Porsche unleashes the fifth gen 911 GT3

THE PORSCHE 911 GT3
photos by Daniel Wollstein


Back in 1999 no one knew what the 911 GT3 really stood for. Could it be the reincarnation of the revered RS line? Or was it merely one of the numerous model variants that Porsche has become famous for? There was a hint that Porsche wanted to homologate this model for GT3 racing but this was not a lightweight model. Indeed it was even heavier than the 911 Carrera and besides Porsche had become more interested in GT2 racing. Only three years later was it revealed that the 911 RS lineage would continue but it would be part of the GT3 line and not the Carrera as it was previously.

This is probably a result of rationalizing the RS Clubsport and RS Touring models in the original RS concept where Porsche found that many who ordered the RS Touring also refitted deleted weight bearing items like air-conditioning and power windows. So the GT3 was still a Motorsport designed model now built on the production line rather than re-working finished 911s at Weissach like they did for the air-cooled RS cars. The GT3s also came with all the luxury items of the Carrera line.

Not having planned for huge volumes the first GT3 sold out quickly and left many clamouring for more after initial reports of its greatness. Only after two long years the second version of the 996 GT3 appeared (now also for US market) using the 996 Turbo front lamps and a new, less elegant rear wing. It too sold out quickly and toward the twilight of the 996 model life the GT3 finally got the RS version. After finding this formula was successful, Porsche developed the 997 GT3 and GT3 RS in quick succession after the initial introduction of the 997 range and this pattern was repeated with the second version of the 997 GT3.

Visually the GT3 does not disappoint with a new rear wing and front splitter creating a full update of the GT3. And while the front splitter and rear wing look fabulous, they are there for function not style though many would buy them for style alone. Its rakish new lines is befitting a product coming from the Motorsport department and together these aero aids increase downforce to 122 kg at 300 km/h compared to the 997 GT3 which had 103 kg. They also managed to keep drag at 0.33. The full width aero wing of the GT3 RS 4.0 has more downforce at 190 kg but the new GT3 does not need so much downforce as there are several technical tricks that add to the GT3's newfound capability.

On the inside the cabin has not been stripped down to save weight but one can have the Clubsport seats and rollcage (and extinguisher) as a no cost option. Apart from the deletion of the rear seats the cabin is like any 911 save for the GT3 badging on the instruments, seats and rear carpet. You can also have colour coded seat belts as well to match the car's exterior.

Without the special Mezger engine it is interesting what solution Porsche would come up with. The normal production engine has been updated a few times to the point it could produce over 500 bhp safely in the 997.2 Turbo S but what concerned us was max revs which happens to be a happy 9000 rpm in the new GT3. The cylinder heads and crankcase are pure Motorsport parts with dry sump lubrication and special rocker actuated valve train to speed up valve lift and also save weight. There is a user selectable sport exhaust system allows for an EU regulation noise level or a more straight through path with the attendant sports soundtrack. Sport mode raises both power and sound levels.

Something else has changed apart from the styling as the GT3 has been moved from the niche model to mainstream model. Motorsport has declared that try as they might, they acknowledge lighter is not always equal to faster, possibly alluding to the high-tech challenge posed by the much heavier Nissan GT-R at Nordschliefe. Some electronic wizardry is needed to whittle down those lap times.

One of those controversial devices is something already in use, the PDK. We of course knew that day would come but we did not expect them to completely drop the manual gearbox, even from the options list. To make this more palatable, Andreas Preuninger, head of Porsche Motorsport took pains to explain the need to shift to PDK. To cut a long story short, its all about quickest lap times and the PDK is better at that than a manual box. But of course the marketing boys are gleefully smiling in the background as this will attract far more sales than a manual gearbox.

In mitigation Preuninger has directed his team to make sure this is no ordinary PDK box. For sure this is no racing gearbox because the Cup car uses a racing sequential gearbox but both also feature paddle shifters and not the long sequential lever shifter. This allows both hands to be at the helm as Timo Kluck, Porsche test driver attests to as he set the times for both the last RS 4.0 and the new GT3. He managed to lop off two seconds to an already quick 7 min 27 seconds in the RS 4.0, a car with 500 bhp, a lot more downforce and 60 kg lighter than the new GT3. There is obviously more to this than meets the eye.

For sure the PDK with its 100ms shifts contributes to this advantage as there are a lot of shifts during a (Norsdschleife) lap and if each is shortened by 100 ms this quickly adds up(note only half are power upshifts). The gear ratios are also lower to the point the overdrive 7th gear is now almost a direct drive ratio topping out at 9000 rpm at 315 km/h. The closely stacked gears now deliver more torque at any speed when driven on the track.

But this PDK had to be special so the engineers have also added a unique “paddle neutral” feature that allows operation like a dropped clutch manoeuvre, an essential skill set used by drifters to kick the tail out. Hold both paddles and the clutch opens and engine revs rise to a limited 6000 rpm. Release both paddles and the clutch bites and turns the huge 305/30 ZR 20 Michelin Super Sport 2 gumballs into expensive smoke. The Sport launch control is more gentle only allowing 2m of black lines whereas the paddle neutral drop clutch start will draw lines for nearly 15m. Test driver Timo just shrugs and says, “These Michelins just hook up so soon” like he can't get enough of tyre smoke. Normal launch control is the kindest to the tyres where the electronic nanny doesn't even allow a chirp.

