With every major rule change in Formula 1, designers are frantically looking for loopholes in the rulebook that will give them a competitive edge. With this year’s rule changes, no major loopholes appear to have been found. But in 1997 it was McLaren with an F1 car with two brake pedals that was half a second per lap faster than the rest.
Three pedals in the car did the usual things, namely accelerating, braking and clutching. But the fourth pedal did have a special effect. By pressing it, one rear wheel could be braked independently of the others. Think of it like driving a tank. When a tank wants to steer, it does so by stopping one track and turning the other. With this extra pedal, Mika Hakkinen and David Coulthard were therefore able to turn-in much better and faster than the other drivers and they were able to counteract understeer.
Not only was the McLaren half a second faster per lap, it was also very cheap to implement. All parts for this addition were already present at McLaren. Chief designer and creator of the idea Steve Nichols thus found free speed for his cars. Still, the entire party lasted only half a season.
The end of the F1 car with two brake pedals came when an observant journalist took a picture of the inside of the cockpit. This is where McLaren’s secret came to light. Ferrari was quick to have the design made illegal by the FIA and finally succeeded in the second race of 1998. Despite the ban, Mika Hakkinen still managed to become champion that year.
— McLaren (@McLarenF1) September 2, 2015