Inside the all-new Porsche 911

We liked (so far)
?>> New engines promise improved late-life reliability
?>> Astonishing light-throttle fuel economy?
>> Now even lighter

Not so much (so far)
?>> Induction-note diaphragm a bit contrived?
>> Local pricing
>> Still looks very little different to untrained eyes

The test driver crests the brow into the downhill hairpin and neglects to brake. They do that sometimes. Just for science, they insist.

He cranks the new, electro-mechanical steering hard over to the right and the all-new 911 responds with a sustained understeer slide that doesn’t even hint at the nameplate’s traditional chatter.

He’s off the throttle, though, even if he’s not braking, and the 911’s engine responds with a heart-warming, enticing crackling, burbling overrun that seems to last forever. It’s like it’s begging you to engage yourself in the experience and never let go.

In a handful of metres, though, the nose has reorganised itself, so he stamps on the throttle in second gear. The all-new flat-six howls as sound-generating trickery combines with mechanical hard work to saturate the cabin with a noise eerily familiar to anybody who’s ever driven a 911. The wheel flicks back the other way as the freshly sculpted tail breaks free in a wild, opposite-lock slide towards the retaining wall, but my pilot never lifts from the throttle and the new, smaller engine in Porsche’s sentimental favourite cracks hard against the rev limiter and stays there.

Eventually, it all straightens up and he grabs third, and the 911 blasts forward in its traditional silken howl until it hits a wet patch under the trees as it comes on to the high-speed front straight. There, it eases its tail sideways again, drifting almost languidly towards the armco at 140km/h before a neat flick of the steering wheel brings the 911’s focus back from fun to straight-line speed…

They might have changed almost every bolt in the 911 and its body, engine, gearbox, suspension, steering, electronics and brakes may all be shiny and new, but the spirit of the 911 is never far away.

The all-new car is 100mm longer in the wheelbase, too, which is a blatant sop to ride comfort. Its engine has also shrunk, for the first time in 911 history, from 3.6 litres to 3.4 and it drives through either a seven-speed double-clutch gearbox or, for the first time in any car maker’s history, a seven-speed manual.

None of that hampers the acceleration, because the 911 now hauls to 100km/h in 4.8 seconds as a manual (4.6 with PDK) on its way to a 289km/h top speed (287 with PDK).

Step up to the harder-hitting Carrera S and the sprint takes just 4.5 seconds (4.3 with PDK) and it runs to 304km/h (302km/h with PDK). What’s more, the PDK version of the Carrera S cuts half a second from the manual’s 0-200km/h time, getting there in 13.9 seconds. There is an optional Sport Plus kit that slashes the 0-100km/h time to 4.1 seconds and cuts another 0.3 seconds from the long sprint.

Yet the real measure of a car’s speed these days isn’t straight-line sprints, but the industry’s favourite test bed, the Nurburgring. Porsche insists the Carrera S will lap the Nordschleife in 7min:40 -- a full 14 seconds faster than its predecessor.

So it’s faster.

It’s also more economical. In fact, Porsche insists it’s the most economical 911 in history, with the 911 Carrera PDK recording a combined consumption figure of just 8.2L/100km and posting sub-200 gram CO2 emissions numbers. The Carrera S is thirstier, but not by much, with the PDK version posting 8.7L/100km and 205 grams of CO2.

The new engine runs combines a 97mm bore and a 77.5mm stroke to deliver seriously oversquare performance characteristics. Porsche then fills in the low-rpm 'holes' with clever electronics, multi-hole fuel injectors and variable valve timing and lift on the inlet cams to flesh out the torque curve.

The 3436cc flat six also runs a taut 12.5:1 compression ratio that helps it to 257kW at 7400rpm and 390Nm at 5600rpm. Its rev limiter chimes in at 7800rpm -- thus it revs higher and harder than its predecessor, too.

While it runs exactly the same stroke, the Carrera S has bigger holes than the Carrera, with a 102mm bore giving it an even 3800cc of capacity. It uses that extra bang space to help itself to 294kW and 440Nm at the same revs as the 'cooking' model.

“We wanted it to be the best 911 of all time,” Porsche development boss, Wolfgang Hatz, told motoring.com.au.

“Driving a 911 is and always has been a very emotionally charged thing to do and it will always remain that way.

“We wanted more comfort in the suspension and more space and better ventilation and heating, and the key is the new platform.

“It’s 100mm longer in the wheelbase and wider in the tracks. Almost half the body-in-white is aluminium, including the doors and the roof, and it’s lighter and stiffer in the body and that’s the basis for everything.

“Then we gave it a smaller engine with higher revs and more power and less consumption and we’ve done a lot of work on the sound between the air filter and the tailpipe.”

