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42-649: N57D30Ox has 1800 bar fuel pressure, while N57D30Tx has 2000 bar fuel pressure. N57D30Ox uses a single turbocharger, while N57D30Tx uses twin-turbochargers , and N57S uses three turbochargers of varying size. Applications: In January 2022, BMW released a statement acknowledging the presence of a technical issue with the N57 engine which contributed to instances of police vehicles in the United Kingdom catching fire, including one case in January 2020 which resulted in

84-512: A Group B rally car and later as a road legal production car designed to satisfy FIA homologation regulations requiring at least 200 units be produced. The twin-turbocharged 959 was the world's fastest street-legal production car when introduced, achieving a top speed of 317 km/h (197 mph), with some variants even capable of achieving 339 km/h (211 mph). Combining race-car performance with luxury-sedan comfort and everyday drivability in dry, wet and snowy conditions, it

126-578: A motor vehicle is responsible for their own crash testing. Porsche chose to design and test the 959 to European safety standards only, ignoring NHTSA standards when it was already apparent that the exchange rate between the Deutschmark and US Dollar was so unfavourable that Porsche was losing $ 200,000 on the sale of each 959. Owners of the few 959s that entered the country paid storage fees to keep their 959s in so-called Foreign Trade Zones (areas adjacent to US ports where goods are not considered to be in

168-509: A new all wheel drive system. Schutz agreed, and gave the project the green light. Bott also knew through experience that a racing program usually helped to accelerate the development of new models. Seeing Group B rallying as the perfect arena to test the new development mule and its all wheel drive system, Bott again went to Schutz and got the approval to develop a car, based on his development mule, for competition in Group B. The powerplant

210-519: A sealed chamber contiguous with the tyre and equipped with a built-in tyre pressure monitoring system. The 959 was actually produced at Karosserie Baur , not at the Porsche factory in Zuffenhausen, on an assembly line with Porsche inspectors overseeing the finished bodies. Most of Porsche's special order interior leather work was also done by the workers at Baur. The 1983 Frankfurt Motor Show

252-416: A single turbo, commonly called a compound twin-turbo system. In this case, multiple similarly sized turbochargers are used in sequence, but constantly operating. The first turbo boosts provides the initial compression (for example to three times the intake pressure). Subsequent turbos take the charge from the previous stage and compress it further (for example to an additional three times intake pressure, for

294-493: A top speed of 198 mph (319 km/h), 0–60 mph (0–97 km/h) in 3.6 seconds, 0–100 mph (0–161 km/h) in 8.2 seconds and 11.9 seconds at 119.5 mph (192.3 km/h) for the quarter mile. Car and Driver measured 0-60 mph in 3.6 seconds in komfort trim which was 9 tenths quicker than any other car they tested in the 1980s. The Porsche 959 S was a 959 "Sport" with larger turbochargers that increased power output to 515 PS (379 kW; 508 hp) thus resulting in

336-559: A top speed of 339 km/h (211 mph) as tested by Auto, Motor und Sport at the Nardò Ring in 1988. To save weight, air conditioning, central locking, electric window lift, rear seats and the levelling system for the chassis were omitted. Twenty-nine cars were built. The 959 was originally meant for Group B racing but development time took longer than expected. The first development race cars, essentially modified 911 Carrera models with all-wheel-drive system known internally as

378-429: A total boost of nine times atmospheric pressure). A downside of staged turbocharging is that it often leads to large amounts of turbo lag, therefore it is mostly used on piston engine aircraft which usually do not need to rapidly raise and lower engine speed. (and thus where turbo lag is not a primary design consideration), and where the intake pressure is quite low due to low atmospheric pressure at altitude, requiring

420-405: A very high pressure ratio. High-performance diesel engines also sometimes use this configuration, since diesel engines do not suffer from pre-ignition issues and can therefore use high boost pressures. http://mkiv.supras.org.nz/articles/twinturbosetups.htm Porsche 959 The Porsche 959 is a sports car manufactured by German automobile manufacturer Porsche from 1986 to 1993, first as

