these tools are crucial for providing the initial first step in the set-up process: deciding on a direction to enter the race weekend with.
Once the engineers know what base set-up they will be running in Friday's first practice session, it's down to the mechanics and engineers to ensure each car hits the track with the correct settings and components. The sessions on Friday are crucial for finding the right set-up direction to use in qualifying and the race, so it's all about maximising the track time and conditions.
Engineers can change as many parameters as they like on the car, but the more changes they make, the harder it is to understand the effects each change has on the car performance, especially during the live sessions. When changing the parameters, it tends to be tackling one problem with one solution. But there are occasions where multiple changes are required.
Between the sessions is when more substantial set-up changes are made to the cars, to suit the evolving track temperature and conditions. Between five and 10 parameter changes are typically made during the gap between sessions, depending on the progress being made with the car set-up.
In the week leading up to the race weekend, the race engineering group will discuss and decide the run plans for each session. Like pre-season testing, run plans feature a detailed schedule of how many laps need to be completed and what the objectives are for each run.
Some influence on the run plan will come from other departments, who will submit priority items such as new parts to try or specific data to be gathered. The race engineering group then prioritises these items and fits as many as possible into the run plan for each session. The DiL and computer simulations also indicate different areas that need to be included on the run plans.
Every lap in practice generates 60 to 100MB of data, depending on the number of sensors on the car, and these figures multiply by four in the post-processing phase. Mercedes receives live telemetry in just 10 milliseconds to the garage for the trackside engineers to monitor, and in just 30ms to the factories in Brackley and Brixworth at European rounds.
Once the runs are completed, the full data offload takes 20 seconds per lap to generate and be available to the garage and factories. All of this data is analysed both trackside and in the UK to understand the car's strengths and weaknesses. Elements like tyre temperatures, wear and pressures are also monitored, to ensure the team understands if the car is in the right performance window.
At the end of each day, the groups at the track and in the UK debrief, with engineers and the drivers sharing feedback and findings to refine the set-up direction or find a new route. The car set-up tends to differ slightly for qualifying and the race. In qualifying, your priority is to have a more responsive car so more front end is added, at the expense of rear tyre degradation. But in the race, more understeer is required to protect the rear tyres, which wear out the quickest.
Bahrain is an extreme circuit that is hard on the tyres, particularly the rears, owing to the rough track surface, mix of corner types, long straights and heavy braking zones.
Car set-up in Bahrain is focused on low and medium-speed corners because the high-speed turns can be taken easily flat. Mechanical grip is also important, to propel the cars out of the slow corners. This is the opposite to tracks like Silverstone, where high-speed corner performance is the priority.
A specific challenge in Bahrain is the differing conditions in practice. FP1 and FP3 take place in the warm temperatures and sunshine of daytime, but FP2 is run in the cooler twilight temperatures also experienced during qualifying and the race. Temperature and track conditions have a huge impact on the tyres and car handling, so it makes car set-up particularly difficult.
Running in FP1 and FP3 therefore has limited value, so those daylight sessions are typically reserved for working on test items or tyre behaviour. The pressure is then on the FP2 run plan, because the twilight session is the only one to provide representative conditions for qualifying and the race. So, track time must be maximised in this session.
The sand is also a factor in Bahrain, although as we observed in pre-season testing, it doesn't tend to cause much drama for the cars and drivers, nor does it impact lap time too much. The sand does however impact track evolution and cause a reset, so it is preferable not to be the first car out on track in a session.