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| {{Short description|Automotive supplement}} | |||
| ⚫ | |||
| ⚫ | {{about|the use of nitrous oxide in a motorsports context|other uses|Nitrous oxide}} | ||
| ] | |||
| {{redirect|Nitrous|the chemical terminology and other uses|nitrogen compounds}} | |||
| {{Refimprove|date=April 2009 }} | |||
| ] | |||
| '''Nitrous''' is a slang term for ] (N<sub>2</sub>O), commonly used by drag racing classes like Pro Street, Top Sportsman, and Pro Mod. Nitrous oxide is an ] used to increase an engine's power output by allowing for faster burning of a fuel (usually ]). Nitrous can be used with ] in the mud racing categories. | |||
| A '''nitrous oxide engine,''' or '''nitrous oxide system''' ('''NOS''') is an ] in which oxygen for burning the fuel comes from the decomposition of ], N<sub>2</sub>O, as well as air. The system increases the engine's power output by allowing fuel to be burned at a higher-than-normal rate, because of the higher ] of oxygen injected with the ].<ref>{{cite web|url=http://www.automoblog.net/2011/09/27/nitrous-everything-you-need-to-know/|title=Nitrous: Everything You Need to Know|publisher=Automoblog.net |date=2011-09-27 |access-date=2013-07-11}}</ref> Nitrous injection systems may be "dry", where the nitrous oxide is injected separately from fuel, or "wet" in which additional fuel is carried into the engine along with the nitrous. NOS may not be permitted for street or highway use, depending on local regulations. N<sub>2</sub>O use is permitted in certain classes of auto racing. Reliable operation of an engine with nitrous injection requires careful attention to the strength of engine components and to the accuracy of the mixing systems, otherwise destructive detonations or exceeding engineered component maximums may occur. Nitrous oxide systems were applied as early as World War II for certain aircraft engines. | |||
| ==Overview== | |||
| Nitrous oxide boosts engine performance in a number of ways, some of which are not fully understood. Its primary effect seems to be exerted through its ability to release oxygen at high temperatures. When nitrous oxide decomposes, a single mole will release 1/2 mole of oxygen, allowing an oxygen saturation of 33% to be reached. Air, which contains only 21% oxygen, permits a maximum saturation of only 21%. This oxygen combines with hydrocarbons such as gasoline, alcohol, and diesel fuel to produce carbon dioxide and water vapor, which expand and exert pressure on pistons. The greater the oxygen saturation, the higher the pressure and the greater the power released. However, peak cylinder pressure alone does not determine engine performance. | |||
| ==Terminology== | |||
| Nitrous oxide is stored as a liquid in tanks, but because of its low boiling point it will vaporize when it enters a cylinder during the intake stroke. As it boils, the cylinder temperature will drop, reducing the pressure during the compression stroke and thus reducing power loss. This drop in intake manifold temperature also increases the density of the air/fuel charge, thereby increasing the cylinders volumetric efficiency. | |||
| In the context of racing, nitrous oxide is often termed '''nitrous''' or '''NOS'''. The term NOS is derived from the initials of the company name '''Nitrous Oxide Systems, Inc.''' (now a brand of ]) one of the pioneering companies in the development of nitrous oxide injection systems for automotive performance use, and has become a ]. '''Nitro''' is also sometimes used, though incorrect, as it refers more to ]. | |||
| ==Mechanism== | |||
| There is a third way in which nitrous improves engine performance. When N<sub>2</sub>O breaks down to release oxygen, nitrogen (N<sub>2</sub>) is also formed. Nitrogen gas contains molecules with extremely stable triple bonds, and so the formation of nitrogen is very exothermic. Because N<sub>2</sub> is generated during the engine's power stroke, nitrous boosts power by increasing the temperature inside the cylinder by the formation of diatomic nitrogen. | |||
| When a ] of nitrous oxide decomposes, it releases half a mole of O<sub>2</sub> molecules (oxygen gas), and one mole of N<sub>2</sub> molecules (nitrogen gas). This decomposition allows an oxygen concentration of 36.36% to be reached. Nitrogen gas is non-combustible and does not support combustion. ]—which contains only 21% oxygen, the rest being nitrogen and other equally non-combustible and non-combustion-supporting gasses—permits a 12-percent-lower maximum-oxygen level than that of nitrous oxide. This oxygen supports combustion; it combines with fuels such as gasoline, alcohol, ], ], or ] (CNG) to produce ] and water vapor, along with heat, which causes the former two products of combustion to expand and exert pressure on pistons, driving the engine. | |||
| Nitrous oxide is stored as a liquid in tanks, but is a gas under atmospheric conditions. When injected as a liquid into an inlet manifold, the vaporization and expansion causes a reduction in air/fuel charge temperature with an associated increase in density, thereby increasing the cylinder's ]. | |||
