On the front line: Goings on behind the scenes

What you see on track is just half the story. Engineers and mechanics spend hundreds of hours each race weekend finding the perfect set-up behind the scenes.

In his exclusive column, former McLaren team member Marc Priestley takes a look at exactly what happens in the garage during a racing week.

When Lewis, Sebastian and Kimi etc, return to the pits during practice or qualifying and the car disappears amidst a whirlwind of mechanics, engineers, tyre blankets and cooling fans, just what are they up to? We've all heard commentators talking about the team 'working on set up', but what exactly does that mean?

Here I'll try to explain from the team's point of view what's going on.

Long before the light goes green at the end of pitlane, signifying the beginning of a session, F1 teams have put a plan together in an attempt to choreograph proceedings. Upon arrival at each Grand Prix, drivers meet with their respective engineers, who've already discussed potential options with strategists, aerodynamacists and management, and will go through what's been learnt since the last event. Countless people in various departments will have been trawling through gigabytes of data, simulation results, wind tunnel results, findings from the cars themselves as well as evaluating any potential upgrades that might be available. The race engineers will be armed with a summary of this information, how it may be applied over the race weekend and it's potential advantages in various situations, ie. qualifying, race, different weather conditions.

On Thursday afternoon each driver, together with their engineering teams, will normally walk the track. The purpose of which is not to learn which way it goes, but to study in close detail each lump and bump in braking zones, any aggressive curbs to stay away from and the ones which can be used to gain advantage, surface changes, positions of grid slots, safety car control lines, pit entry and exit, pitstop box position, DRS trigger and activation zones, overtaking opportunities, optimum KERS deployment zones as well as a myriad of other circuit specific details. Driving for hours in an F1 simulator is one thing, and they are incredibly accurate, but there's no substitute for seeing the track in it's current state with your own eyes!

Paul di Resta walks the track on Thursday (© Sahara Force India F1 Team).

With the walk complete and notes taken, an engineering meeting will normally take place with all necessary parties. That includes the drivers, race engineers and assistants, control systems engineers, team management, chief mechanic, Pirelli engineers, engine system engineers, aero engineers, strategists and anyone else considered relevant. The purpose is to discuss what options in each area of the car and team are available for each driver over the weekend. 

Following this and after more detailed discussion between driver and engineer, a run plan is produced outlining the proposed course of events during FP1 and FP2, this will then be communicated to each set of mechanics. It will set out initial timings for each run, how many laps each run will consist of and the envisaged changes to the car in between those runs. 

Run plans vary, but may consist of an installation lap early in FP1, followed by two runs later on different tyre options. Simulation work and previous data will have given engineers a good idea of the required changes to the car to adapt to the different tyre compounds. If a driver has a good balance between understeer and oversteer on the soft tyre there may be a change to aero levels, roll stiffness or differential locking etc. to achieve that same balance when switching to a harder tyre compound. The same may apply when running different fuel levels.

Any run plan has to be adaptable of course, if a driver comes in after his first run reporting that things are definitely not as they'd expected, set up changes and an extra run may be required to find the right car balance before meaningful tyre evaluation can be carried out.

So on Friday morning, with driver strapped in, radio checks complete and a sea of people surrounding the car, the race engineer monitors track activity using the GPS tracking system available to all teams. Even though the pit lane may be open and it's only an install lap, if it's possible to find a decent gap on the circuit, that's always preferable.

Engineers study the live data on the pit wall (© Williams, LAT Photographic).

With the car sat just off the floor on short stands and tyres wrapped in heated blankets, the number one mechanic in charge of the car awaits a signal from his race engineer to send it out of the garage. He, in turn signals to the rest of his team that it's time to go, blankets are removed, the car's lowered to the ground and the driver's waved out into the pit lane.

Whenever a car returns to the pits in the session, the team's ready to meet it, with brake fans if necessary, and reverse it into the garage.

From there mechanics carry out their standard procedures: car back on stands, tyre blankets back on, any cooling fans as required, refuel and have a good look over the car whilst driver and engineer discuss the run on the radio. 

As the driver describes the car's handling characteristics, the race engineer will hopefully be able to suggest options for improvement in certain areas. This can include mechanical changes, things like anti roll bar stiffness, torsion bar or spring stiffness, revised damper settings or adjustments to the car's ride height. It's not unheard of to adjust ride heights by as little as half a millimeter as part of a set up change. Aero levels can be trimmed, mostly with front and rear wing settings, tyre pressure adjustments too can have a profound effect on their performance over a run and are constantly being monitored and corrected. 

As well as the mechanical changes carried out by the technicians, data sent back from the car to the pits is studied and analysed to look for improvements in each area. This can include giving feedback directly to the driver on his technique. Data is compared with that driver's quickest laps, but also with data from the other car to find areas where each can improve. It may be that one driver carries more speed into a particular corner, but his exit suffers as a result and the data may be able to show that the quicker way is a slower, more controlled entry, allowing a slightly different line and earlier onto the power at exit. We might be talking 3 or 4 kph difference or less than half a meter of track position at turn in or braking points, but that's how closely it's all studied.

Engineers make constant tweaks to the set-up (© Red Bull, Getty Images).

The car's electronic systems controlling things like gearbox, engine, KERS, DRS and differential operation are also constantly tweaked as part of set up changes. Things like the amount of diff locking or engine braking can be optimised at different levels for each corner and even parts of each corner. These changes are performed by systems engineers, usually stood at the side of the garage, with computers connected to the car via the 'umbilical', a large cable plugged in every time the car's in the garage. This allows fast, secure download of onboard data from the car, and digital code to be uploaded and embedded into the onboard management control systems when changes are required.

All of these changes happen simultaneously and can take no more than a couple of minutes to complete. Mechanics and systems guys inform the race engineer when the car's ready and once again everyone waits, poised for the next run.

Gains in laptime are all about finding tiny increments all around the lap and most set up changes end up with a compromise, or trade off, against another part of the car's characteristics. Often, the car will come back after it's run, having made all of the changes, only for mechanics and so on to be asked to go back on everything they've done in order to run another comparison with the original set up, sounds frustrating to undo all of that work, but that's the job and if it means a quick car at the end of the session, nobody minds.  

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Marc Priestley (@f1elvis) has a wealth of experience having worked at McLaren between 1999 and 2009 as a race mechanic and member of the team's pit crew. Marc has worked with drivers such as Mika Hakkinen, David Coulthard, Lewis Hamilton and Jenson Button and still frequents the F1 paddock.