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| © Porsche Porsche's electric sedan has regenerative braking, but the car still has huge 16.5-inch rotors and ten-piston calipers up front. It all has to do with Porsche's braking torture test. |
By Chris Perkins, Road & Track
One of the most unique things about driving an electric vehicle is
regenerative braking, where the electric motors that power the car help
to slow it down, charging the car's battery in the process. Porsche
engineers assume that drivers of the new Taycan electric sedan will
accomplish around 90 percent of their braking via regen.
So why does the Taycan have some of the largest friction brakes ever fitted to a road car?
The Taycan Turbo gets conventional steel brake rotors measuring 16.4
inches up front and 14.4 inches at the rear. Standard on the Turbo S,
and optional on the Turbo, are carbon ceramic brakes, 16.5 inches up
front, 16.1 inches in back. Both brake setups utilize giant 10-piston
front and four-piston rear calipers. (The largest factory brakes in the
world are the 17.7-inch front rotors available on the Bentley Bentayga.)
Big
brakes are common on Porsche's high-performance models, and with up to
750 horsepower and a 2.6-second 0-60 sprint in Turbo S trim, the Taycan
is certainly a performer. But there's a particularly interesting reason
why Porsche fit the Taycan with especially gigantic brakes.
A
spokesperson told me that every Porsche is required to pass a braking
torture test: 25 stops in a row, from 80 percent of a car's top speed
down to 90 km/h (56 mph), with every fifth stop involving full ABS. For a
car to pass, it has to generate between 0.8 and 0.9 g of deceleration
every time.
The Taycan presents a unique challenge. Its 161-mph
top speed is relatively low compared to other Porsche products. And the
EV boasts ultra-quick acceleration, so it doesn't take long at all to
reach 80 percent of top speed, around 129 mph. This meant that, during
Porsche's braking test, the Taycan didn't have much time at all for the
brakes to cool between stops.
Rather than change its braking
performance standards for the Taycan, Porsche solved the problem by
fitting those enormous brake rotors and ten-piston calipers. It seems a
little funny given that, in normal daily driving, those giant brakes
might almost never be activated, thanks to the car's regen capabilities.
But the Taycan's brakes are critical to offering the performance
Porsche demands—including the car's 7:42 Nürburgring lap time.
