Despite the fact that many of the older 911s have often been seen as more legendary than some newer models, the 991, produced from 2011, has been universally appraised as one of the most advanced versions of the 911 ever. As usual, there are numerous versions of the car, with differing body styles and powering options, but the Turbo versions have been in the spotlight of the automotive enthusiasts ever since the 930 of the 1970s which changed the game for Porsche, putting it firmly in the company of the most extreme sports cars manufacturers in the world.
The 991 comes in two versions with forced induction. The first one is the 911 Turbo and the second one the 911 Turbo S. As you can imagine the S stands for a more powerful version and in this case it means that it has 40 hp (30 kW) more than the Turbo. But, GT Kraft can make the Turbo more powerful than the flagship Turbo S. They have two upgrade stages for the 991 Turbo. The first one already makes it more powerful than the Turbo S, reaching 602 hp (443 kW) and massive 803 Nm (592 lb-ft) instead of the stock 520 hp (382 kW) and 660 Nm (487 lb-ft). The second stage adds a new exhaust and a bit more power, separating the tuned 911 Turbo further.
From day 1 the 911 has been a proper example of a sports car that is incredibly distinctive when it comes to driving feel, very light and powerful and designed like nothing else. The RR layout made it almost unique and the use of the boxer engines with low center of gravity even more interesting to drive. Having in mind that it has been around for more than half a century it is no wonder that the 911 has endured loads of changes and tech developments, but each and every one of them has always been a proper example of the genuine Porsche philosophy. So what did 50 years of development bring us?
The 991. It is the latest version of the 911 and it has set a new benchmark for sports cars. The most powerful stock versions is the Turbo S with 560 hp (412 kW) and 700 Nm (516 lb-ft) of torque which goes all the way up to electronically limited 198 mph (318 km/h). The acceleration to 62 mph (100 km/h) is officially 3.1 seconds, but there have been numerous tests that prove the car can reach the milestone in as early as 2.6 seconds, far faster than most other cars with noticeably more power. How? Well, the unique layout, incredible balance, amazing drivetrain, weight reduction and the fact that it is a damn Porsche!
All this comes with a price. The car is almost $30k more expensive than the Turbo with 40 hp less. But is it really that much better? We could debate this, but there is a reason why it is pointless. You can opt for the Turbo and add just a bit more money and make it far more powerful than the Turbo S. You know what else? These power ratings stand for the non-facelifted version of the car, which can now be bought used for even less money. The facelift Turbo S comes with 580 hp, but the tuned early version of the 991 boasts even more horsepower.
As the subtitle says it, the stage 1 is consisted of SDI9 ECU software modifications and they give the mentioned 602 hp (443 kW) and 803 Nm (592 lb-ft) of torque. That is 82 hp more from stock parts alone. This was achieved by altering the software by following the original architecture of the OEM ECU and complying with the safe stress levels of the stock parts.
There are four alterations in the stage 1.
The first two go together, increasing the amount of air and gasoline in the air-fuel mixture. The extra air is provided by increasing the turbo pressure, while the second one comes from a change in injection, both of which are controlled by the ECU, so no new parts are needed.
The third step is a change in ignition timing, which helps burn the extra air and gasoline, by giving it more time, since the mixture ignites earlier. This also means that the throttle response is noticeably improved and that the car delivers the new horsepower and torque noticeably faster.
The last change is the icing on the cake and it is the removal of the top speed limiter that, even before tuning alterations, made the can a notch slower than 200 mph. After the removal and the power boost, 200 mph is no longer an issue. What more could you need? A new exhaust!
Yes, this is what the stage 2 Porsche 911 991 Turbo tuning adds. The exhaust comes from Akrapovic and it is lighter and more efficient when it comes to letting the gases out. This means that it shreds pounds, adds a new soundtrack and allows for a bit more of software fiddling, having in mind the easier gas releases. The result is about 15 hp more, but also more relieved engine and a proper preparation for the possible stage 3. It would bring a better turbocharger and that would up the power significantly, but also require further upgrades to the hardware, such as new intake, intercooler and maybe even injectors. This would make the tuned Porsche 991 Turbo the ultimate machine for the track and most certainly one of the fastest cars on the road today, since it is already the fastest 911 out there even when compared to the upgraded facelift model.