34 FORMULA E BRAKES
ABOVE: The E-prix travelled
to New York in July 2019.
Photo: Formula E
BELOW: Brembo developed an
aluminium housing with linear
bushings and a single-stage
tandem master cylinder. The
master cylinder feeds both
the front and rear systems,
imposing a fixed braking
force distribution
systems that are more evolved. Other teams have the
money but prefer to take a more conservative approach
and use the simplest logic – having the re-gen system on,
or the friction braking system on, without any mixing or
fading between the two. Then there are those who would
like to do some development work, but unfortunately
don’t have enough budget to test the options.”
Drivers typically run the same control logic, but
can tweak the brake balance to their preferences – for
example, for the braking system or the re-gen system to
be more or less aggressive – and the parameters that drive
the controls can be adjusted to better match the driver’s
feel and style. A driver can also switch between predefi ned
setups multiple times during a lap to provide different
behaviour from one braking manoeuvre to the next.
Brembo has developed a conventional hydraulic setup,
but under the Gen2 regulations, brake-by-wire (BBW)
systems are developed by the teams and manufacturers
as part of their remit to develop individual powertrains,
providing an additional avenue for performance gains.
On a Formula E car, BBW modulates the pressure that is
generated on the pedal through Brembo’s single-stage
master cylinder, a tandem affair that actuates both
VehicleDynamicsInternational.com • November/December 2019
front and rear axles, based on input values from the
vehicle electronics.
Brake-by-wire provides additional development
opportunities for the teams. Brembo, while not acting
as a BBW supplier, is able to tap into its experience of
BBW in Formula 1 – in which Clemente also works as a
race engineer – to support the teams with its integration
into the overall braking system to get the most from the
friction materials.
Clemente expects the SRT05Es to work the brakes harder
in Season 6, which kicked off in Diriyah, Saudi Arabia,
on 22 November. Porsche and Mercedes-Benz swell the
ranks of the offi cial factory teams, increasing the grid
size from 22 to 24 cars and, it is expected, raising the
level of competition in an already competitive fi eld.
“The teams have also had the summer to work with
the car, to test it, to develop their own strategies and
know-how,” he says. “The teams know the car better
than a year ago and the strategies around it, so will
be able to push it harder. The cars will have evolved and
for sure there will be an increase in performance, which
will increase the requirements on the brake side for
the next season.”
/VehicleDynamicsInternational.com