The mid-season rule clarification or update issued in August 2024 by the Fédération Internationale de l’Automobile (FIA), motorsport’s governing body, targeted Formula One cars’ braking systems.
Graham Duxbury
By Graham Duxbury
The long-standing rule states: “The brake system must be designed so that within each circuit, the forces applied to the brake pads are the same magnitude and act as opposing pairs on a given brake disc.”
However, new wording was added: “Any system or mechanism which can produce systematically or intentionally, asymmetric braking torques for a given axle is forbidden.”
Does this suggest that a team has been found to have revisited the enigmatic “brake-steer” concept that was invented back in 1997? Has the FIA moved to close a loophole in the current regulations to prevent teams from adopting similar solutions en masse?
According to respected journalist Peter Windsor, “word on the street” is that more than one team has been using such a system. Red Bull seems the obvious culprit due to the team’s fall-off in performance, he says.
However, he notes that Ferrari’s unusual 100-degree front brake temperature imbalance reported on Charles Leclerc’s car during the Bahrain Grand Prix might have revealed a failure of an asymmetric braking system.
Back in ‘97, eagle-eyed F1 photographer Darren Heath spotted Mika Hakkinen’s McLaren with a single rear brake disc uncharacteristically glowing orange in the middle of a corner.
Something about it wasn’t right; he thought. F1 drivers don’t brake mid-corner – at least, not if they want to go faster. He set out to unravel the mystery and was able to get photographic proof of an ingenious – and perfectly legal at the time – extra brake pedal hidden in the footwell of the McLaren’s cockpit.
What was its function?
Simply, the extra pedal allowed the rear brakes to operate on one side only. When applied mid-corner, it would brake one of the rear wheels and in order not to slow the car down the driver would accelerate at the same time.
It was the combination of pressing two pedals together that was the key, This put more torque through the outside rear wheel and less through the inside, applying a yaw moment to the car which helped to turn or rotate the car.
This solution was worth at least half a second per lap, according to McLaren insiders.
The idea originally came from Steve Nichols, McLaren’s chief engineer at the time, who claims he literally had a “Eureka!” moment in the winter of 1996.
“It was Christmas time and I was lying in the bath,” he recalls in a much later interview reported in Motor Sport Magazine. “We typically set the cars up with quite a lot of understeer – at the time we had fairly skinny rear tyres and fairly meaty front tyres – and I had this idea to put a rear brake on in the corners, to sort of dial out the understeer.
“Paddy Lowe was head of R&D at the time, and this would be considered an R&D project. I told him I wanted to try this thing where we have an extra pedal in the car, and we put the right-rear or left-rear brake on to balance the car.”
Nichols claims the technology was quite basic and inexpensive. “It was just a simple piece of kit comprising fifty quid’s worth of parts scavenged from the back of the transporter,” he says. “All we had to do was put an extra master cylinder on the car, and run a length of brake hose.”
Initially, only the left or right rear brake was selected to operate, depending on the layout of the corners. Later both brakes were addressed and a switch was added enabling the driver to decide on the appropriate corners for the system’s use.
Having re-read the rulebook and studied the regulations, Nichols was confident that his braking system was legal. However, rival teams attempted to have McLaren’s secret advantage banned, claiming it would cost vast amounts of money to devise their own unique solutions.
McLaren’s system – later dubbed the “fiddle brake” by Ferrari technical chief Ross Brawn – was eventually banned but not before the team had won several grands prix with it installed. The sanction was imposed.on the basis that it constituted four-wheel steering although it was obviously not realigning the wheels.
Today’s fiddle brake ban is imposed only on the basis that it contravenes the spirit of the regulations.