| The original company in nitrous oxide injection was NOS. Today, there are several competing companies in the field, including BOSS NOSS, NOS, ZEX, Compucar, Top Gun, Nitrous Pro Flow, Nitrous Express, Nitrous Works, Cold Fusion, and ]. | |||
| As the decomposition of N<sub>2</sub>O into oxygen and nitrogen gas is ] and thus contributes to a higher temperature in the combustion engine, the decomposition increases engine efficiency and performance, which is directly related to the difference in temperature between the unburned fuel mixture and the hot combustion gasses produced in the cylinders. | |||
| Nitrous systems can increase power by 45% or more, depending on configuration, and are usually built in one or two stages. All Pro Mod cars and some Pro Steet cars use three stages, for additional power. | |||
| All systems are based on a single stage kit, but these kits can be used in multiples (called two-, three-, or even four-stage kits). The most advanced systems are controlled by an electronic progressive delivery unit that allows a single kit to perform better than multiple kits can. Most Pro Mod and some Pro Street drag race cars use three stages for additional power, but more and more are switching to pulsed progressive technology. Progressive systems have the advantage of utilizing a larger amount of nitrous (and fuel) to produce even greater power increases as the additional power and torque are gradually introduced (as opposed to being applied to the engine and transmission immediately), reducing the risk of mechanical shock and, consequently, damage. | |||
| ⚫ | |||
| ==Identification== | |||
| ⚫ | Cars with nitrous-equipped engines may be identified by the "purge" of the delivery system that most drivers perform prior to reaching the starting line. A separate electrically operated valve is used to release air and gaseous nitrous oxide trapped in the delivery system. This brings liquid nitrous oxide all the way up through the plumbing from the storage tank to the ] valve or valves that will release it into the engine's intake tract. When the purge system is activated, one or more plumes of nitrous oxide will be visible for a moment as the liquid flashes to vapor as it is released. The purpose of a nitrous purge is to ensure that the correct amount of nitrous oxide is delivered the moment the system is activated as nitrous and fuel jets are sized to produce correct air / fuel ratios, and as liquid nitrous is denser than gaseous nitrous, any nitrous vapor in the lines will cause the car to "bog" for an instant (as the ratio of nitrous / fuel will be too rich reducing engine power) until liquid nitrous oxide reaches the injection nozzle. | ||
| ==Types of nitrous systems== | ==Types of nitrous systems== | ||
| There are |
There are two categories of nitrous systems: ''dry'' & ''wet'' with four main delivery methods of nitrous systems: ''single nozzle'', ''direct port'', ''plate'', and ''bar'' used to discharge nitrous into the ]s of the ]. Nearly all nitrous systems use specific orifice inserts, called jets, along with pressure calculations to meter the nitrous, or nitrous and fuel in wet applications, delivered to create a proper ] (AFR) for the additional horsepower desired. | ||
| === |
===Dry=== | ||
| In a |
In a ''dry'' nitrous system the nitrous delivery method provides nitrous only. The extra fuel required is introduced through the ], keeping the manifold dry of fuel. This property is what gives the dry system its name. Fuel flow can be increased either by increasing the pressure or by increasing the time the fuel injectors remain open. | ||
| Dry nitrous systems typically rely on a single nozzle delivery method, but all of the four main delivery methods can be used in dry applications. Dry systems are not typically used in carbureted applications due to the nature of a carburetor's function and inability to provide large amounts of on-demand fuel. Dry nitrous systems on fuel injected engines will use increased fuel pressure or injector pulsewidth upon system activation as a means of providing the correct ratio of fuel for the nitrous. | |||
| ==="Wet single-point" nitrous system=== | |||
| A "wet single-point" nitrous system introduces the fuel and nitrous together, causing the upper intake to become wet with fuel. In carbureted applications, this is typically accomplished with a spraybar plate mounted between the carburetor base and the intake manifold, while cars fitted with electronic fuel injection often use a plate mounted between the manifold and the base of the throttle body, or a single nozzle mounted in the intake tract. However, the intake must be designed for wet flow (for example, carburetors also require a wet flow intake), as distribution problems or intake backfires may result. Dry-flow intakes are designed to contain only air, which will travel through smaller pipes and tighter turns with less pressure, whereas wet-flow intakes are designed to contain a mixture of fuel and air. "Wet" nitrous systems tend to produce more power than "dry" systems, but are correspondingly more expensive and difficult to install. | |||