462-438: Is a sequential twin-turbocharged DOHC flat-six engine equipped with 4 valves per cylinder, fuel fed by Bosch Motronic 2.1 fuel injection with air-cooled cylinders and water-cooled heads, with a bore x stroke of 95 mm × 67 mm (3.74 in × 2.64 in) for a total displacement of 2,849 cc (173.9 cu in). It was coupled to a unique manual transmission offering six forward speeds with

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504-507: Is considered significantly important to car culture. Microsoft founder Bill Gates bought a 959 in 1988. Since the model did not have NHTSA and EPA approval, the car was denied entry into the U.S. Fortunately for the car, it was stored for 13 years by the Customs Service , rather than being destroyed, as is customary with forbidden automobiles. On August 13, 1999, the "Show or Display" law came into force, allowing usage of

546-401: Is less kinetic energy present in the exhaust gases) but are unable to provide the quantity of compressed intake gases required at higher RPM. Therefore, sequential turbocharger systems provide a way to decrease turbo lag without compromising power output at high RPM. The system is arranged so that a small ("primary") turbocharger is active while the engine is operating at low RPM, which reduces

588-651: Is that Porsche did not provide the United States Department of Transportation (DOT) with four cars required for destructive crash testing, so the car was never certified by the National Highway Traffic Safety Administration for street use in the U.S. However, this is false as the DOT do not carry out crash testing internally, they simply publish the figures that the manufacturer has released. The manufacturer of

630-488: The 911 starting with the 993 . The twin-turbo system used on the 959 also made its way to future turbocharged Porsche sports cars. In 2004, Sports Car International named the 959 number one on its list of Top Sports Cars of the 1980s. Development of the 959 (originally called the Gruppe B ) started in 1981, shortly after the company's then-new Managing Director, Peter Schutz , took his office. Porsche's chief engineer at

672-549: The 953 , were entered in the 1984 Paris-Dakar Rally , finishing 1st ( René Metge ), 6th ( Jacky Ickx ) and 25th. These cars tested the all-wheel-drive system to be used in the 959. Unlike the World Rally Championship the Dakar didn't require a minimum number of cars built for homologation. In 1985, three cars were entered in the Dakar rally with the proposed 959 body and the rest of the systems but they still used

714-663: The Volvo XC90 and Volkswagen Touareg . Twin-turbo In an internal combustion engine , twin-turbo is a layout in which two turbochargers are used to compress the intake fuel/air mixture (or intake air, in the case of a direct-injection engine ). The most common layout features two identical or mirrored turbochargers in parallel, each processing half of a V engine 's produced exhaust through independent piping. The two turbochargers can either be matching or different sizes. There are three types of turbine setups used for twin-turbo setups: These can be applied to any of

756-488: The 959 to pass emissions requirements , thereby making it street-legal in the United States before falling under the 25 year rule. The upgrade pack has now three generations, as well as a sportier trim available. In Pugad Baboy comic strips, the dog Polgas, in his secret agent persona Agent Pol, has been rewarded with a 959 in lieu of his service and track records in secret service and espionage. A common myth

798-524: The IMSA championship in the United States but suffered tyre issues with Daytona Speedway's banking. The 961 returned to Le Mans in 1987 but while in 11th place Canadian/Dutch driver Kees Nierop mis-shifted from 6th into 2nd gear and crashed into the guard-rail. Upon re-joining the track, the car was observed on TV monitors in the Porsche pits to be on fire and the driver was told to stop and get out of

840-553: The US for legal purposes) as the cars weren't permitted in the US proper. The 959 could not be made street legal in the United States after the 1988 "Imported Vehicle Safety Compliance Act". Otis Chandler, Bill Gates, Bruce Canepa, and others managed to convince the US government to allow the 959 to be imported and thus created the Show or Display law in 1999, where a car is allowed to be imported that did not previously meet federalization, but

882-528: The amount of exhaust piping needed. In this case, each turbocharger is fed exhaust gases by a separate exhaust manifold. For four-cylinder engines and straight-six engines , both turbochargers can be mounted to a single exhaust manifold. The aim of using parallel twin-turbos is to reduce turbo lag by being able to use smaller turbochargers than if a single turbocharger was used for the engine. On engines with multiple cylinder banks (e.g. V engines and flat engines ) use of parallel twin-turbos can also simplify

