It has a 9000rpm rev limit. Let that sink in for a few seconds… With peak power developed at 8250rpm, the 3.8-liter flat-six in the new GT3 is the highest revving Porsche production motor ever built.
The 997 RS 4.0 had the last incarnation of the Metzger engine, and so a heavily tweaked version of the current 9A1 direct-injection flat-six motor takes the baton and runs with it in the 991 GT3.
A long list of lightweight reciprocating and rotating parts within the engine reduce inertia, while new manufacturing processes and coatings ensure robustness.
The big numbers are 475hp at 8250rpm, with peak torque of 325 lb-ft at 6250rpm. This equates to specific output of 125hp per liter in a car weighing 77 lb more than before, translating into a 0-60mph time of 3.3sec, terminating at 195mph.
With an open road in front of you, the new engine screams round the rev counter in the intermediate gears, while the brilliant seven-speed PDK transmission ensures the 475 able-bodied horses provide an uninterrupted push in the back.
The deep baritone roar from the twin central exhaust outlets is overlaid by a fearsome battle cry of induction, valves and high-lift cams running ever faster as they convert air and fuel into forward motion like never before in a road-legal naturally-aspirated Porsche motor.
Yet the most deeply impressive aspect of the new GT3 is the province of the seven-speed PDK, completely revised from its Carrera roots for this highly focused application.
Upshifts are so fast and seamless you just hear the motor drop its voice slightly while rapid forward motion continues unabated. The system also blips the throttle perfectly going down the ‘box, making you sound like a racer to onlookers.
Importantly, should you choose to use the gear lever instead of the paddles, the shifter now works correctly in manual mode; forward for a downshift and vice versa.
In addition, aspects of an automatic inappropriate to a hardcore sportscar have been edited out. One is kickdown, the other is the tendency to shift down if you short-shift, but then go to full throttle, giving you control over your gear selection.
The purists are screaming from the rooftops about the manual gearbox being the last connection between the car and driver, but Porsche now considers them relics of a bygone era. In fact, GT model chief, Andreas Preuninger told us the PDK was only chosen late in the development and, as a purist, he had to be personally convinced beyond doubt.
During an in-house test it emerged that the dual-clutch trans was worth 4sec per lap on the Nürburgring, which is substantial. Ultimately, the GT3 is about going fast, and PDK makes it faster, period.
To underline its superiority against the stopwatch, Porsche test driver, Timo Gluck, recently set a benchmark time of 7min 25sec on the Ring – 7sec faster than both the 530hp twin-turbo 997 GT2 and legendary Carrera GT. It’s also 2sec faster than the outgoing 500hp GT3 RS 4.0, and 6sec better than its RS 3.8 predecessor. And the 991 GT3 lap time was achieved with a 475hp production engine powering the 3152 lb car.
However, none of that extra weight is in the wrong places, with the extra 44 lb of the PDK compensated for by removal of a similar amount from the engine.
The PDK Sport button on the center console is tempting, as is the firmer setting for the PASM active damping, but are best left for the racetrack. Sport is generally too trigger-happy for public roads and the firmer suspension is normally appropriate for smooth roads or the racetrack. However, it also activates the dynamic engine mounts that tighten for optimum cornering.
When you turn the GT3 steering wheel you notice it’s by far the best iteration of the 991’s electric power steering, moving the car with unerring balance and stability. It benefits from electro-mechanical rear-wheel steering that allows the rear wheels to move about 1.5˚, shortening the effective wheelbase at low speeds for increased manoeuvrability, and lengthening it for enhanced stability when you gain pace.
Under 30mph the system moves the rear wheels in the opposite direction from the steered fronts, making the car more agile at parking speed.
Above 50mph, the rear wheels turn in the same direction as the steering, pre-loading the rear tires and removing their latency, where the rear usually takes longer to follow the front.
On the road, you don’t feel anything different and, should the sensors identify you’re intentionally drifting the car, it will actually help you here too.
As was discovered during high-speed testing at Nardo in Italy, another advantage of the rear-wheel steer is lower tire wear since they don’t work so hard.
While the rear-wheel steering system is a significant factor in the GT3’s faster lap times, the new variable-ratio limited-slip diff also contributes to handling consistency. It apportions traction to the individual rear wheels with greater accuracy than before, allowing an open diff on the overrun for improved stability.
Extra stability at speed is conferred by a 20% increase in downforce, or 265 lb at 125mph, with a drag coefficient of 0.33.
The damping is simply superb, absorbent at low speeds but anchoring body movement when you’re pressing on. In fact, it rides better than a regular Carrera – no mean feat when the GT3 sits on 20x9" and 20x12" forged wheels shod with 245/35 and 305/30 track-day rubber. These are the latest generation Michelin Pilot Sport Cup 2 tyres in a Porsche-specific compound.
The new 911 GT3 may be a road-legal homologation special and the best driver’s 911 ever, but it’s docile enough for daily use and throws the dynamic shortcomings of more expensive supercars into stark focus. It’s a stern warning to other carmakers that “exotic” is no longer an excuse for faults.
2014 Porsche 911 GT3
Layout rear-engine, RWD
Engine 3799cc flat-six, four overhead cams, 24v, direct injection, VarioCam variable valve timing, dry sump
Drivetrain seven-speed PDK dual-clutch transmission, electronic LSD
Brakes six-piston calipers f, four-piston r, 380mm PCCB ceramic rotors f&r
Suspension McPherson strut f, multi-link r, PASM active dampers, rear-wheel steer
Wheels & Tires 20x9" f, 20x12" r forged center-lock wheels, 245/35 ZR20 f, 305/30 ZR20 r Michelin Pilot Sport Cup 2 tires
Exterior aluminum bodywork, GT3 front splitter, fixed rear wing, engine cover with ram intake
Interior Recaro seats, alcantara and leather trim
Max power 475bhp at 8250rpm
Max torque 325 lb-ft at 6250rpm
Top Speed 195mph
Weight 3152 lb