| === |
===Wet=== | ||
| In a ''wet'' nitrous system the nitrous delivery method provides nitrous and fuel together resulting in the intake manifold being "wet" with fuel, giving the category its name. Wet nitrous systems can be used in all four main delivery methods. | |||
| A "wet direct port" nitrous system introduces nitrous and fuel directly into each intake port on the engine. These systems are also known as direct port nitrous systems. Normally, these systems combine nitrous and fuel through several nozzles similar in design to a "wet single-point" nozzle, which mixes and meters the nitrous and fuel delivered to each cylinder individually, allowing each cylinder's nitrous/fuel ratio to be adjusted without affecting the other cylinders. Note that there are still several ways to introduce nitrous via a direct port system. There are several different types of nozzles and placements ranging from fogger nozzles that require you to drill and tap your manifold, to specialty direct port efi nozzles that fit into your fuel injector ports along with your fuel injectors. | |||
| In wet systems on fuel/direct injected engines care must be taken to avoid backfires caused by fuel pooling in the intake tract or manifold and/or uneven distribution of the nitrous/fuel mixture. Port and direct fuel injection engines have intake systems engineered for the delivery of air only, not air and fuel. Since most fuels are heavier than air and not in a gaseous state when used with nitrous systems it does not behave in the same way as air alone; thus the possibility of the fuel being unevenly distributed to the combustion chambers of the engine causing lean conditions/detonation and/or pooling in parts of the intake tract/manifold presenting a dangerous situation in which the fuel may be ignited uncontrollably causing catastrophic failure to components. Carbureted and single point/throttle body injected engines use a wet manifold design that is engineered to evenly distribute fuel and air mixtures to all combustion chambers, making this mostly a non-issue for these applications. | |||
| A multi-point system is the most powerful and efficient type of nitrous system, due to the placement of the nozzle in each runner, as well as the ability to use more and higher capacity ] valves. Wet multi-point kits can go as high as 1,100 ] (820 kW) with only one stage, but most produce that much power with two or three systems. These systems are also the most complex and expensive systems, requiring significant modification to the engine, including adding a distribution block and solenoid assembly, as well as drilling, tapping, and building plumbing for each cylinder intake. These systems are most often used on racing vehicles specially built to take the strain of such high power levels. Many high-horsepower race applications will use more than one nozzle per cylinder, plumbed in "stages" to allow greater control of how much power is delivered with each stage. A two-stage system will actually allow three different levels of additional horsepower; for example, a small first stage can be used in first gear to prevent excessive wheelspin, then turned off in favor of a larger second stage once the car is moving. In top gear, both stages can be activated at the same time for maximum horsepower. | |||
| === |
===Single nozzle=== | ||
| A ''single nozzle'' nitrous system introduces the nitrous or fuel/nitrous mixture via a single injection point. The nozzle is typically placed in the intake pipe/tract after the air filter, prior to the intake manifold and/or throttle body in fuel injected applications, and after the throttle body in carbureted applications. In wet systems the high pressures of the nitrous injected causes the ] of the fuel injected in tandem via the nozzle, allowing for more thorough and even distribution of the nitrous/fuel mixture. | |||
| ===Direct port=== | |||
| Another type of system is called a plenum bar system. These are spraybars that are installed inside of the plenums of the intake manifold. Plenum bar systems are usually used in conjunction with direct port systems in multi-stage nitrous systems. | |||
| A ''direct port'' nitrous system introduces the nitrous or fuel/nitrous mixture as close to the intake ports of the engine as is feasible via individual nozzles directly in each intake runner. Direct port nitrous systems will use the same or similar nozzles as those in single nozzle systems, just in numbers equal to or in multiples of the number of intake ports of the engine. Being that direct port systems do not have to rely on intake tract/manifold design to evenly distribute the nitrous or fuel/nitrous mixture, they are inherently more precise than other delivery methods. The greater number of nozzles also allows a greater total amount of nitrous to be delivered than other systems. Multiple "stages" of nitrous can be accomplished by using multiple sets of nozzles at each intake port to further increase the power potential. Direct port nitrous systems are the most common delivery method in racing applications. | |||
| == |
===Plate=== | ||
