Engine

The 4.0 TFSI in the Audi RS 7 Sportback delivers 441 kW (600 metric hp) and a constant 800 Nm (590 lb-ft) of torque across a wide engine speed range from 2,050 to 4,500 rpm. The high performance Sportcoupé will sprint from 0 to 100 km/h (0 to 62.1 mph) in only 3.6 seconds and will continue on to 200 km/h (124.3 mph) in just 12 seconds. The top speed is electronically limited to 250 km/h (155.3 mph). The optional dynamic package increases the top speed to 280 km/h (174.0 mph) or even up to 305 km/h (189.5 mph) with the RS dynamic package plus.

Larger turbochargers and an increase in boost pressure from 2.4 to 2.6 bar in the 4.0-liter V8 biturbo TFSI engine that the RS 7 Sportback performance boast, allow an increase of 30 PS in engine power and 50 Nm more torque compared to the base versions. This means a total increase in power from 441 kW (600 PS) to 463 kW (630 PS) and in maximum torque from 800 to 850 Nm. The performance model sprint from 0 to 100 km/h in 3.4 seconds, 0.2 seconds faster than the RS 7 base version.

The twin-turbo V8 engine has a conventional 90-degree bank angle and a displacement of 3,996 cc (bore x stroke: 86.0 x 86.0 millimeters (3.4 in x 3.4 in)). Its crankcase is made of cast aluminum and weighs just 39.1 kilograms (86.2 lb). The cylinder linings have been machined with the aid of atmospheric plasma spraying. This method involves applying an extremely thin iron coating to the cylinder linings. These coated cylinder linings improve heat dissipation, thermal and mechanical resilience, and wear resistance. They also significantly reduce internal friction and oil consumption. An electronic valve located centrally in the inside V also regulates the map-controlled piston spray nozzles as required for piston cooling.

A fully variable pump drives the oil system. It is split into two separate oil galleries – one for the engine block and one for the cylinder heads. This layout ensures a reliable supply of oil even under the extreme lateral and longitudinal acceleration that the Audi RS 7 Sportback* and the RS 7 Sportback performance* are capable of achieving. The variable water pump is only activated at 80 degrees Celsius (176 °F) so that the non-flowing coolant heats up quickly. The chains of the valve gear are driven by a geared intermediate shaft. It also drives the water pump. To ensure that the cylinders are filled optimally, intake and exhaust camshafts can be adjusted by 50 degrees. Each cylinder bank drives a high-pressure fuel pump that builds up pressure of up to 250 bar. The injectors, located in the center of the combustion chamber, inject the fuel through seven holes, following special injection strategies depending on the requirements, from cold start to full load. The firing order is identical to that of the predecessor engine: 1-3-7-2-6-5-4-8.

Powerful: Two twin-scroll turbochargers

The immense torque that the 4.0 TFSI produces even at low engine speeds and the extra 29 kW (40 metric hp) of output are all thanks to the two twin-scroll turbochargers. In addition to elevated boost pressure, the diameter of the compressor wheel in the turbocharger has been increased by 3 millimeters (0.1 in). Each turbo supplies a cylinder bank with up to 1.4 (relative) bar of boost pressure – 0.2 bar more than in the predecessor model. The higher boost pressure improves the volumetric efficiency of the cylinders, making more air available for fuel combustion. This results in higher engine power and improved efficiency. The cylinder heads have the intake side on the outside and the exhaust side on the inside. The larger turbos are located inside V of the cylinder banks rather than in the usual location outside next to the crankcase. This layout enables short gas flow paths with minimal flow losses and spontaneous engine response. Elaborate and effective insulation of hot components ensures thermally stable conditions inside the V. The compression ratio is 10.0 : 1 on the RS7 Sportback*. On the RS 7 Sportback performance* it is 9.7 : 1.

Efficient systems: Mild-hybrid and cylinder on demand (COD)

Thanks to its mild-hybrid system (MHEV) with a 48-volt main on-board electrical system, the 4.0 TFSI combines strong performance with high efficiency. The belt alternator starter can recover up to 12 kW of power under gentle deceleration and feed it into a lithium-ion battery as energy. If the driver releases the accelerator at a speed between 55 and 160 km/h (34.2 to 99.4 mph), the drive management will select one of two options. Depending on the driving situation and the settings in Audi drive select, the RS 7 Sportback* will either recover energy or coast with the engine switched off.

When the driver steps on the accelerator, the belt alternator starter will start the engine again. MHEV technology allows for start/stop operation at a speed of up to 22 km/h (13.7 mph). In everyday driving, it is possible to achieve fuel savings of up to 0.8 liters per 100 kilometers.

The cylinder on demand (COD) system is another measure onboard the vehicle that benefits efficiency. In higher gears at low to medium loads and engine speeds, it will switch off cylinders 2, 3, 5, and 8 by halting injection and ignition and closing the intake and exhaust valves. In four-cylinder operation, the operating points in the active cylinders are shifted toward higher loads in areas of the ECU map with higher efficiency, while the deactivated cylinders largely run without losses, like gas springs. They are reactivated immediately when the driver presses the accelerator. Each switchover takes mere milliseconds and is virtually undetectable by the driver and passengers.

The twin-turbocharged four-liter-V8 engine in the Audi RS 7 Sportback and the Audi RS 7 Sportback performance produces a full-bodied and sporty V8 sound. The driver can precisely influence the sonorous sound of the power unit via the Audi drive select dynamic handling system. The optional RS sport exhaust system with black tailpipe trim provides an even fuller sound. In the customizable RS1 and RS2 modes, customers decide themselves whether the sound should be sporty or balanced.

All terms marked in the text are explained in detail in the technology lexicon at www.audi-mediacenter.com/en/technology-lexicon.

The equipment, data and prices specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.