And so it appears. But at least some of the soundtrack is artificial in that it adds noise that doesn’t actually need to be there, just to make the new 911 sound and feel more like the old 911.

“What is so typical about the 911 sound that is emotional across all generations? In the 911, all sound-generating sources are found in the rear. Mechanical components create high-frequency sound like a turbine, basically, and it gives the impression of high quality,” he insisted.

“Intake and exhaust sounds depend on low frequencies. The frequency and volume you need to give full body with intake sounds are a bit more low volume and we can only hear them inside the car, while exhaust can be heard inside and outside it.

“But for the intake air sound, this increases when you play with the throttle. At each rpm the driver wants to hear a balanced sound, so we work on that because otherwise the pure mechanical engine sound would overwhelm the intake sound," Hermann continued.

“We want to make sure that the message is about an engine condition so we designed a path in the air intake to divert air through a separate tube before the manifold and it vibrates a diaphragm to create and enhance the intake sound,” he explained.

But that’s not all. The 911‘s engine bay also has a pair of extra diaphragms in the air intake at the filter level which create noise that is passed on to the passenger compartment, depending on the rev ranges.

Hermann again: “There is a certain frequency where this system can create too much noise so we added a small extra volume area. If you reach the rpm at which the intake noise is louder than normal, we open the valve and it starts to vibrate another diaphragm, which deletes the highest sounds so it goes back to normal.

“The diaphragm is only to ensure that the balance of sounds are right because at high revs the mechanical noise is very loud and this function makes sure that the induction sound is increased to maintain the balance.”

As for the burbling, cracking off-throttle sound of the engine and the exhaust, Hermann insists it is a backfire or misfire created intentionally by the engine management system by blending out cylinders and, he admits, it’s just “for fun”.

“We know the misfire does not match with fuel efficiency but this is for Sport mode and it’s for fun. We create it by blending out cylinders. It’s a very fast cylinder cut off.”

Yet the fuel saving is real. The original 911 consumed around 13L/100km, according to Porsche. This model sees the industry-wide explosion of engine start-stop technology make it into the 911 along with smart thermal management systems that see the engine warm up first, then the transmission and finally the coolant.

There is also an energy recuperation system that’s useful for topping up the battery in coasting or braking, but nowhere near a hybrid setup.

“We have done a lot of work specifically on fuel efficiency, and this shows across the board,” Porsche’s efficiency and energy management specialist, Dr Matthias Lederer, said.

“With the seven-speed manual transmission, for example, seventh is 19 per cent lower in the rpm than sixth, even though the top speed is set in sixth.

“This alone helps cut 10 per cent from the extra-urban fuel consumption, and the PDK is even better. The 997 Series II with PDK had 240 grams of CO2 ad this one has 194,” he said.

Even so, the 911's Body-in-White Development team leader, Lorenz Heinisch, pointed out that the 997 Series II S weighed1455kg, while with the new 991 series, the same variant is 1415kg.

The original Porsche calculations for what was needed to match the wishlists from the product guys added around 60kg (+29.6kg for occupant safety; +9.4kg for more equipment; +7kg for the longer wheelbase and, ironically, +15kg for fuel consumption measures), says Heinisch. Even so, the new car’s body-in-white is 80kg lighter than the old car.

“We saved 48kg by the way we used the aluminium/steel construction mix, then another 14.5kg for aluminium doors and we found 5.5kg in the interior, and another 3.6kg in the cooling system,” Heinisch claimed.

“If we had built it the same way as the old car it would have been 98kg heavier, which was obviously unacceptable.”

Once a largely steel car, the 911 has sprouted a front end that is almost all aluminium -- along with the front wings, the doors and the roof.

“We were forced to join aluminium and steel, but it was more difficult than that, because there were different thicknesses of steel and aluminium for different needs, along with different diecast [assemblies]," Heinisch explained.

To stop potential electrolytic corrosion adhesive is used wherever steel and aluminium meet, thus they are electro-mechanically separated.

More than 44 per cent of the 911’s body is now aluminium, but there is also plenty of steel, including 14 per cent of deep drawing steel (a soft steel for complex shapes) for the rear wings, roof frames, sills and windscreen base.

The body contains a range of different steels, rising in strength until it tops out at the16 per cent of ultra-high-strength boron-alloyed steels for the bulkhead, B-pillars and the inner roof frame.

There is also an Australian flavour to the 911's more technical bits. The 991's Mechanical Components team manager, Tobias Posch, saw a tour of duty at the factory-owned Porsche Centre Melbourne.

He singularly fails to understand either cricket or AFL but he does understand metal and how to use it.