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924-420: The body panels and chassis construction along with a Nomex floor, instead of the steel floor normally used on their production cars. Porsche also developed the car's aerodynamics , which were designed to increase stability, as was the automatic ride-height adjustment that became available on the road car (961 race cars had a fixed suspension system). Its drag coefficient was as low as 0.31 and aerodynamic lift

966-425: The boost threshold (RPM at which effective boost is provided) and turbo lag. As RPM increases, a small amount of exhaust gas is fed to the larger ("secondary") turbocharger, to bring it up to operating speed. Then at high RPM, all of the exhaust gases are directed to the secondary turbocharger, so that it can provide the boost required by the engine at high RPM. The first production car to use sequential turbocharging

1008-474: The car debuted at a cost of DM431,550 (US$ 225,000) each, still less than half what it cost Porsche to build each car. Production ended in 1988 with 292 cars completed. In total, 337 cars were built, including 37 prototypes and pre-production models. At least one 959 and one 961 remain in the Porsche historic hall in Stuttgart, Germany. In 1992/1993, Porsche built eight more cars assembled from spare parts from

1050-488: The car. Nierop pulled over between marshal stations and this extra time taken to get to the car by the marshals allowed the fire to consume most of the rear end and destroy the car. It was later repaired and put on display at the Porsche Museum . In 2003, Canepa Design initiated a 959 upgrade program. By making modifications to the 959's turbochargers , exhaust system and computer-control systems, Canepa enabled

1092-416: The death of a British police officer . This issue led to police forces across the United Kingdom withdrawing, retiring or limiting the speed of vehicles powered by the N57 engine, preventing their use in pursuits. In the press release, BMW stated “This issue is associated with the particular way in which the police operate these high-performance vehicles […] there is no need for action on civilian vehicles”. It

1134-544: The engine of the 953 rally cars. These cars didn't finish (only one due to mechanical failure however). Afterwards Porsche fitted the cars with twin-turbochargers. Two cars started at the Rallye des Pharaons in October 1985. One of them caught fire, while Saeed Al-Hajri and John Spiller achieved a commanding victory with their 959. At the 1986 Paris-Dakar Rally the 959 finished 1st (René Metge), 2nd (Jacky Ickx) and 6th. By

1176-463: The exhaust system. The 1981–1994 Maserati Biturbo was the first production car to use twin-turbochargers. Sequential turbocharging is a set-up in which the engine uses one turbocharger for lower engine speeds, and a second or both turbochargers at higher engine speeds. This system is intended to overcome the limitation of large turbochargers providing insufficient boost at low RPM. On the other hand, smaller turbos are effective at low RPM (when there

1218-531: The first gear labelled " gelände " (terrain), allowing the car to pass noise regulations, as well as reverse. The engine was largely based on the 4-camshaft 24-valve powerplant used in the Porsche 956 and 962 race cars. These components allowed Porsche to extract 450 PS (331 kW; 444 hp) at 6,500 rpm and 500 N⋅m (369 lb⋅ft) of torque at 5,000 rpm from the compact and efficient power unit. The use of sequential twin turbochargers rather than

1260-493: The five types of compressor setups (which theoretically could have 15 different setups): In a parallel configuration, two equally-sized turbochargers each receive half of the exhaust gases . Some designs combine the intake charge from each turbocharger into a single intake manifold , while others use a separate intake manifold for each turbocharger. Parallel configurations are well suited to V6 and V8 engines since each turbocharger can be assigned to one cylinder bank, reducing

1302-516: The inventory at the manufacturing site in Zuffenhausen . All eight were "Komfort" versions: four in red and four in silver. These cars were much more expensive (DM 747,500) than the earlier ones. The later cars also featured a newly developed speed-sensitive damper system. The cars were sold to selected collectors after being driven by works personnel for some time and are today by far the most sought-after 959 models. If desired, even more power

