911 Turbo

Performance

The location of the six-cylinder boxer engine was not up for discussion. Neither was the use of two exhaust gas turbochargers with Variable Turbine Geometry (VTG). These are permanent fixtures in a successful concept. But that was no reason for Porsche engineers to rest on their laurels.

As a result, the 3.8-liter flat-six engine now comes in two power levels.

The 911 Turbo models generate 500 hp at 6,000 rpm and 480 lb.-ft. of torque between 1,950 rpm and 5,000 rpm (516 lb.-ft. for a temporary period with the overboost of the optional Sport Chrono Package Turbo with dynamic engine mount system).

In the 911 Turbo S models, a modified valve control system and an adaptation of the engine management, combined with an increase in maximum boost pressure by around 2.9 psi, enable the power unit to produce 530 hp between 6,250 rpm and 6,750 rpm and generate a permanently high torque of 516 lb.-.ft between 2,100 rpm and 4,250 rpm to deliver even more power to the road.

The consistently high low-end torque of both engine variants means that you can relax behind the wheel – and relax about fuel consumption, too.

Fuel consumption is a consideration that at present is becoming at least as important as performance figures. Including – perhaps particularly – for sports cars of this genre. The fuel consumption and emissions of the 911 Turbo S models are as low as those of the 911 Turbo models, despite 30 hp of extra power output. Despite the extra power, it has been possible to increase fuel efficiency.

This has required the use of sophisticated technologies and processes. Examples include direct fuel injection (DFI), VarioCam Plus, Variable Turbine Geometry (VTG) and the expansion intake manifold.

On balance, the engines of the 911 Turbo and 911 Turbo S models demonstrate power, even when it’s not just about power in the traditional sense of the word.

Direct fuel injection (DFI)

On the 911 Turbo models, DFI injects the fuel with millisecond precision directly into the combustion chamber at up to 2,030 psi via electromagnetically actuated injection valves, thus ensuring homogeneous distribution of the air/fuel mixture and consequently efficient combustion.

In the direct injection system, the EMS SDI 3.1 engine management system adjusts the injection timing individually for each cylinder and the injection quantity for each cylinder bank. This optimizes both the combustion curve and fuel consumption.

Dual injection is implemented at engine speeds of up to 3,200 rpm and triple injection up to 2,700 rpm to ensure faster catalyst warm up after a cold start and more torque in the upper load range. The required quantity of fuel is distributed to two or three successive injection processes per cycle.

DFI improves the internal cooling of the combustion chamber by forming the mixture directly in the cylinder. This has made it possible to increase compression (9.8:1), resulting in more engine power and even greater efficiency.

Lightweight design

An alloy engine means less weight and consequently reduced fuel consumption. The intelligent engine design also saves weight.

The alloy crankcase is divided vertically, with the cylinders integrated into the crankcase. Forged connecting rods are used. For optimum durability, we’ve used forged aluminum pistons running in cylinders made from an aluminum/silicon alloy and cooled via individual oil-spray jets.

Integrating the camshaft bearing system fully into the cylinder heads has also saved weight. The subsequent low levels of engine friction and the efficient design of the oil supply system have helped to reduce fuel consumption even further.

Engine management

The EMS SDI 3.1 engine management system ensures optimum performance at all times.

It is responsible for all engine-related functions and assemblies, resulting in improved fuel economy, emission levels and performance, regardless of driving style.

Another important task performed by the engine management system is cylinder-specific knock control. Since conditions tend to vary across the engine, each cylinder is monitored separately. If a risk is detected, the individual ignition timing is adjusted to protect the cylinders and pistons at high engine speeds and loads. The on-board diagnostics system provides continuous fault detection as well as early warning for the exhaust and fuel supply systems. This actively reduces harmful emissions while maintaining consistent rates of fuel consumption.