Ascetic high-performance athlete
Engine and transmission
The heart of the new Speedster is the naturally-aspirated six-cylinder boxer engine with four-litre displacement, adopted from the 911 GT3. The fact that it is a pure and highly emotive GT engine is proven by its high-revving concept. The peak power of 375 kW (510 PS) is reached at 8,400 rpm, with the maximum engine speed at 9,000 rpm. The engine delivers the maximum torque – 470 newton metres – at 6,250 rpm. With an unladen weight of 1,465 kg, the power-to-weight ratio comes in at an extremely sporty 2.87 kg/PS. This guarantees a superior dynamic temperament: The new 911 Speedster accelerates from zero to 100 km/h in 4.0 seconds, covers the quarter mile (400 m) from standstill in 11.9 seconds and reaches a top speed of 310 km/h.
Compared with the previous 911 GT3, the engine in the Speedster is fitted with two gasoline particulate filters (GPF) and complies with the emission standard Euro 6d TEMP-EVAP-ISC. Yet the four-valve engine still manages ten PS more. This is due to numerous improvements to detail such as the high-pressure injectors with up to 250 bar injection pressure and optimised spray pattern as well as a modified intake system with individual throttle valves. This is characterised by a more spontaneous response to throttle commands.
Another new feature is the ultra-modern thin-wall exhaust gas system: this high-tech component benefits from innovative brazing technology and weighs ten kilograms less thanks to thanks to integrated front silencers and including both particulate filters. Particularly in the engine area, this weight reduction has a positive impact on the balance between the front and rear axles. At the same time, the exhaust system ensures lower emissions, sharpens the unmistakable engine sound and visually provides an unmistakable promise of a performance with its lightweight twin tailpipe – each pipe with a diameter of 90 millimetres.
The high-speed stability of the naturally-aspirated boxer engine is thanks to technologies that have been tried and tested by Porsche in motor racing. For instance, the rocker arms of the valves do without hydraulic valve clearance compensation. A fixed valve train with an adapted valve spring design – precisely adjusted to the engine speed and load by the VarioCam camshaft control – ensures stability even under tough conditions. The oil supply of the six-cylinder engine is also based on motor sports experience. The dry-sump lubrication uses a total of seven suction stages, while the oil pump ensures the optimum oil pressure for every operating condition. Highly-loaded components such as the connecting rod bearings are supplied directly from the oil pump via central oil supply into the crankshaft.
Transmission: manual shifting with automatic throttle blip
Befitting its status as an exceptionally dynamic sports car, Porsche only offers the 911 Speedster with a six-speed GT manual transmission. This delivers maximum driver engagement and offers a driving experience full of emotion. Compared with the Porsche dual-clutch transmission (PDK), the manual shift unit reduces the weight by approximately 17 kilograms and is a good four kilograms lighter than the seven-speed manual transmission in the 911 Carrera of the 991 series. This is due to omission of seventh gear as well as of the centrifugal pendulum on the dual mass flywheel.
The auto-blip function guarantees sporty gear changes. It compensates differences in engine speed when downshifting with targeted throttle blips and in this way reduces the influence of engine drag torque on handling to increase driving pleasure and improve safety. Another new feature is that the system can be activated at any time and independently from the PASM (Porsche Active Suspension Management) variable damping system. A mechanical rear differential lock with asymmetric locking action rounds off sporty power transmission.