BMW N57 - Misplaced Pages Continue

1344-442: The more usual identical turbochargers for each of the two cylinder banks allowed for smooth delivery of power across the engine speed band, in contrast to the abrupt on-off power characteristic that distinguished Porsche's other turbocharged engines of the period. The engine was used virtually unchanged in the 959 road car as well. To create a rugged, lightweight shell, Porsche adopted an aluminium and Aramid ( Kevlar ) composite for

1386-406: The rear wheels, helping make the most of the rear-traction bias that occurs at such times. It could also vary the power bias depending on road surface and grip changes, helping maintain traction at all times. The dashboard featured gauges displaying the amount of rear differential slip as well as transmitted power to the front axle. The magnesium alloy wheels were unique, being hollow inside to form

1428-409: The time the 959 was ready for production and homologation in 1987, the Group B programme was cancelled altogether a year prior thus ending Porsche's participation in Group B. In 1986, the racing variant of the 959, the Porsche 961 , made its debut at the 24 Hours of Le Mans . Driven by René Metge partnering Claude Ballot-Léna , it finished first in its class and 7th overall. It also participated in

1470-412: The time, Helmuth Bott, approached Schutz with some ideas about the Porsche 911, or more aptly, a new one. Bott knew that the company needed a sports car that they could continue to rely on for years to come and that could be developed as time went on. Curious as to how much they could do with the rear-engined 911, Bott convinced Schutz that development tests should take place, and even proposed researching

1512-618: Was available to customer cars by Porsche. According to Paul Frère there was an optional 530 PS (390 kW; 523 hp) factory upgrade, with an increased top speed of 336 km/h (209 mph) along with the 0–100 km/h (0–60 mph) acceleration time reduced to 3.4 seconds. Auto, Motor und Sport measured a top speed of 317 km/h (197 mph) and 3.7 seconds for 0–100 km/h (0–62 mph). Those values were recognized by Guinness World Records as highest road tested speed for any road car and highest road tested 0-100 km/h acceleration. Road & Track measured

1554-482: Was chosen for the unveiling of the Porsche Group B prototype. Even in the closing hours of October 9, finishing touches were being applied to the car to go on display the next morning. After the first two prototypes, the bodywork was modified to include air vents in the front and rear wheel housings, as well as intake holes behind the doors. The first prototype receiving those modifications was code named "F3", and

1596-513: Was considered the most technologically advanced road car of its time. After the successful introduction of all-wheel drive on more rally-specific cars like the Audi Quattro , it was one of the first pure high-performance sports-cars with all-wheel drive , providing the basis for Porsche's first all-wheel drive 911 Carrera 4 model. Its performance convinced Porsche executives to make all-wheel drive standard on all turbocharged versions of

1638-416: Was destroyed in the first crash test. The road version of the 959 debuted at the 1985 Frankfurt Motor Show as a 1986 model, but numerous issues delayed production by more than a year. The car was manufactured in two levels of trim, "Komfort" and "Sport", corresponding to the trim with more creature comforts and a more track focused trim. First customer deliveries of the 959 street variant began in 1987, and

1680-456: Was eliminated. The 959 also featured Porsche-Steuer Kupplung (PSK) all-wheel-drive system. Capable of dynamically changing the torque distribution between the rear and front wheels in both normal and slip conditions, the PSK system gave the 959 the adaptability it needed both as a race car and as a "super" street car. Under hard acceleration, PSK could send as much as 80% of the available power to

1722-547: Was reported that the issue was caused by high-speed driving after long periods of engine idling. Safety concerns about this engine in 2016, and the 2022 inquest into the death of PC Nicholas Dumphreys on 26 January 2020, had the consequence that in January 2023, BMW stopped supplying cars to UK police altogether and closed down their International and Specialist Sales Division at their dealership in Park Lane, Mayfair. Police forces are instead moving to other brands, such as

BMW N57 - Misplaced Pages Continue

1764-427: Was the 1986–1988 Porsche 959 , which used sequential twin-turbos on its flat-six engine. Serial turbocharging is where the turbochargers are connected in series with the output of the first turbocharger then being further compressed by the second turbocharger and in some cases powering the larger turbine. A serial turbo can also be of use to a system where the output pressure must be greater than can be provided by

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