Fear not – the turbocharged Porsche 911 Carrera S can still do thisPorsche's landmark 911 Carrera S has got a turbocharged flat six engine for the first time. We ride in the revised car with a Porsche test driver
Well, that’s a relief. This new turbocharged Porsche 911 Carrera S doesn’t sound so underwhelming after all.
Perhaps the tone is a touch flatter than that produced by its predecessor at pootling-about and cruising speeds and altogether lacks the more incisive yelp of the naturally aspirated engine, but it’s still raucous enough to turn heads when the car approaches at pace.
Since Porsche confirmed that its most-loved sports car would finally be joining the engine downsizing revolution, using turbocharging to compensate for the new 3.0-litre engine's power deficit over its 3.8-litre naturally aspirated predecessor, many marque enthusiasts have worn deeply furrowed brows.
It seemed almost beyond comprehension that Porsche would risk emasculating the 911 by retiring one of its most distinctive features, one that provided its soundtrack, heartbeat and magnificently deep well of propulsion.
Turbocharging definitely hasn’t resulted in the loss of the latter. As you can read here, the 991 Gen-2 is a car that accelerates faster and hits a higher top speed yet manages to return better fuel economy than its predecessor.
About four years ago, when Porsche concluded that turbocharging was going to be the only way it could meet future emissions targets with its mainstream sports car range, it also resolved to preserve the 911’s identity as best it could.
Porsche doesn’t like calling it ‘downsizing’, accurately arguing that the new 2981cc twin-turbo flat six is still a fairly sizeable motor by anyone’s standards. The manufacturer prefers ‘rightsizing’.
In any case, the future is here, and on its website Porsche UK has already replaced the specs for the 911 (991) Gen-1 Carrera variants with those of the new turbocharged Gen-2. So if you wanted to order a naturally aspirated car through official channels, you’re too late.
The new 911 Carrera is almost ready for public viewing, with its unveiling scheduled for next week’s Frankfurt motor show. Ahead of that, we joined Porsche at Hockenheim race circuit, where the manufacturer laid on a fleet of left-hand-drive pre-production 911s wearing light disguises.
Although the cars were sitting in the German circuit’s pitlane with their drivers’ doors invitingly open and keys in ignitions, driving one was strictly verboten on this occasion. Instead, we were confined to the passenger seat alongside Porsche’s test and development drivers around the track.We’ve already done this once, with our contributor Yoshihiro Kimura enjoying a road ride in an early prototype back in February. Development has progressed since then, and the cars in front of us are just about the real deal in most mechanical aspects.
Cosmetically, they’re clearly test cars; nearly all of the important bits underneath are new, though. The optional sports exhaust is fitted to this car, which means it has two round tailpipes located in the centre, in place of the 911 Carrera S’s standard exhaust pipes exiting on either side of the car’s rear.
The rear end features other changes. The move to forced induction has brought with it some additional cooling challenges and the revised 911 has an entirely new airflow system at the rear that channels air into a vent in front of the rear spoiler. It inhales air for both combustion and intercooling, and ducts at the bottom of the bumper section allow hot air to escape.
After playing spot the difference on the 911’s exterior, I drop into the passenger seat alongside Michael Schöllhorn, one of Porsche’s durability test engineers, who gives me a tour of the new interior features.
It doesn't take long; they’re quite subtle. Most notable is probably the new 7.0in touchscreen on the multimedia set-up. There’s also a new ‘GT sport’ steering wheel that measures 360mm in diameter. This is an option, with the standard wheel measuring 375mm.
“The wheel is a bit smaller, but not too small," says Schöllhorn. "I don’t like a steering wheel that is too small because it detracts from the feeling from the car.”
Our car is equipped with the seven-speed PDK dual-clutch automatic transmission, a development of the system found in the Gen-1 991 and one that’s said to offer faster shifts.
All 911 Carreras now get Porsche Active Suspension Management (PASM) as standard. Four-wheel steering, as found on the GT3, is now optional on the 911 Carrera S but wasn’t fitted to our test car.
In standard fettle, the revised chassis is 10mm lower than its predecessor, and keen drivers can opt to go an additional 10mm south again by specifying a Sport chassis.
