Euroformula ended a long association with Michelin to adopt Hankook tyres for 2023, but a supply chain dilemma meant Euroformula then changed to Pirellis after one weekend of racing.
The tyres introduced for round two of the Formula 3-level series at Spa-Francorchamps posed an even greater challenge than adapting to Hankooks, and a representative of Motopark – Euroformula’s dominant team – told Formula Scout “in the high-speed corners it’s not to easy” as “the problem is they’re not designed for F3, it’s designed for Formula 4″.
BVM Racing had experience of the tyre from F4, but team manager Giuseppe Mazzotti treated the Spa round as testing, particularly with understanding the “big difference” from how the tyre behaved in qualifying compared to races.
The team’s race engineer Matteo Tirinnanzi explained the significance of the Pirelli switch in more detail.
“Dimensionally they’re not too different [from the Hankooks]. The main concern is sidewall stiffness. So for a given inflation pressure, the deflection of the tyre is much more significant. That wreaks havoc with ride-heights, aero load.
“It’s the same tyre as used in F4, but we have a lot of downforce, so that really puts the tyre under stress, and we have to somehow compensate these changes in ride-height. Because our floor is quite sensitive for the downforce. So on one side it would be nice to run very high pressures to keep them stiffer. But if you keep them high, they slide all over the place.”
That is particularly the case in high-speed corners, “especially on the rear” which can “be quite unpredictable”.
“We just need to try to adjust for it. It’s not the first time this tyre has been used on F3 cars or Dallara 320s. It’s been run in the Italian F2000 Trophy for like six years, on F3s, so it’s not really a novelty. It just requires special attention [for set-up].
“And having worked with this tyre in other championships, when you’re not using – let’s say when you have a serious driver pushing the tyre, the limit is different. It’s a good thing that it doesn’t suffer from overheating.”
Euroformula is already seeking a 2024 contract with Pirelli, but that may require aero adjustments to its Dallara 320 car. One idea is changing the front geometry and introducing larger rear tyres.
“But to be honest, once you’ve catered for these stiffness changes, it’s a quite a solid, reliable tyre,” Tirinnanzi continued.
“I’ve never really had a blistering issue, explosions, bursting, never. I didn’t mind the hard compound Hankook that we tried in Portimao. I thought that was surprisingly good. At the same time I felt their soft compound, well, supersoft compound, the C92, would overheat very easily. It’s a tyre that has blistered. So I don’t mind their C72 or the Pirellis.”
Round three takes place this weekend at the Hungaroring, which has lots of corners, then round four in July is at a hot Paul Ricard. Set-ups will have to accomodate hot temperatures, meaning dialling in instability for the start of races to avoid it at the end of them.
“Considering the length of races, you cannot expect to be fast over the entire race. You’ll have to try to find a window where you think you’re going to be faster than anybody else,” said Tirinnanzi.
“Also the aero loads I think will be slightly different from what we’ve seen with the Michelins and the Hankooks, especially because excessive aero loads at one point will saturate what the tyre can do. Because of the deflection.”
He concluded that “we’d like to test a little bit more, because we’ve realised that it’s a slightly more complex change from Hankooks to Pirellis than it was from Michelin to Hankook”.