They need to clip the apexes, hit their braking marks and maximise cornering speeds, but that’s only part of their job, especially in the modern era. Endurance racing in the IMSA WeatherTech SportsCar Championship is a multi-class discipline: dealing with slower or faster cars — or both — is an important part of the game. Then there’s the task of optimising the electronic systems, increasingly part of modern motorsport, in the name of performance.

IMSA has four classes. The high-tech GTP hybrid prototypes at the front of the field are joined by their slightly slower siblings in LMP2, a much more controlled category using a spec normally-aspirated V8 engine, and then there’s the GT3 machinery in the twin GT Daytona divisions. These cars are split in two according to the make-up of the driver line-up: GTD Pro allows, as the name implies, all-professional crews, while GTD is a pro-am category in which the place of the amateur, so important in endurance racing, is enshrined in the rules.

“What makes IMSA so special as a series is that you have multiple categories,” says Jenson Button, who finished third in the Rolex 24 at Daytona in January driving for the Wayne Taylor Racing with Andretti Acura GTP team. “There are such different speeds around the track that you are never out of traffic whether you are in an GTP, an LMP2 or a GTD car.

“You never have a clear lap. For the drivers, that’s 24 hours of mayhem, but also for the fans, the spectators, because there is always something happening. If a GTP car doesn’t overtake another GTP for an hour, it is still making 100 overtakes in that hour.”

The drivers also have to keep focus on what’s going on inside the cockpit, too. Nowhere more so than in a GTP car built to the LMDh ruleset, which also allows entry into the FIA World Endurance Championship’s Hypercar class. It is a high-technology category utilising a common hybrid system that has been developed with Bosch Motorsport as one of the key partners.

The driver’s role in getting the most out of the electronic systems is complex. Button may be a Formula 1 world champion and a veteran of 306 grands prix, but his job in the cockpit of an LMDh is much more involved than anything he experienced in single-seaters.

Button explains there are far more controls for the driver in sportscar machinery than in F1

“In F1, we were very limited in what we could do,” says the Briton, who is contesting the WEC in 2024 at the wheel of a Porsche 963. “We didn’t have traction control and many other controls weren’t left to us. Whereas here there are hundreds of switches!”

Bosch has had a long involvement in motorsport across a multitude of disciplines. It is an involvement that has grown and continues to grow, nowhere more so than in IMSA with LMDh machinery.

“In terms of racing electronics, the things that Bosch has been heavily involved in from day one are some of the most fundamental parts of the internal combustion unit, the spark plugs and the fuel injection system,” says Jacob Bergenske, director of Bosch Motorsport North America. But in today’s world of high-tech motorsport, what he calls the “computerised era”, the scope of Bosch’s involvement has dramatically increased.

“It starts with really small things, like pressure and temperature sensors, the vehicle motion position sensors, which is really cool technology,” explains Bergenske. “Then we go on to the hybrid side and the spec components, the motor, the motor controller and the hybrid control unit and the electronic braking system.”

The list of Bosch components on the car doesn’t stop there. There’s also the low-voltage wiring harness, the loom enables all the electronic systems to talk to each other. There’s also a high-voltage harness between the battery and the motor generator unit.

“We have dash displays that give the drivers information,” continues Bergenske. “We have the scrutineering data logger and the telematic systems based on our LTE technology that gets information up from the race car into the Cloud in real time, and then we can disperse the data from there.”

Bosch’s products can be found across IMSA’s various classes

GT3 cars aren’t hybrids, but Bosch’s products are still to be found on the machinery competing in the GTD ranks.

“Peek inside some of these GT3 cars, and it is literally our catalogue in there,” says Bergenske. “There’s our driver display, our world renowned collision avoidance system with radar technology, our ABS systems, our engine control units, our fuel systems. I’m sure there are a few things I’m missing!”

The integrated approach offered by Bosch is crucial, says Bergenske.

“Having that all under one roof is important because the technology is changing so rapidly,” he explains. “For someone to go out and say, ‘OK I need to find this gadget, I need to find that gadget, and then I need to figure out how to get them all to talk together is very time consuming.”

Getting on top of all the electronic controls and systems isn’t the work of a moment for the drivers, either. During his initial laps aboard his WTR Andretti Acura, Button says, “there wasn’t enough time around the lap for everything to go through your head”. He reveals that, while he was getting up to speed, he was asking himself, “which way is that switch — it takes some time to get into it.”