991.2 to be turbocharged

Every Porsche 911 to go turbocharged in 2015 with 991.2

Is nothing sacred? Zuffenhausen is preparing a facelift for the Porsche 911 family which will see the 991.2 generation launch in autumn 2015 with the majority of engines turbocharged.

Yes, the days of a naturally aspirated flat six are numbered, even for the venerable 911 range, the new issue of CAR magazine reveals.

The November 2014 issue, which went on sale this week, is led by a special preview of the important new cars arriving next year. In a special scoop dossier, European editor Georg Kacher discloses how the most basic 911s, the Carrera and Carrera S, will switch to forced induction.

What to expect on 2015's Porsche 991.2

Keen to reduce CO2 and increase mpg, Porsche is downsizing the Carrera's flat six by half a litre - from 3.4 to 2.9 in capacity. Our information suggests it'll develop around 400bhp and 400lb ft, a significant increase on today's boggo 911.

The 2015 Carrera S won't shrink in the hot wash, but its 3.8 boxer six will also be breathed on by a turbocharger, swelling power and torque substantially. Our sources suggest a punchy 530bhp and 520lb ft, meaning that even lower-peg 911s are getting seriously muscular.

Errr, so what does this mean for the 911 Turbo?

The mind boggles what this means for the more hardcore GT3 and GT2 models, let alone the Turbo - traditionally the only blown 911.

Our sources indicate the GT3 will remain naturally aspirated, with a greater focus on light weight; there's hope yet for old-school 911 fans.

Source , 991.2 to be turbocharged

Click to expand...

DRZ911 said:

Not sure of the accuracy of the original report, too many gaps and things do not add up.

Audi can already get 360 bhp out of their 2.5L TC 5-cylinder, so on this basis, am sure Porsche could manage at least 360bhp out of a 2.5 flat 6 TC engine and about 430 bhp out of flat 6 TC 3.0L. Would make more sense to reduce emissions and would be a logical step from where they are today with their 991.1 range without denigrating the top end 3.8 turbo family.

Click to expand...

tim993 said:

The regular cars could be 'light pressure turbos' - similar to the naming convention adopted by Saab when it produced turbo-charged non-sporty models...

just a thought :?

Click to expand...

rottenbend said:

Sounds like Ferrari are going to do the same thing with the 458 next spring. Something to do with Chinese taxes apparently.

NA engines are dying out in performance cars more's the pity. I've always preferred the noise, linear response and high rev range to turbo engines. You just don't get the same 3rd gear "long pull" in a turbo engine.

Click to expand...

Let's begin with the engine. Ferrari began the process of replacing the current naturally aspirated V8 back in 2008, spending much time and cash trying to create a turbocharged motor that would replicate the response, sound and free-revving nature if its atmospheric engines. Witchcraft, in other words.

There are two seats squeezed back thereThere are two seats squeezed back thereThe result is a 3,855cc V8, running 9.5:1 compression and two twin-scroll turbos. Nothing especially new there, and the turbos sit snugly on the sides of the motor, unlike BMW's clever positioning within the vee for reduced pipework length and therefore improved response.
There's some real trickery in the actual header and exhaust pipes though - they're all of equal length, to a tolerance of a few mm, and the turbine is sandwiched between three special castings that are then connected and bolted to the engine. It doesn't look cheap. But then again, there's nothing revolutionary here.

That comes in the engine calibration work. This motor is clearly capable of producing more torque than the rear axle can handle, but Ferrari has seen its best chance to replicate the feel of increased power and performance as the revs increase. We're now accustomed to people limiting the torque of these new turbo motors in the lower gears, but Ferrari has gone a step further and mapped each gear with its own individual torque curve. When you ask the team how long it took, they instinctively look into the double espresso to their right. Especially when you consider how connected the powertrain is to the complicated electronic differential and stability control systems.

Turbo trickery pays dividends on the roadTurbo trickery pays dividends on the roadSo this really is some trickery - artificially limiting the performance available in lower gears to give the sensation of needing to rev the motor out above 6,000rpm to enjoy peak power. It sounds a bit contrived because they've actually shaped the torque curve of every point in every gear to give the feeling they're looking for. The conundrum came in the higher gears, where they've chosen to let the turbines properly breathe, leaving the car with potentially similar roll-on acceleration in several gears.
To give the sensation of really hanging onto a gear, the ratios are much longer than before, with sixth now matching the old seventh, of course there's now enough torque to support such legs and the mapping allows surge to build as per a normally aspirated engine. The California T is just one great confidence trick, which had some of my colleagues in something of a froth, but if the results on the road make for a great drive, and the throttle response is good and the noise is proper Ferrari, I don't really see the problem.

There are other benefits. This motor is very compact with the crankshaft 110mm lower within the overall depth of the engine compared to the old N/A unit, and it sits lower too, the cumulative effect being a 30mm reduction is the centre of gravity of the motor. That's quite a lot. The claimed efficiency gains are 15 per cent in overall consumption, now up to 26.9mpg. I firmly believe that people who buy these cars don't care so much about consumption as they do range. The tank remains 78 litres and the test drivers say 300 miles between fills is about right.

Click to expand...