History
Formula 2
As BMW M12/7, the engine design since the 1960s became one of the most successful engines in racing. Starting with the European Touring Car Championship, it was also used in Formula 2, expanded to two-litre and fitted with four-valve heads, producing over . In the Deutsche Rennsport Meisterschaft, a 1400 cc variant (with a 1.4 handicap factor equal to 2000cc) was turbocharged by Paul Rosche according to FIA Group 5 (racing), Group 5 rules. At well over from the beginning, it rendered the normally aspirated engines in the two-litre category useless. After some development, power, driveability, and reliability improved, especially in the International Motor Sports Association, IMSA car, and BMW began to think about entering F1, where a handicap factor of 2.0 required 1500 cc engines.Formula One
During the season, the Brabham team, then owned by future F1 boss Bernie Ecclestone, used both the older Cosworth DFV V8 engine as well as the turbocharged BMW M12 in selected races in a development program. The BMW proved to be fast in its first year in Formula One, though its reliability with turbocharging still in its infancy was lacking. Reigning World Champion Nelson Piquet recorded the first win for the engine in F1 when he led home Brabham teammate Riccardo Patrese (in the Cosworth-powered car) at the 1982 Canadian Grand Prix. In , Brazilian driver Piquet won his second Formula One World Championship driving a Brabham BT52 powered exclusively by the M12, which by that year was producing approximately in qualifying trim and for the races. Piquet, who won the 1983 Brazilian Grand Prix, Brazilian, 1983 Italian Grand Prix, Italian and 1983 European Grand Prix, European Grands Prix that year, won the championship by just two points ahead of Renault F1, Renault's Alain Prost (Renault had pioneered turbocharging in F1 in , but would be destined never to win the World Championship in the original turbo era (1977-1988)). Piquet was the first driver to win a World Championship in a turbo-powered car. The main advantage of the inline-4 M12 over its V6 Ferrari and Renault opposition was that, with one fewer turbo, two fewer cylinders, and eight fewer valves, the BMW engine had lower frictional losses and, therefore, produced less waste heat. This allowed Brahbam's lead designer Gordon Murray the luxury of designing the BT52 with smaller radiators, which meant better aerodynamic efficiency and thus better straight-line speed. The BT52 was notable for its very skinny, short sidepods especially compared to the Renault, giving it better penetration through the air on circuits with long straights. and , by contrast, were lean years for the M12. The engine was generally regarded as the most powerful in F1 at the time, producing approximately in qualifying trim by 1985, and Piquet took nine pole positions in 1984 alone. However, the engine's mechanical reliability and durability under full workload suffered severely, with engine blow-ups and turbo failures becoming common occurrences. Furthermore, with FIA, FISA imposing a maximum fuel limit of 220 litres per race (refuelling was allowed in 1982 and 1983), the 4-cylinder BMW suffered from high fuel consumption which often led to drivers running out of fuel and continued to suffer from poor reliability. Consequently, Piquet scored only three wins - the 1984 1984 Canadian Grand Prix, Canadian and 1984 Detroit Grand Prix, Detroit races, and the 1985 French Grand Prix. These proved to be Brabham's final wins in Formula 1. For , the M12 was upgraded into the M12/13/1. (Bore (engines), Bore 89.2 mm X Stroke (engine), Stroke 60 mm) 374.95 cc and 350 PS per Cylinder (engine), cylinder 933.46 PS/litre This version was claimed to have produced a maximum output of @ 11,000 rpm, and about of torque in qualifying trim, which would make it the most powerful engine ever to race in Formula 1, turbocharged or otherwise. At the time, there was no way to accurately measure horsepower figures over 1,000, and so claimed output figures were generally accepted from the engineers' theoretical calculations; for example, 0.1 bar of turbo boost was rated to be worth approximately ). During the 1986 Italian Grand Prix at Autodromo Nazionale Monza, Monza, Gerhard Berger's BMW-powered Benetton B186 recorded the highest straight line speed by a turbocharged Formula One car when he was timed at . In fact, the top five cars through the speed trap at Monza (Berger and teammate Teo Fabi, Brabham's Derek Warwick and Riccardo Patrese, and the Arrows Grand Prix International, Arrows of Thierry Boutsen) were all powered by the BMW M12. Brabham tilted the upgraded engine sideways by 72° for use in the extremely low Brabham BT55, BT55, but the concept proved unsuccessful, most likely due to cooling issues in the tight compartment. Instead, Benetton Formula, Benetton with the more conventional Benetton B186, B186 were the leading BMW users in 1986, with Gerhard Berger scoring his and the team's first (and the BMW engine's last) win at the 1986 Mexican Grand Prix, Mexican Grand Prix. BMW announced their withdrawal from F1 at the end of 1986, but that they would continue to honour their contract and supply, Brabham, with their tilted M12s for 1987. Arrows team boss Jackie Oliver, with support from the team's primary sponsor USF&G, brokered a deal to continue the use of the upright BMW engines under the name of its subsidiary Megatron, Inc., founded by long-time F1 aficionado John J. Schmidt. The engines were serviced from Switzerland by Arrows' long time engine guru Heini Mader, a former mechanic of Jo Siffert.Megatron
Rebadged as Megatron, the BMW engines were used by the Arrows team for the and seasons, as well as Equipe Ligier, Ligier in 1987. By 1988, Arrows were one of only six teams still running turbocharged engines, and the Megatrons were the oldest turbo engine still in use in Formula One, Scuderia Ferrari, Ferrari having introduced a brand-new turbo engine 1987 Formula One season, the previous year. The Megatron programme ended after 1988 as a result of rule changes that banned turbocharged engines from 1989 onwards, with Eddie Cheever scoring the old BMW engine's last podium finish with third place in the 1988 Italian Grand Prix at Autodromo Nazionale Monza, Monza. This race was also significant as it marked the first time Heini Mader had solved the problems caused by the FIA's boost limit valve, which limited turbo boost pressure to 4.0 bar in 1987 and 2.5 bar in 1988. By moving the valve closer to the engine, the problem of the turbo not delivering enough boost had been solved, and the Arrows A10B was among the fastest cars on the long Monza straights, faster even than the all-conquering McLaren MP4/4, McLaren-Honda F1, Hondas into which designer Steve Nichols had effectively incorporated elements of Gordon Murray's low-line Brabham design as well as featuring a more powerful V6 engine. With turbos banned from the season, the Arrows team reverted to using , Naturally aspirated engine, naturally aspirated Ford DFR V8 power plants. The M12's major shortcoming as a Formula One engine was its lack of throttle response due to turbo lag. Unlike the V6 and V8 turbocharged engines which ran with twin turbos (one for each bank of cylinders), the inline-4 BMW engine, like the other 4 cylinder turbo engines used in F1 such as the Hart (racing), Hart 415T and the Zakspeed, Zakspeed 1500/4, only used a single turbocharger. The twin-turbo setups of the "V" engines eliminated much of the turbo lag. However, with only a single turbo, the BMW M12 suffered from approximately 2 seconds of turbo lag, meaning drivers often had to start accelerating through the apex of a corner. The power from the turbo was described by many (including Piquet and Berger) as coming on like a light switch which often induced sudden oversteer. Consequently, the BMW was usually seen at its most competitive at power circuits such as Kyalami, Autodromo Enzo e Dino Ferrari, Imola, Circuit Paul Ricard, Paul Ricard, Silverstone Circuit, Silverstone, Hockenheimring, Hockenheim, the Österreichring and Monza. On tighter tracks such as street circuits like Circuit de Monaco, Monaco and Detroit street circuit, Detroit which required greater acceleration and less top speed, the BMW-powered cars often lagged behind their major rivals.Formula One record
World Championships: 1 (Nelson Piquet in a Brabham in )Complete Formula One Championship results
(:Template:F1 driver results legend 2, key) (Results in bold indicate pole position; results in ''italics'' indicate fastest lap)References
External links
* http://www.gurneyflap.com/bmwturbof1engine.html * http://grandprix.com/gpe/eng-megat.html * http://www.imca-slotracing.com/2008-XMAS3.htm * http://www.statsf1.com/en/moteur-bmw.aspx {{DEFAULTSORT:Bmw M12 BMW engines, M12 Megatron Formula One engines Straight-four engines