Drivers have always been alone in the cockpit, focused on the road ahead. That was especially true in the pre-communication era. They ignored what was happening up ahead or behind. They didn’t know if they were at the right pace or too slow. Or even too fast to keep the car on the track. After going round a few times, especially when incidents and events on the track occurred, they had no idea of the number of laps completed or how many were left. It soon became clear that a method of communicating with the driver had to be devised.

Firstly, a simple slate with rudimentary information scrawled on it was brandished by a member of the pit crew. As there was no “pit wall” at the time, it was a rather perilous exercise! It was therefore decided to transfer these signage operations to Mulsanne, with a telephone liaison to the pits. This was quite a practical system as all the decisions could be taken as the car passed the pits, telephoned to Mulsanne and signalled to the driver some two to three minutes later. The driver could then stop at the end of the lap to receive instructions. Mulsanne signage operations were used for several decades and feature in Steve McQueen’s movie Le Mans. Briggs Cunningham experimented with a radio link between the pits and the driver as early as 1951, but it failed to make an impact.

The 24 Hours “on the radio”

The advent of CB and FM radio in the mid-1970s saw the demise of these established procedures. By 1977, Alpine and Porsche equipped their machines with radio sets for the pit crew to transfer information to the driver. Small aerials sprouted on race cars while very tall antennas were erected on trucks in the paddocks. The signal had to reach the furthest point of the circuit, Mulsanne, through a forest of lofty pine trees that was hardly beneficial to effective radio transmission! For years, therefore, many of the leading outfits doubled up on their communication system, using both a radio link and signage at Mulsanne.

Two-way communication soon became the norm to allow the driver to inform the pits if something didn’t feel right. They could then warn the driver preparing to take the wheel for the following stint and the engineers who could determine whether the car needed to be repaired at the next pit stop. The driver could also report any hindrance on the circuit so that the information could be relayed to the sister cars.

Radio transmission has always been a challenge at Le Mans due to the length of the circuit. Not until digital radio, and more especially 4G, were recently introduced did the intercommunication between the cars and the pits become more reliable. The improvement has been such that the engineer in charge of a car and the driver at the wheel are now in almost permanent discussion, with comments pinging back and forth turn after turn. When the driver climbs into the cockpit, their first reflex is to connect their helmet to a jack plug on the dash or the rollbar and begin a radio check to be sure that dialogue can ensue.

With the arrival of onboard computers in the 1980s, in-depth analysis of the data recorded by the engine (such as speed, temperatures, pressure and fuel consumption) and the chassis (suspension movements, action of the shock absorbers, tyre temperatures, vibrations, etc.) became part of knowing the car inside out. Engineers and drivers can now literally “read” how the car is behaving lap after lap. Driver settings are also saved and synchronised turn by turn via GPS. The drivers can then see precisely, to within a metre, where they begin to accelerate, brake and turn the wheel one way and then the other, at what engine speed they change gear and what pressure they apply to the brake pedal. Their driving technique is dissected and compared to their teammates’ to help each of them to progress.

Data and discussions in real time

Data recorded in the car’s computers was downloaded at each pit stop. But like voice communication, the benefit of retrieving this data during each driver’s stint soon became apparent. Through progress in electronics (4G, then 5G, WiFi), engineers could collect technical information relating to car and driver in real time. Chassis and engine engineers can monitor the status of their own parts at all times and anticipate eventual problems. Track engineers can tell their drivers after each turn whether they have been consistent with the previous lap or slower, and whether they need to step up or maintain their pace. They also keep the driver informed of their position in the race and on the track, and indicate the cars up ahead they will have to overtake and those that are coming up fast behind.

Although settings are communicated from the car to the pits, the driver remains solely in control of the car. The engineer cannot under any circumstances alter any engine settings remotely by means of telemetry. The request can only be relayed via the track engineer or lead mechanic who asks the driver to change some setting or other using the array of knobs and switches on the steering wheel and dashboard.

With the split-second transmission of electronic data between the car and the pits, driver/engineer communications have certainly come a long way from the chalk and slate of yesteryear!

PHOTOS: LE MANS (SARTHE, FRANCE), CIRCUIT DES 24 HEURES, 24 HOURS OF LE MANS – FROM TOP TO BOTTOM (© ACO ARCHIVES): The Porsche (#3) and Renault-Alpine (#9) sported radio antennas on their left wing near the rear-view mirror; two snapshots of modern-day radio communications at Toyota, with the jack plug taped to the helmet of three-time winner Brendon Hartley, and an attentive Pascal Vasselon, Technical Director, at the Toyota Gazoo Racing control desk.