Porsche again sets a new high-performance standard The new 911 GT3 brings innovation to the street
The 911 GT3 brings out the Porsche DNA in its rawest form, and embodies the “Idea 911” wholeheartedly. The all-new high performance sports car offers both performance and efficiency, as well as driving enjoyment and practicality at an entirely new level.
A wealth of technical innovations preserves the original and direct driving experience while combining it with enhanced driving dynamics. The first active rear-wheel steering in a production Porsche plays an essential part here, resulting in an entirely new, even more emotional GT3 feeling.
The new 911 GT3 is based on the current 911 Carrera series. However; engine, transmission, and chassis have all been further developed and in some cases bring a radical departure from other 911 Carrera models.
The two-seater is powered by a 3.8-litre six-cylinder boxer engine with direct petrol injection for the first time, producing 350 kW (475 hp). Although the engine is based on the 911 Carrera S engine it shares only few common parts. Many components, particularly the crankshaft and valvetrain, are specially adapted or developed for the GT3. For example, Porsche is once again using titanium connecting rods and forged pistons. These modifications set the stage for an extremely high 9,000 rpm rev limit.
The 911 GT3 breaks more new ground by coming standard with a new seven-speed Doppelkupplung PDK manual gearbox – with characteristics inspired by sequential gearboxes used in motor racing. It is extremely responsive and now with shorter gear ratios to maximise acceleration. This 911 GT3 now sprints from zero to 100 km/h in 3.5 seconds on its way to a 315 km/h top speed.
The use of active rear-wheel steering for the first time on the new 911 GT3 brings further gains in handling precision and lateral dynamics. Depending on road speed, the system steers in the opposite or the same direction as the front wheels, to improve agility and stability.
Among other new dynamic driving features are the electronically controlled, fully variable rear differential lock and dynamic engine mounts. The height, toe and camber of the newly developed all-aluminium chassis are still adjustable. The new, 20-inch forged alloy wheels with single central locknut now permit larger tyres and in turn more mechanical grip.
Traditionally, the 911 GT3 comes as a two-seater based on the lightweight body of the current-generation 911 Carrera. However, the front and rear body sections are always model-specific. The 911 GT3 therefore features a rear body section that is 44 mm wider than the Carrera S. Another clear identifying feature is the large, fixed rear wing. This makes a decisive contribution to the exemplary aerodynamics of the new 911 GT3, which combines low air resistance with a further increase in so called ‘negative lift’.
As a result, the new 911 GT3 once again resets performance benchmarks. In addition to reaching 100 km/h from standstill in just 3.5 seconds, the 911 GT3 eclipses 200 km/h in less than 12 seconds. The 315 km/h top speed is reached in seventh gear – top gear – of the PDK transmission. And the lap time on the famed Nurburgring Nordschleife is even more impressive: the new 911 GT3 cracking the 7 min 30 sec mark.
Completely new: Sports engine with high-revving concept
The Porsche Motorsport Department has an entirely new engine for the 911 GT3. This engine is a synthesis of the previous GT3 high-performance engine (the potential of which had been largely exhausted) and the new engine generation of the current 911 Carrera series. For instance, the new engine comes with typical motorsports characteristics, such as dry sump lubrication, high-revving power and titanium forgings.
These are combined with cutting-edge technologies of production engines such as direct petrol injection, demand-controlled oil pump, and lightweight design and materials. As a result the new engine weighs around 25 kg less than its predecessor and a phenomenal displacement of 125 hp / litre (92 kW / litre).
Much of the focus of the new engine is the cylinder heads, which differ fundamentally from those of the base engine, and were specifically developed for the 911 GT3. To enable peak performance values and high rpm, the new cylinder heads are equipped with large intake and exhaust ports, large valves, and separate valve control with rocker arm. Cooling and oil supply are also at optimum settings to account for the high loads.
The valve actuation via rocker arms with hydraulic valve clearance compensation is another unique feature. The concept embodied in the 911 GT3 engine originates from racing and allows very high engine speeds on one hand, while the other cams with performance oriented profiles permit a larger stroke and long valve opening time.
More power and efficiency: the first GT3 engine with direct petrol injection
Porsche has opted for a 911 GT3 engine with direct petrol injection for the first time.
Compared to the previously used conventional manifold injection, this technology has proven itself in Porsche’s road-going sports cars, since it permits higher power and torque, as well as yielding higher efficiency and lower CO2 emissions.
In the 911 GT3 engine this technology has been developed further, specifically with performance in mind. That's why the new high-performance sports car comes with a specially developed injection system with multi-hole injectors and significantly higher injection pressure. Compared with the swirl injectors of the 911 Carrera models, multi-hole injectors provide a larger usable range of fuel quantity injected.
The new 911 GT3 now includes a more advanced generation of the previously optional dynamic engine mounts, which have been further optimised in the 2014 model.
And as was the case with its predecessor, the new 911 GT3 also offers the driver the possibility to increase low to mid range torque at the press of a button. When activated, the back-pressure in the sports exhaust system is further reduced, improving gas exchange and thus increasing the torque in the 3,000 to 4,000 rev range by up to 35 Newton meters.