| A ''plate'' nitrous system uses a spacer placed somewhere between the throttle body and intake ports with holes drilled along its interior surfaces, or in a tube that is suspended from the plate, for the nitrous or fuel/nitrous mixture to be distributed through. Plate systems provide a drill-less solution compared to other delivery methods as the plates are generally application specific and fit between existing components such as the throttle body-to-intake-manifold or upper-intake-manifold-to-lower-intake-manifold junctions. Requiring little more than longer fasteners, plate systems are the most easily reversed systems as they need little to no permanent changes to the intake tract. Dependent on application, plate systems can provide precise nitrous or fuel/nitrous mixture distribution similar to that of direct port systems. | |||
| The same technique was used during ] by Luftwaffe aircraft with the ] system to boost the power output of ]s. Originally meant to provide the Luftwaffe standard aircraft with superior high-altitude performance, technological considerations limited its use to extremely high altitudes. Accordingly, it was only used by specialized planes like high-altitude reconnaissance aircraft, high-speed bombers and high-altitude interceptors. | |||
| ===Bar=== | |||
| ⚫ | British World War II usage of nitrous oxide injector systems were modifications of Merlin engines carried out by the Heston Aircraft Company for use in certain night fighter variants of the de Havilland Mosquito and |
||
| A ''bar'' nitrous system utilizes a hollow tube, with a number of holes drilled along its length, placed inside the intake plenum to deliver nitrous. Bar nitrous delivery methods are almost exclusively dry nitrous systems due to the non-optimal fuel distribution possibilities of the bar. Bar nitrous systems are popular with racers that prefer their nitrous use to be hidden, as the nitrous distribution method is not immediately apparent and most associated components of the nitrous system can be obscured from view. | |||
| === |
===Propane or CNG=== | ||
| Nitrous systems can be used with a gaseous fuel such as propane or compressed natural gas. This has the advantage of being technically a ''dry'' system as the fuel is not in a liquid state when introduced to the intake tract. | |||
| *A fairly complete Nitrous FAQ related to use in vehicles | |||
| *Another page of original Nitrous related use of NOS nitrous info | |||
| ==Reliability concerns== | |||
| ⚫ | ==External links |
||
| ] | |||
| The use of nitrous oxide carries with it concerns about the reliability and longevity of an engine present with all power adders. Due to the greatly increased cylinder pressures, the engine as a whole is placed under greater stress, primarily those components associated with the engine's rotating assembly. An engine with components unable to cope with the increased stress imposed by the use of nitrous systems can experience major engine damage, such as cracked or destroyed pistons, connecting rods, crankshafts, and/or blocks. Proper strengthening of engine components in addition to accurate and adequate fuel delivery are key to nitrous system use without catastrophic failure. | |||
| * | |||
| * | |||
| * | |||
| * | |||
| * | |||
| * | |||
| In addition, nitrous oxide should not be used in vehicles with an ], as the highly increased engine power and torque may cause stress damage to the ] and the transmission itself. | |||
| ⚫ | ] | ||
| ⚫ | ] | ||
| ==Street legality== | |||
| ] | |||
| Nitrous oxide injection systems for automobiles are illegal for road use in some countries. For example, in ], Australia, the ] '''Code of Practice for Light Vehicle Modifications''' (in use since 1994) states in clause 3.1.5.7.3 that ''The use or fitment of nitrous oxide injection systems is not permitted.''<ref>{{cite book | |||
| ] | |||
| | title = Code of Practice for Light Vehicle Modifications | |||
| | publisher = ] | |||
| | year = 1994 | |||
| | isbn = 0-7310-2923-2 }}</ref> | |||
| In Great Britain, there are no restrictions on use of {{chem|N|2|O}}, but the modification must be declared to the insurance company, which is likely to result in a higher premium for Motor Vehicle insurance or refusal to insure. | |||
| In Germany, despite its strict ] rules, a nitrous system can be installed and used legally in a street driven car. The requirements for the technical standard of the system are similar to those of aftermarket ]. | |||
| ==Racing rules== | |||
| Several sanctioning bodies in drag racing allow or disallow the use of nitrous oxide in certain classes or have nitrous oxide specific classes. Nitrous is allowed in ] competition. | |||
| ==History== | |||
| A similar basic technique was used during ] by ] aircraft with the ] system to maintain the power output of ]s when at high altitude where the air density is lower. Accordingly, it was only used by specialized planes like high-altitude reconnaissance aircraft, high-speed bombers and high-altitude interceptors. It was sometimes used with the Luftwaffe's form of ], designated ] (both meant as ''Notleistung'' short-term power boosting measures), to produce substantial increases in performance for fighter aircraft ], as with their combined use on the ]H fighter prototypes.<ref>{{cite book |last=Hermann |first=Dietmar |date=1998 |title=Focke-Wulf Ta 152: Der Weg zum Höhenjäger (in German) |location=Oberhaching, Germany |publisher=AVIATIC Verlag GmbH |pages=12, 141 |isbn=3-925505-44-X }}</ref> | |||
