How Porsche Gave the World More Turbos, Faster
Buried deep within the 2017 Porsche 911 Turbo is an engineering “no-duh.”
Talk to anyone with a cursory knowledge of the widowmaker from Stuttgart and they’ll say the old Turbo 911s required three feet in any given corner: one for the brake, one for the clutch, another to feed the throttle so you’re not kicked in the lumbars when they come on strong.
Last generation’s 997 added variable turbine geometry, which smoothed the edges somewhat—but the knife was just as razor sharp.
For this year, engineers overhauled the fuel system in the 991 Turbo to highly pressurize the system to give more finite control and quicker response. The byproduct? A system that can keep open the throttle valve during overrun, when fuel isn’t needed for acceleration and when turbos typically slow down, to use air to keep the boost primed. Only about 1 to 2 psi is loaded into the system using air fed into the engine, but it keeps the turbos at a steady gallop—ready to sprint.
Engineers stop short of calling it “anti-lag” for good reason; the system developed in rally cars and for Formula 1 racers is fundamentally different. Rather than delay timing and burning unspent fuel in the exhaust to spin up the turbo, Porsche keeps the party up front.
The effects are immediate and alarming. In our drive of the 911 Turbo S, all 540 horsepower (580 hp in the Turbo S) are ready to pounce. Not as violent as earlier 911 Turbos, but every bit as disarming—and this time, even in mid corner—and never boring.
The system is already in use in turbocharged 3.0-liter Carrera models to assuage buyers that the cars are every bit as ready as the naturally aspirated flat-6 models. In 911 Turbo models, it’s more about predictability.
In either application, it’s a system that we expect to see more of in the future.