Peugeot Sport’s technical director Olivier Jansonnie told media at Imola that the addition of a rear wing to the new 2024 9X8 was driven by the change in tyre size dimensions.
The new version of the 9X8 Le Mans Hypercar runs 29-inch tyres at the front and 34-inch tyres at the rear, rather than 31-inch tyres all round.
Speaking to media at Imola, ahead of this weekend’s six-hour race, he said: “Since we did that [change the tyres] we had to rebalance the car.
“The weight distribution of the car is also changed to try to make sure we work at the optimum weight distribution for those tyres.
“So it’s all driven by the tyre.
Peugeot had initially believed that the 31-inch tyre choice would be compensated by Balance of Performance, despite Peugeot’s simulation models showing the 29/34 route was a better option. However, this did not end up being the case, at least not entirely.
“It was completely clear for us from that [introduction of 29/34 rules], we said that the BoP could compensate for that,” said the Frenchman.
“At the time, it was already quite clear for us, from simulation, that the 29/34 tyres were actually more performant, but at that time, it was not allowed. So we went for the other dimensions.
“When the regulations were opened to 29/34 tyres for the LMH cars, we just raised our hands saying, ‘Okay, look, there’s going to be something wrong there, because we know that’s going to be more performant.’
“With that option in our pocket, we have taken it and couldn’t do it. Having said that? We, and I think everybody actually, not only us, probably underestimated the difference between two the dimensions.”
Jansonnie also described how significant the changes were between the old and new 9X8 from the new aerodynamic concept, notably introducing a rear wing and a new floor.
“Changing the tyre dimensions is driving the aero and it’s driving the rear wing… that is why the car is completely different,” he said. The new 9X8 only carries over the same cooling ducts and monocoque chassis, with almost all the aerodynamic surfaces being brand new.
Meanwhile Nico Muller, one of the drivers in the #93 Peugeot 9X8, believes the car feels more ‘connected’.
“I think the car just generally, it feels a bit more connected. It does respond to setup changes a bit more logically, it’s slightly easier to get it into the working window,” said the Swiss driver.
Besides a podium finish from last year’s 6 Hours of Monza, and their more recent contention at the 2024 Qatar 1812 km season-opener – before they ran out of fuel – the initially homologated version of the 9X8 struggled to match the pace of their rivals.
The Stellantis manufacturer will continue to adhere to the rule allowing deployment of their KERS hybrid system above 150 kph, as these new tyre dimensions should enable better traction at the rear at the low speed corners.
