Twin-turbo refers to a turbocharged engine on which two turbochargers compress the intake charge. A turbocharger, or turbo, is an air Compressor used for forced-induction of an Internal combustion engine. The internal combustion engine is an engine in which the Combustion of Fuel and an Oxidizer (typically air occurs in a confined space called a There are two commonly used twin turbo configurations; parallel twin-turbo, and sequential twin-turbo. A third kind of twin-turbocharging called staged turbocharging exists, but is used more in diesel racing applications, and not road cars. Diesel or Diesel fuel (ˈdiːzəl in general is any Fuel used in Diesel engines The most common is a specific fractional distillate of petroleum
Contents |
Parallel twin-turbo
Parallel twin-turbo refers to a turbocharger configuration in which two identical turbochargers equally split the turbocharging duties. Each turbocharger is driven by one half of the engine's spent exhaust energy. In most applications, the compressed air from both turbos is combined in a common intake manifold, and sent to the individual cylinders. Both turbos function simultaneously, unlike sequential twin-turbos. Commonly each turbocharger is mounted to its own individual exhaust/turbo manifold, however on inline-type engines both turbochargers could be mounted to a single turbo manifold. Parallel twin turbos are usually applied to V-shaped engines where one turbo is assigned to each cylinder bank, providing packaging symmetry, and simplifying plumbing; however, it is not uncommon for a parallel set-up to be used on an inline engine. Nissan's RB26DETT is an inline-6 that uses a twin-turbo set-up, as is BMW's N54. The RB engine is a 20L to 30L Straight-6 four-stroke Gasoline Engine from Nissan. The straight-6 or inline-6 engine (often abbreviated I6 or L6) is a six cylinder Internal combustion engine with all six cylinders The N54 is a twin - Turbocharged Straight-6 Automobile engine from BMW. Toyota's 1992 Supra with the 1JZ-GTE (Japan only) 6 cylinder inline engine also used this same configuration, as does Volvo's 1998-01 2. This article is about Volvo Group - AB Volvo Volvo Cars is the passenger vehicle maker owned by Ford Motor Company, using the Volvo Trademark 8L B6284T and 2002-06 2. 9L B6294T straight-six engines in the 1998-2006 S80 T6 and 2003-05 XC90 T6, Nissan's 1990-1996 Z32 300ZX with its V6 VG30DETT. The Volvo S80 is a high-end Executive car produced by the Swedish automaker Volvo and was introduced in 1998 as a replacement for the Rear-wheel The Volvo XC90 is a Mid-size luxury Crossover SUV produced by Volvo Cars since it was unveiled at the Detroit Motor Show 2002 Audi's 1997-2002 S4 (B5), 1997-2004 A6, and 2003-2004 RS6 are examples of a parallel twin turbo implementation where each turbo is driven by one bank of cylinders, as the motor in each is in a V formation. AUDI AG, ( Xetra: NSU commonly known as Audi (aˈʊdi is a German Automobile manufacturer which produces Audi branded cars with headquarters The Audi S4 is a high performance sport version of the Audi A4 range of cars. The Audi A6 is an Executive car produced by the German Automaker Audi. The Audi RS6 quattro, commonly referred to as the RS6, is the highest performing version and top-of-the-line specification of the Audi A6 (positioned above the
While a parallel twin-turbo set-up theoretically has less turbo lag than a single turbocharger set up, because of marginally-reduced combined inertial resistance, and often simplified exhaust plumbing, the fact that both turbos spool at more or less the same time means that there is still a noticeable bit of lag, especially in high-flow turbo/high boost applications. A turbocharger, or turbo, is an air Compressor used for forced-induction of an Internal combustion engine. One way to counter this is to use a light pressure set up where the turbos are designed to output less boost but spool earlier, however, this set up sacrifices top end power. Another system would be the use of variable geometry turbochargers, this system changes the angle of the guide vanes depending on the exhaust pressure giving the system excellent power throughout the rev range. Variable geometry turbocharger s ( VGT s are a family of Turbochargers usually designed to allow the effective Aspect ratio (sometimes called A/R Ratio of Once used mainly in turbocharged diesel engines, Porsche was the second to use it in a mass-production gasoline-powered vehicle in 2006 with the 911 Turbo (997). Diesel or Diesel fuel (ˈdiːzəl in general is any Fuel used in Diesel engines The most common is a specific fractional distillate of petroleum Porsche SE or Porsche ( German, ˈpɔɹʃə is a German manufacturer of automobiles which is majority-owned by the Porsche and Piëch The Porsche 911 (pronounced as Nine Eleven, Neunelfer is a Sports car made by Porsche AG of Stuttgart, Germany
Parallel operation of the turbochargers can still be used to great effect as demonstrated by the Bugatti Veyron; which runs four relatively small turbochargers in parallel. The Bugatti Veyron 164 is a mid-engine Sports car produced by Volkswagen Group subsidiary Bugatti Automobiles SAS introduced in 2005
Sequential twin-turbo
Sequential twin-turbo refers to a set up in which the motor can utilize only one turbocharger for lower engine speeds, and both turbochargers at higher engine speeds. During low to mid engine speeds, when available spent exhaust energy is minimal, only one turbocharger (the primary turbocharger) is active. During this period, all of the engine's exhaust energy is directed to the primary turbocharger only, lowering the boost threshold, and increasing power output at low engine speeds. Towards the end of this cycle, the secondary turbocharger is partially activated (both compressor and turbine flow) in order to pre-spool the secondary turbocharger prior to its full utilization. Once a preset engine speed or boost pressure is attained, valves controlling compressor and turbine flow through the secondary turbocharger are opened completely. At this point the engine is functioning in a full twin-turbocharger form, providing maximum power output. Sequential twin-turbocharger systems provide a way to decrease turbo lag without compromising ultimate boost output and engine power. A turbocharger, or turbo, is an air Compressor used for forced-induction of an Internal combustion engine. Examples of cars with a sequential twin-turbo setup include the 1993-2002 Toyota Supra Turbo (JZA8x), the 1992-2002 Mazda RX-7 Turbo (FD3S), the 1994-2005 JDM Subaru Legacy RS, and the 1986-1988 Porsche 959. Mark I (1979-1981 1979 In 1978 Toyota began production of the Mark I Supra in Japan, as the Toyota Celica XX. The Mazda RX-7 is a Sports car produced by the Japanese automaker Mazda from 1978 to 2002 The Subaru Legacy is a Mid-size car introduced by the Japanese manufacturer Subaru in February 1989 as a larger companion to the company's The Porsche 959 is a Sports car manufactured by Porsche from 1986 to 1989 first as a Group B rally car and later as a legal Production car designed With recent advancements in turbocharger design, sequential twin turbo systems have fallen out of favor because they are seen as unnecessarily costly and complex.
See also
External links
A boost gauge is a Pressure gauge that indicates manifold air pressure or Turbocharger or Supercharger boost Pressure in an Internal Boost control is the principle of controlling the boost level produced in the Intake manifold of a turbocharged or supercharged engine by affecting A supercharger is an air compressor used for Forced induction of an Internal combustion engine. An intercooler, or Charge air cooler, is an air-to-air or air-to-liquid heat exchange device used on turbocharged and supercharged (forcedDapyx Software network: MP3 Explorer | Ebook Manager | Zenithic