For the first time Porsche Porsche is using an E-Diff in its GT3 supplanting the mechanical LSD one before. This boosts the capability to deliver even more power to the tarmac exploiting the wheel with the most grip to the fullest where the mechanical locking diff only could deliver half to any wheel. The capability to divert all or most to one side also opens up the possibility of torque vectoring to the PSM.

The active anti-roll that helped the Carrera S grip like a leech has been thrown out in favour of a new approach, active rear-wheel steer. This is not a new idea but new for Porsche Motorsport. Firmer springs and a lower center of gravity provides better roll resistance and the conventional anti-roll bars went back in for a more natural handling behaviour at the limit that enthusiasts understand better.


The new Rear Wheel Steer system uses electro-actuators that above 80 km/h begin to steer in the same direction as the fronts up to 1.5 degrees and as a by product of this ability the actuators can counter steer below 50 km/h to reduce the turning circle. Though it adds 6 kgs this system reduces the nervousness of the 911 at high speed by giving it a virtual wheelbase increase of nearly 500mm, reducing yaw at high speeds. Also this reduces rear tyre temperature during track use and keeps the rears running longer and safer.

One of our complaints of the 991 was the new Electric Power Steering system but for the GT3 it has been overhauled and while the hardware is the same, the Motorsport engineers have rewritten the software algorithms so that the EPS now feels like the old hydraulic servo ones of the 997 RS which is to say excellent and a far cry from the normal Carrera. Surely this will be applied to Carrera models in future as it is just software. It does mean the steering writhes more in your hands and this are the nuances enthusiasts crave for on any drive.

With each passing version of the GT3, the Motorsport engineers have been improving both ride and handling. When they started with the 996 GT3 the ride was a bit knobbly and the handling was a little on the nervous side but it was still a real ball of fun, something special. The second GT3 smoothened out the nervousness with a new variable ratio steering that has stayed with the 911 ever since. The move to Michelin Pilot Sport 2 also helped. The breakthrough GT3 came with the early 997 version when they began to use PASM that allowed a much broader range of damping than the fixed rate type. Since then they have been slowly moving the game on but always expanding on the handling side more than the ride which we already regard as one of the best in the sportscar genre.

The use of rose joints or spherical rod ends has been a staple for race cars for a long time but when we tried it for the first time in the 997.1 GT3 it was a total relevation for it was comfortable and noise free. Also for the first time the fixed rate adjustable suspension was replaced by Porsche Active Suspension System (PASM) but these PASM dampers are not the same ones found in the Carrera as Bilstein has built them specially for the GT3 suspension system that features adjustable ride height, spring preload, castor and camber adjustment. Thanks to the dedicated spherical rose joints the geometry is kept in perfect check without any unnecessary movement whatsoever. Porsche Motorsport have developed a suspension that has the remarkable ability to filter out high frequency harshness yet provide supreme control.

Conclusion

Of course Porsche is concerned with the acceptance of a non-manual purist car like the GT3 but they actually baited us at the end of the 997 era with the 911 GTS. Think about it, it has a production engine with power lifted by 23 bhp to 408 bhp, just shy of the 435 bhp of the 997 GT3. But it had a PDK and a “Motorsport inspired” suspension (Motorsport claims it had nothing to do with the GTS). This run-out model sold out quite easily and proved the marketing concept would work well. Curiously they offered both manual and PDK unlike the GT3 but hopefully the Yanks will have something to say about that.

Selling about 2000 GT3s each generation might be a boon to collectors or enthusiasts but for Porsche its just too few. Even combined with the RS version which nearly doubles the total is only scratching the surface of the GT3's sales potential. Now that it has PDK to go with the GT3 credentials it is poised for vertical take off.


SPECIFICATIONS
DRIVETRAIN
TYPE Flat Six, 24-valves
CAPACITY 3799cc
BORE X STROKE 102.0 mm x 77.5mm
COMPRESSION RATIO 12.9:1
MAX POWER 475bhp at 8250rpm
MAX TORQUE 440Nm at 6250rpm
POWER TO WEIGHT 332.2 hp per tonne
GEARBOX 7-speed PDK dual clutch
DRIVEN WHEELS Rear
PERFORMANCE
0-100KM/H 3.5 seconds
TOP SPEED 315 km/h
CONSUMPTION 7.81km/L (combined)
CO2 EMISSION 306g/km
SUSPENSION
FRONT Double wishbones, springs and active dampers, anti-roll bar
REAR Double wishbones, springs and active dampers, anti-roll bar
BRAKES
FRONT / REAR Ventilated carbon-ceramic discs (option)
TYRES
TYPE Michelin Super Sport 2
SIZE 245/35 R20 (front)

305/30 R20 (rear)

SAFETY
AIRBAGS 4
TRACTION CONTROL ABS with PSM, PTV
MEASUREMENTS
LENGTH 4545mm
WIDTH 1852mm
HEIGHT 1269mm
WHEELBASE 2457mm
KERB WEIGHT 1430kg
TURNING CIRCLE 11.1m
 

 

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