“Let’s see: the aluminium doors are 15kg lighter and one of the trickier changes is that the spoiler is no longer integrated into the boot lid.... That means we could make it 60 per cent lighter in that panel and in a rear-drive, rear-engined car, that is gold.

“The spoiler is only 1.7kg and just 2mm thick and now we attach it to the body with four screws.

“It sounds strange, but the fuel flap is steel because it's the right material in the right position because it needs to be stiff enough that it does not bend or deform… If you did it in aluminium, the wall thickness would be too thick.

“The truth is that we consider steel light weight, but it’s not possible to achieve our weight targets with steel everywhere.”

It was a tough ask, with Porsche’s bosses after: ?5mm lower centre of gravity;? 45kg reduction  invehicle weight;? 2% reduction in the moment of inertia;? 4% reduction in drag; ?28% less aero lift;? 13% increase in bending stiffness; ?20% increase in torsional stiffness;? 100mm longer wheelbase ?and 46/52mm wide tracks (fr/rr).

The extra stiffness came courtesy of the body-in-white, but there are also completely new suspensions at both ends, new brakes, new dampers and, well, new everything. There is even a Sports version of the chassis that is aerodynamically more aggressive, with a steeper rear spoiler angle. Ride height is 20mm lower and the car is two seconds quicker at the Nurburgring.

The front axle is aluminium; there is a lighter aluminium front strut and the rear end is a five-link setup. Torque vectoring is standard on both 911s and Porsche claims there is less rolling resistance, but seven per cent more grip in both the wet and the dry.

There is a fully variable rear diff lock that works hydraulically to give between zero and 100 per cent locking. This works to counteract the agility-sapping characteristics of the longer wheelbase.

According to Porsche, the new car's lateral acceleration is up by 5.5 per cent; it stops a metre shorter from 100km/h; is five per cent quicker through a 36 metre slalom  and three per cent quicker in a high-speed lane change.

But two major changes have been the move to larger wheels and tyres and, critically, electro-mechanical steering.

“The steering of Porsche cars is pretty important,” Enderle admitted.

“There is still a rigid connection between the steering wheel and the wheel, but the system should be inconspicuous.”

While the Carrera S now runs on 20-inch wheels and tyres, the Carrera is on 19s, which has given Porsche both more grip and the ability to adjust the ride by changing the recommended tyre pressures depending on the work the car is doing.

“With the Carrera S, we used flow-formed alloys, because it gives higher material stiffness with thinner wall thicknesses. That’s good, because we have increased the wheel size but we don’t gain unsprung mass.” Enderle said.

“We wanted increased performance and comfort, but larger wheels give a certain height from the sidewalls and we have more possibilities with pressure.

"We can adjust the pressure by 0.3 bar [approx 5psi] for comfort and use that with up to 270km/h and then put more pressure in if you go to a track or at very high speed on the autobahn.”

Look out for more on the new generation 911 in coming weeks and our international first drive review on November 21.

2012 Porsche 911 Carrera

Engine: ?3436cc all-alloy flat six, 24-valves, direct injection, variable valve timing and lift
?Bore x stroke: 97 x 77.5mm
?Compression ratio: 12.5:1
?Max power: (claimed) 257kW @ 7400rpm
?Max torque: (claimed) -- 390Nm @ 5600rpm?

General?Mass (DIN): 1380/1400kg
?Gearbox: -- seven-speed manual / seven-speed PDK
?Dimensions (length/width/height): 4491/1808/1303mm?
Wheelbase: 2450mm?
Track: (f/r)  1532/1518mm
?Wheels: (f/r) -- 8.5 x 19/11 x 19
?Tyres: (f/r) -- 235/40 and 285/35 ZR19
?Fuel capacity: 64 litres

2012 Porsche 911 Carrera S

Engine: 3800cc all-alloy flat six, 24-valves, direct injection, variable valve timing and lift inlet
?Bore x stroke: 102 x 77.5mm?
Compression ratio: 12.5:1
?Max power: (claimed) 294kW @ 7400rpm?
Max torque: (claimed) 440Nm @ 5600rpm
?Max revs: 7800rpm

General?Mass (DIN): 1395/1415kg
?Gearbox: Seven-speed manual / seven-speed PDK
?Dimensions (length/width/height): 4491/1808/1303mm?
Wheelbase: 2450mm?
Track: (f/r) 1583/1516mm?
Wheels: (f/r) 8.5 x 20/11 x 20?
Tyres: (f/r) 245/35 and 295/30 ZR20?
Fuel capacity: 64 litres

Claimed performance
?0-100km/h: 4.4 seconds Sport Plus + PDK)
?0-200km/h: 16.2 seconds (15.4)?
Top speed: 289km/h?
Fuel consumption: combined 8.2 PDK

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