PDK: returning to the race track
The dual-clutch Doppelkupplung (PDK) transmission originates from Porsche racing. With the 911 GT3, it returns to the racetrack: The motorsports engineers in Weissach have revised the PDK extensively both in terms of mechanics and control technology. The driver now gains all the essential driving dynamics of the previous manual transmission but with the performance benefits of the dual-clutch transmission. On the race track it can be driven much like a sequential manual gearbox – with even more performance and driving fun.
Two modes are available to the driver: manual shifting or the adaptive shift programme. Manual shifting is done through the two paddles on the steering wheel, the left for upshifts and the right for downshifts. Shorter shifting travel and optimised actuating force result in even faster gearshifts, similar to the operating characteristics of the 911 GT3 Cup race cars.
Alternatively, the driver can also shift using the selector lever, with a shift pattern based on that used in professional motor sports: shifting up is done by pulling the lever back, shifting down by pushing it forward.
Gear shifting strategy and response times of the 911 GT3 PDK are designed for maximum performance and are therefore fundamentally different to the other Porsche sports cars using PDK. This becomes apparent to the driver during manual upshifts in the form of a “lightning shift", which permits reaction times of less than 100 milliseconds.
However, for the first time, PDK also allows the driver of the new 911 GT3 to leave the gear shifts entirely to the adaptive transmission control.
The PDK of the new 911 GT3 only comes with two switching strategies: Sport and Race Track. This means that the gear changes of the new 911 GT3 are always fast.
Even faster lap times: 911 GT3 with new rear-wheel steering
Just as much as the engine, the chassis of the new 911 GT3 combines the strengths of the previous design with those of the current 911 Carrera chassis. The extended wheelbase and wider track improve the footprint, thereby increasing both longitudinal and transverse stability. All development had only one goal – increase driving dynamics even further. That's why Porsche has extended the performance package of the 911 GT3 with yet another new feature – active rear-wheel steering.
The system comprises two electro-mechanical actuators, which are used at the left and right side of the rear axle instead of the conventional control arms. These allow the steering angle of the rear wheels to be varied by up to about 1.5 degrees, depending on road speed. At speeds of up to 50 km/h, the system steers the rear wheels into the opposite direction of the front wheels. The 911 GT3 enters the curve faster; permitting more dynamic cornering. The virtual shortening of the wheelbase by around 150 mm also results in significant improvements in agility and everyday usability, the turning radius is reduced, and maneuvering and parking become much easier.
At speeds above 80 km/h, the system steers the rear wheels parallel to the front wheels. This results in a geometric virtual wheel extension of about 500 mm, thereby increasing stability, particularly at high speeds.
Independent all-aluminium chassis lowered by 30 mm
The chassis of the new 911 GT3 is a largely new design based on the chassis of the 911 Carrera, but now 30 mm lower than its predecessor. The variable PASM damping system with two pre-selected specially tuned maps is part of the standard equipment, as was the case previously.
The multi-link rear axle was also largely developed from scratch for the new 911 GT3. Again, independent wheel mounts and wheel hubs, as well as larger mounts, result in increased stability and strength. The subframe, including side panels and control arms, are exclusively made of hollow aluminium casting, which brings about a weight saving of around 3.9 kg, as well as increased strength. The rear axle now also uses a spring-damper element with a so-called helper spring.
The rear axle of the new 911 GT3 is equipped with the Porsche Torque Vectoring Plus (PTV Plus) as standard. The system, which was adapted specifically for the 911 GT3, consists of an electronically controlled, fully variable locking rear differential and selective braking interventions at the rear wheels. In combination, these features provide high traction on changing road surfaces, an improvement to lateral dynamics, more precise cornering, and increased driving stability.
The wheels, also a clean sheet design, round off the package of measures that further improve driving dynamics. Compared with the 19-inch wheels of the previous GT3, the new 20-inch GT3 wheels are not just one inch bigger, but also half an inch wider at the front. The tyres on the front axle are also wider. The new 911 GT3 therefore rolls on 20x9J wheels with 245/35 ZR 20 rubber on the front, and 20x12J with 305/30 ZR section rubber on the rear.
Quintessentially Porsche: In the new 911 GT3, more dynamic driving performance goes hand in hand with further improvements in braking performance. At the rear axle, larger braking discs with a 380 mm diameter are used, the ventilation holes of the discs have been redesigned, and cooling is improved by ways of additional brake cooling ducts on the rear axle. To reduce unsprung weight, the new 911 GT3 comes with racing-derived composite brake discs with friction rings made of cast iron and aluminum pots, just like its predecessor. The two components are still connected by stainless steel pins.
The body of the new 911 GT3 is a development based on the latest 911 Carrera. The extensive use of aluminum in the front and rear body, as well as the floor assembly, reduces the shell weight by around 13 per cent over the previous model. Roof and wings, rear boot lid and doors are also made of aluminum alloy. In addition, the torsional rigidity is increased by about 25 per cent. Both factors become immediately apparent when it comes to vehicle dynamics.
The front apron is newly designed for the new 911 GT3. In addition to the integration of the new front lights, the larger apertures improve air supply to the radiator compared to the 911 Carrera.
The distinctive identifying feature of the rear of the new 911 GT3 is its boot lid with fixed wing. The completely newly developed rear boot lid is made of a composite material consisting of glass and carbon fibre. Wing supports, the large ram-air intake for the air supply of the engine, and the spoiler lip are all integral components of the design.
Limited numbers of the all new 911 GT3 will go on sale in Australia late in the year. Pricing is not finalised and will be announced closer to launch.