Another option is the Sport Chrono Package, which was on our test car. The steering wheel now features a new rotary switch to toggle between the driving modes – Normal, Sport, Sport Plus and Individual – rather than having to use the buttons near the gearlever. It’s Porsche’s answer to Ferrari’s manettino dial.
Schöllhorn gives me a running commentary as he heads onto the track and demonstrates the driver modes.
“It was absolutely necessary that this engine should feel like a naturally aspirated engine,” he says as he switches from docile Normal mode up to Sport and quickens the pace.
“The more revs you get, the more power you get. In terms of throttle response, you can’t feel a difference,” he assures me, although we’ll have to wait for a definitive verdict on that when Autocar’s own testers get behind the wheel.
From the passenger seat, though, it does seems that the further you advance through the sporty drive settings, the more the engine acts and sounds like its naturally aspirated forebear. It’s certainly not lacking for power, delivering maximum torque from low 1700rpm and serving it consistently until 5000rpm.
“In Sport mode, the turbocharger wastegates will open if I lift off the throttle, but in Sport Plus the wastegates do not open. So in that mode, we have instant torque if we go back onto the throttle again; it’s impossible to feel that it is a turbo engine,” says Schöllhorn.
Porsche hasn’t gone down the road of using digital trickery to make the blown 911 Carrera S sound like something it is not. It has an analogue sound duct that transmits the engine sound to the cabin. Each variant will have specific sound duct tuning.
What’s clear is that with the optional sports exhaust fitted and the driving mode switched to one of the more aggressive settings, the Carrera S can invoke a fairly meaty noise.
Weissach’s engineers have overhauled the Porsche Stability Management (PSM). With the Sport Chrono Package, there’s a new PSM Sport mode that is activated by pushing the PSM button on the centre console.
PSM Sport relaxes the stability control systems without turning them off completely, permitting large yaw movements and more slip at the rear wheels. Porsche reckons it should bring enough engagement to satisfy most keen track day aficionados.
“PSM Sport is designed so that you can get some drifting angles but not too much. It’s nearly impossible to spin the car in this mode,” Schöllhorn says, although from my seat he seems to be trying quite hard to disprove his own theory, pitching the 911 into a glorious power slide over the kerbs at the exit of the Sudkurve right-hander.
If you really want to, it’s still possible to completely switch off the PSM with a long prod of the button, although even that doesn’t prevent the systems from providing a safety net under heavy braking.
“Now we’ll go for one fast lap,” promises Schöllhorn, and it’s abundantly clear that turbocharging hasn’t dulled the exquisite balance and measured, obedient responsiveness of the 911 Carrera S’s chassis.
“The balance is perfect,” he grins at me as the speedo’s needle reaches 200kph (124mph). “You still feel like a big child when you drive this car.”
On Hockenheim’s start-finish straight, Schöllhorn revs the car out to its maximum 7500rpm limit, just to prove that the new flat six can achieve what its spec sheet claims. Both Carrera and Carrera S have the same maximum engine speed; the 50bhp difference in power between the two cars is the result of different turbo compressors and tweaks to both the exhaust and engine management.
“With this car, it is possible to use it for all-day use, or you can go to a race track and have a lot of fun. It’s a typical 911,” he says.
Turbocharging the 911 Carrera hasn’t exactly turned it into a shrinking violet. Schöllhorn makes a valid point about how each subsequent generation of Porsche’s sports car has moved the game on. “You have to remember that the 959, which is 30 years old now, had the same power and speed as this car," he says. "The next car which reached that level was the 996-generation 911 Turbo. And now this 911 Carrera S has the same performance.”
It’s not all about performance. The switch to turbocharged engines, allied with some pretty nifty powertrain innovations and increased efficiency of auxiliary components, make the new engines up to 12 per cent more frugal than their forebears. Although such figures are unlikely to be foremost in a prospective 911 Carrera owner’s mind, it’s a useful increase nonetheless.
This is just the start of Porsche’s grand plans to roll out turbocharged derivatives, but on this evidence it’s not necessarily the end of the world. After all, there’s potential for extracting more power from the turbocharged engine than the naturally aspirated forebears, so it’s safe to say Porsche’s future could include some suitably unhinged machinery.
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