{{unreferenced, date=September 2008 GM-1 (''Göring Mischung'' 1) was a system for injecting

nitrous oxide Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or nos, is a chemical compound, an oxide of nitrogen with the formula . At room temperature, it is a colourless non-flammable gas, and has a ...

(laughing gas) into

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years many ...

s that was used by the ''

Luftwaffe The ''Luftwaffe'' () was the aerial-warfare branch of the German ''Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the ''Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabtei ...

'' in

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. This increased the amount of

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

in the fuel mixture, and thereby improved high-altitude performance. GM-1 was used on a number of modifications of existing fighter designs in order to counter the increasing performance of Allied fighters at higher altitudes. A different system for low-altitude boost known as

MW 50 MW 50 (Methanol-''Wasser'' 50) was a 50-50 mixture of methanol and water (German: ''Wasser'') that was often sprayed into the supercharger of World War II aircraft engines primarily for its anti-detonation effect, allowing the use of increased bo ...

was also used, although GM-1 and MW 50 were rarely used on the same engine. MW-50 was a ''

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a ...

''-''

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

'' injection system, which injected a mixture of methanol and water into the cylinders to cool the mix. Cooling causes the air to become denser, therefore allowing more air into each cylinder for a given volume. This is the same principle that intercoolers use. GM-1 was developed in 1940 by

Otto Lutz Otto is a masculine German given name and a surname. It originates as an Old High German short form (variants ''Audo'', '' Odo'', ''Udo'') of Germanic names beginning in ''aud-'', an element meaning "wealth, prosperity". The name is recorded f ...

to improve high-altitude performance. It could be used by fighters,

destroyer In naval terminology, a destroyer is a fast, manoeuvrable, long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against powerful short range attackers. They were originally developed in ...

s, bombers and reconnaissance aircraft, though its first use was in the

Bf 109 The Messerschmitt Bf 109 is a German World War II fighter aircraft that was, along with the Focke-Wulf Fw 190, the backbone of the Luftwaffe's fighter force. The Bf 109 first saw operational service in 1937 during the Spanish Civil War an ...

E/Z fighter. Originally, it was liquified under high pressure and stored in several high-pressure vessels until it was found that low-temperature liquefied nitrous oxide gave better performance due to improved charge cooling. It could also be stored and handled more conveniently and was less vulnerable to enemy fire. GM-1 was typically sprayed in liquid form directly into the supercharger intake from two jets of different bore while at the same time, the fuel flow was increased to take advantage of the additional oxygen from the nitrous oxide. The jets could be operated individually or in combination, yielding three steps of power increase, for example 120/240/360 HP at different GM-1 flow rates (60, 100 and 150 grams/sec). The development of a continuously variable injection system was considered, but apparently it never saw operational use. Initially intended as standard equipment for the ''Luftwaffe'', in operational service it was found that GM-1 had some drawbacks. The additional weight of the equipment reduced performance on all missions, while the system was only used in the cases where the aircraft went to very high altitudes. GM-1 also became less attractive than originally imagined when in 1943, the previous trend towards ever increasing combat altitudes ended. While GM-1 saw little use in the second half of the war, the Focke-Wulf Ta 152H, which had been developed as a dedicated high-altitude interceptor, also received a GM-1 system to provide it with superior performance at high altitude. The Ta 152H was one of the few designs to support both GM-1 and MW 50. Similar systems have been used in

racing car Auto racing (also known as car racing, motor racing, or automobile racing) is a motorsport involving the racing of automobiles for competition. Auto racing has existed since the invention of the automobile. Races of various sorts were organise ...

s and

hot rod Hot rods are typically American cars that might be old, classic, or modern and that have been rebuilt or modified with large engines optimised for speed and acceleration. One definition is: "a car that's been stripped down, souped up and made ...

External links

Messerschmitt Bf 109 Site - Short Operating Manual for pilots and ground personnel for the GM-1 system in the Bf 109 G (In German).
Aircraft engines

See also

External links