| ⚫ | British World War II usage of nitrous oxide injector systems were modifications of ] carried out by the Heston Aircraft Company for use in certain night fighter variants of the ] and photo reconnaissance versions of the ]. | ||
| ==See also== | |||
| * ] | |||
| * ] | |||
| * Water injection | |||
| * ] | |||
| * ], is ] are used ] or ] for more accelerations (as alternative of '''Nitrous Oxide Engine''') | |||
| ==References== | |||
| {{Reflist}} | |||
| ⚫ | ==External links== | ||
| * | |||
| ⚫ | ] | ||
| ⚫ | ] | ||
| ] | |||
Latest revision as of 14:46, 1 October 2024
Automotive supplement This article is about the use of nitrous oxide in a motorsports context. For other uses, see Nitrous oxide. "Nitrous" redirects here. For the chemical terminology and other uses, see nitrogen compounds. | This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Nitrous oxide engine" – news · newspapers · books · scholar · JSTOR (April 2009) (Learn how and when to remove this message) |
A nitrous oxide engine, or nitrous oxide system (NOS) is an internal combustion engine in which oxygen for burning the fuel comes from the decomposition of nitrous oxide, N2O, as well as air. The system increases the engine's power output by allowing fuel to be burned at a higher-than-normal rate, because of the higher partial pressure of oxygen injected with the fuel mixture. Nitrous injection systems may be "dry", where the nitrous oxide is injected separately from fuel, or "wet" in which additional fuel is carried into the engine along with the nitrous. NOS may not be permitted for street or highway use, depending on local regulations. N2O use is permitted in certain classes of auto racing. Reliable operation of an engine with nitrous injection requires careful attention to the strength of engine components and to the accuracy of the mixing systems, otherwise destructive detonations or exceeding engineered component maximums may occur. Nitrous oxide systems were applied as early as World War II for certain aircraft engines.
Terminology
In the context of racing, nitrous oxide is often termed nitrous or NOS. The term NOS is derived from the initials of the company name Nitrous Oxide Systems, Inc. (now a brand of Holley Performance Products) one of the pioneering companies in the development of nitrous oxide injection systems for automotive performance use, and has become a genericized trademark. Nitro is also sometimes used, though incorrect, as it refers more to nitromethane engines.
Mechanism
When a mole of nitrous oxide decomposes, it releases half a mole of O2 molecules (oxygen gas), and one mole of N2 molecules (nitrogen gas). This decomposition allows an oxygen concentration of 36.36% to be reached. Nitrogen gas is non-combustible and does not support combustion. Air—which contains only 21% oxygen, the rest being nitrogen and other equally non-combustible and non-combustion-supporting gasses—permits a 12-percent-lower maximum-oxygen level than that of nitrous oxide. This oxygen supports combustion; it combines with fuels such as gasoline, alcohol, diesel fuel, propane, or compressed natural gas (CNG) to produce carbon dioxide and water vapor, along with heat, which causes the former two products of combustion to expand and exert pressure on pistons, driving the engine.
Nitrous oxide is stored as a liquid in tanks, but is a gas under atmospheric conditions. When injected as a liquid into an inlet manifold, the vaporization and expansion causes a reduction in air/fuel charge temperature with an associated increase in density, thereby increasing the cylinder's volumetric efficiency.
As the decomposition of N2O into oxygen and nitrogen gas is exothermic and thus contributes to a higher temperature in the combustion engine, the decomposition increases engine efficiency and performance, which is directly related to the difference in temperature between the unburned fuel mixture and the hot combustion gasses produced in the cylinders.
All systems are based on a single stage kit, but these kits can be used in multiples (called two-, three-, or even four-stage kits). The most advanced systems are controlled by an electronic progressive delivery unit that allows a single kit to perform better than multiple kits can. Most Pro Mod and some Pro Street drag race cars use three stages for additional power, but more and more are switching to pulsed progressive technology. Progressive systems have the advantage of utilizing a larger amount of nitrous (and fuel) to produce even greater power increases as the additional power and torque are gradually introduced (as opposed to being applied to the engine and transmission immediately), reducing the risk of mechanical shock and, consequently, damage.
