Why F1 ‘can never get rid’ of porpoising and could become even ‘more severe’

Michelle Foster
Ferrari following Alfa Romeo. Bahrain, February 2023.

A Ferrari follows an Alfa Romeo in pre-season testing. Bahrain, February 2023.

Although it’s notable there is a lot less porpoising on this year’s Formula 1 grid, Jan Monchaux says don’t be fooled, it’s still there and “you can never get rid of” it.

Introducing new technical regulations last season, many of the Formula 1 teams suffered with porpoising, which is a known consequence of using ground effect aerodynamics to create downforce.

While some teams had hardly any bouncing, others, such as Mercedes, really struggled with it with rivals saying they should raise the ride height of their cars to minimise it.

That, of course, robs the car of downforce and, ultimately, pace.

After much lobbying, and it must be noted Mercedes weren’t the only team concerned about the long-term effect porpoising could have on their drivers, the FIA raised the floor edges of this year’s cars by 15mm.

That has effectively reduced the downforce of the cars, which has helped to minimise porpoising.

But Alfa Romeo technical director Monchaux says don’t be fooled, it’s still there.

“In our opinion, you can never get rid of porpoising,” he told Auto Motor und Sport. “It will always be there because it is a physical phenomenon.

“You can only push the moment from when it starts, either in one direction or the other. That depends on the height.

“The rule change has, in our understanding, shifted the speed at which porpoising actually begins. And in the direction of higher speeds. So now, compared to last year, the whole issue is much less visible.

“But it’s still there. It lurks. When the wind shifts a bit we see some oscillations depending on the setup. But the amplitude is significantly less than last year.”

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Explaining why the 15mm makes such a big difference

Asked to explain how the FIA’s ruling to raise the floor edges, as well as the diffuser throat height, played such a significant role in reducing porpoising, Monchaux explained: “In order to generate downforce, you want the car to be close to the road.

“Think of it this way. You have a record. Below is the street. There is a negative pressure. There is a bit of overpressure. Vortices are automatically created because the air flows from high to low pressure. This means that rather complicated vortex structures develop at the edge.

“The closer you are to the ground, the greater the pressure difference. These vortices then become all the stronger. They then either penetrate the diffuser or not. All vertebrae interact with each other.

“If I raise the edge, the vortex structures become weaker. They are less likely to eventually spiral out of control and trigger instability. Going a little higher weakens the structures. In this respect, you can push the porpoising a bit.”

But those weren’t the only changes as the FIA also introduced more stringent tests for flexi-floors with the Frenchman saying if they hadn’t done that, the “teams would probably have tried to regain those 15 millimeters in high-speed passages. Then there would again be cases where the car jumps heavily.”

Stable rules could see porpoising ‘come back more severely’

With the Formula 1 teams always striving to find more downforce, the Alfa Romeo tech boss says porpoising could become even worse in the years to come.

This year the FIA intervened to negate the downforce the teams found and they may have to do something similar down the line.

“If the regulations were stable for years, which is wishful thinking, and we add downforce every year, the problem would relatively certainly come back more severely,” Monchaux said.

“The porpoising would start earlier again because then we just create so much downforce that all these vortex structures are relatively strong.

“15 millimetres wouldn’t be enough. That’s too small a step. You would have to be 50 millimetres high for that. Then we would have time.”

In the meantime it’s up to the teams to make life a little more comfortable for their drivers, even when they themselves aren’t always in favour of it.

“You would be surprised how tough it is for the drivers,” he added. “We always try a softer setting. That also helps if the car jumps a bit again.

“But we’re talking about pro racers. They know that when they have it a little harder, they are faster. They’re not sitting in a Mercedes S-Class driving around for a bit on a Sunday afternoon. It’s a tough sport.

“So we’re not getting out of there. But it is also not necessarily desired. The balance between stiffness and aero performance on the one hand versus more ground clearance clearly goes in the first direction.”