3.8-Litre Turbocharged – The 992 Turbo S Engine (2021)

The 992.1 generation Porsche 911 Turbo S is powered by a 3.8-litre six-cylinder engine. It is based on the 911 Carrera’s engine. The focus of development was to improve responsiveness, power, torque characteristic, emissions and revving ability. This has been achieved with new, larger VTG turbochargers in a symmetrical layout with electrically controlled wastegate flaps, a newly designed charge air cooling system and the use of piezo injectors.

Porsche 992 Turbo S Engine

The new six-cylinder engine features forced induction by a new intake system. For this purpose, the previous routing of process air and charge air cooling was swapped around. Part of the process air now flows through the characteristic Turbo air intakes in the rear side sections. In front of the air filters, which are now situated in the rear wings, two other airflows through the rear lid grille have now also been incorporated. This means the new 911 Turbo S has four intakes with a larger overall cross-section and lower wind resistance, improving engine efficiency.

Two symmetrical turbochargers with variable turbine geometry (VTG) and larger dimensions are also new. The compressor and turbine wheels now rotate in opposite directions; the diameter of the turbine wheels has been increased by 5 mm to 55 mm, while the 61 mm compressor wheel is now 3 mm larger. The wastegate flaps are electrically controlled with stepper motors, the advantage being that active and complete opening of the wastegates after a cold start means that the catalytic converters light off earlier. Boost pressure control is also faster and more precise.

Further downstream in the intake system, the compressed air flows through the two repositioned charge air coolers, which are now 14 per cent larger. They are located directly over the engine in a central position under the rear wing. This new position significantly improves their cooling efficiency and permits improved air inflow and outflow of the cooling air.

3.8-Litre Engine Technical Specifications

• Type: Six-cylinder boxer engine with VTG biturbocharging; gasoline particulate filter
• Cylinders: 6
• Valves/cylinder: 4
• Displacement: 3,745 cm³
• Bore: 102.0 mm
• Stroke: 76.4 mm
• Maximum power output: 478 kW (650 PS) at 6,750 rpm
• Maximum torque: 800 Nm at 2,500-4,000 rpm
• Compression ratio: 8.7:1
• Valve control: VarioCam Plus; variable valve timing on intake and exhaust sides, valve lift switchover on intake side
• Oil supply: Integrated dry sump lubrication and demand-controlled oil pump
• Turbocharging: Biturbocharging with variable turbine geometry (VTG) and electronically controlled wastegate; maximum boost pressure 1.55 bar
• Intake system: Expansion intake system
• Exhaust system: Exhaust system with two twin tailpipes mounted on rear section