McLaren technical boss explains rule change that ruined team in Bahrain

Oscar Piastri’s start to Formula One hasn’t gone to plan at all - and now the tiny detail that screwed him has been revealed.

BAHRAIN, BAHRAIN - MARCH 02: Oscar Piastri of Australia and McLaren looks on in the Paddock during previews ahead of the F1 Grand Prix of Bahrain at Bahrain International Circuit on March 02, 2023 in Bahrain, Bahrain. (Photo by Clive Mason/Getty Images)

The eyes of the Formula One world were on Oscar Piastri in Bahrain, as were a nation of Australian motorsport fans looking for a new hero after the departure of Daniel Ricciardo.

Unfortunately, the hottest young property in motorsport flopped on Grand Prix debut, starting 18th and not getting to complete a pit stop in anger as he told his engineer he “lost the gearbox.”

His teammate Lando Norris is himself extremely highly rated, and is considered unlucky to not have a Grand Prix victory to his name already, but finished two laps down on the lead lap after having to pit six times.

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McLaren admitted they were “not entirely happy” with the state of the car that was revealed at launch, and are hoping for improvements through upgrades over the course of the season.

Now, the specific regulation change that has ruined Piastri’s season can be revealed, and it’s likely to be the fault of their engine supplier, Mercedes.

“Where this (the major issue) happened actually is when we took the 15mm floor step,” said McLaren’s technical director, James Key.

Oscar Piastri’s race was cut short owing to mechanical issues, with the Australian having to retire early. (Photo by Mark Thompson/Getty Images)

In an attempt to definitively cancel out the porpoising that plagued the 2022 cars, particularly Mercedes, the FIA imposed a change in the height of the floor, which raises the cars by 15mm, and prevents floor stalling, but at the expense of a reduction in total downforce, making the cars slower overall around the track.

Porpoising occurs when the active aerodynamics that are designed to suck the cars to the road, which rely on a negative difference in air pressure between the underside of the car and the top of the car, stall as a result of the car being pushed too close to the road surface.

This results in the car violently bouncing up away from the road before being pressed back down again, affecting grip, acceleration and stability.

With Mercedes the most affected by the phenomenon, the Mercedes-powered teams were at the forefront of the push for a 25mm increase in floor height over the summer break, but the FIA settled on a compromise figure of 15mm given that most teams besides Mercedes had solved their porpoising woes.

Piastri was at the centre of an incredibly high profile and heated race for his signature before joining McLaren from rival team Alpine. (Photo by Peter Fox/Getty Images)

“This sounds very small, but these floors are huge and incredibly sensitive,” said Key.

“Look at how much downforce it generates, massive.

“So when we did it on our car, it actually gave us a much bigger loss than anticipated.

“It seems to have affected different teams in different ways.

“And to a certain extent, it seems to be related to the floor edge geometry that you’re running at the time.

“Last year, there were two camps beginning to develop, one which we were in, and one which probably the majority of teams were in.

“And when we took that [15mm] step, it was a really big knock for us.”

Key explained that the commitment to McLaren’s existing floor architecture when the changes to regulations were put to teams stalled the Woking team’s development progress on the floor itself, putting it significantly behind the 8-ball by the time 2023 rolled around.

“The trying to recover with what we knew at the time, and this was probably September time, we were thinking, this is not working, we’ve actually got to change direction entirely with these geometries,” he said.

“Which is a big change, because they’re very big projects, and very complex projects.

“So I think the timing of the (regulation), and the fact that we took a particularly large hit, and then that it clearly wasn’t going to come back easily, meant that we had to change direction quite late.”

Tensions were running high between the Team Principals at this group meeting 😅

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The changes in regulation were hotly contested, with Toto Wolff shown in season five of the Netflix documentary series Drive to Survive arguing with Red Bull Racing team boss Christian Horner about increasing the ride height, citing safety concerns as well as driver welfare concerns.

Lewis Hamilton, George Russell, Carlos Sainz and Daniel Ricciardo were all vocal about the impact it had on their bodies, with Ricciardo describing it as a “shaking of the brain and the spine.”

Norris said the McLaren’s direction had to be clearer in order to be able to compete.

“I think it’s a mixture of two things,” he said.

“One is the general balance, and two is overall downforce.

“What we’re having in Baku (the fourth round of the championship) should be what we’re starting the season with.

“If you want to be a top team, it’s where we should’ve started the season with those kinds of parts which are coming.”