Identification
Cars with nitrous-equipped engines may be identified by the "purge" of the delivery system that most drivers perform prior to reaching the starting line. A separate electrically operated valve is used to release air and gaseous nitrous oxide trapped in the delivery system. This brings liquid nitrous oxide all the way up through the plumbing from the storage tank to the solenoid valve or valves that will release it into the engine's intake tract. When the purge system is activated, one or more plumes of nitrous oxide will be visible for a moment as the liquid flashes to vapor as it is released. The purpose of a nitrous purge is to ensure that the correct amount of nitrous oxide is delivered the moment the system is activated as nitrous and fuel jets are sized to produce correct air / fuel ratios, and as liquid nitrous is denser than gaseous nitrous, any nitrous vapor in the lines will cause the car to "bog" for an instant (as the ratio of nitrous / fuel will be too rich reducing engine power) until liquid nitrous oxide reaches the injection nozzle.
Types of nitrous systems
There are two categories of nitrous systems: dry & wet with four main delivery methods of nitrous systems: single nozzle, direct port, plate, and bar used to discharge nitrous into the plenums of the intake manifold. Nearly all nitrous systems use specific orifice inserts, called jets, along with pressure calculations to meter the nitrous, or nitrous and fuel in wet applications, delivered to create a proper air-fuel ratio (AFR) for the additional horsepower desired.
Dry
In a dry nitrous system the nitrous delivery method provides nitrous only. The extra fuel required is introduced through the fuel injectors, keeping the manifold dry of fuel. This property is what gives the dry system its name. Fuel flow can be increased either by increasing the pressure or by increasing the time the fuel injectors remain open.
Dry nitrous systems typically rely on a single nozzle delivery method, but all of the four main delivery methods can be used in dry applications. Dry systems are not typically used in carbureted applications due to the nature of a carburetor's function and inability to provide large amounts of on-demand fuel. Dry nitrous systems on fuel injected engines will use increased fuel pressure or injector pulsewidth upon system activation as a means of providing the correct ratio of fuel for the nitrous.
Wet
In a wet nitrous system the nitrous delivery method provides nitrous and fuel together resulting in the intake manifold being "wet" with fuel, giving the category its name. Wet nitrous systems can be used in all four main delivery methods.
In wet systems on fuel/direct injected engines care must be taken to avoid backfires caused by fuel pooling in the intake tract or manifold and/or uneven distribution of the nitrous/fuel mixture. Port and direct fuel injection engines have intake systems engineered for the delivery of air only, not air and fuel. Since most fuels are heavier than air and not in a gaseous state when used with nitrous systems it does not behave in the same way as air alone; thus the possibility of the fuel being unevenly distributed to the combustion chambers of the engine causing lean conditions/detonation and/or pooling in parts of the intake tract/manifold presenting a dangerous situation in which the fuel may be ignited uncontrollably causing catastrophic failure to components. Carbureted and single point/throttle body injected engines use a wet manifold design that is engineered to evenly distribute fuel and air mixtures to all combustion chambers, making this mostly a non-issue for these applications.
Single nozzle
A single nozzle nitrous system introduces the nitrous or fuel/nitrous mixture via a single injection point. The nozzle is typically placed in the intake pipe/tract after the air filter, prior to the intake manifold and/or throttle body in fuel injected applications, and after the throttle body in carbureted applications. In wet systems the high pressures of the nitrous injected causes the aerosolization of the fuel injected in tandem via the nozzle, allowing for more thorough and even distribution of the nitrous/fuel mixture.
Direct port
A direct port nitrous system introduces the nitrous or fuel/nitrous mixture as close to the intake ports of the engine as is feasible via individual nozzles directly in each intake runner. Direct port nitrous systems will use the same or similar nozzles as those in single nozzle systems, just in numbers equal to or in multiples of the number of intake ports of the engine. Being that direct port systems do not have to rely on intake tract/manifold design to evenly distribute the nitrous or fuel/nitrous mixture, they are inherently more precise than other delivery methods. The greater number of nozzles also allows a greater total amount of nitrous to be delivered than other systems. Multiple "stages" of nitrous can be accomplished by using multiple sets of nozzles at each intake port to further increase the power potential. Direct port nitrous systems are the most common delivery method in racing applications.
Plate
A plate nitrous system uses a spacer placed somewhere between the throttle body and intake ports with holes drilled along its interior surfaces, or in a tube that is suspended from the plate, for the nitrous or fuel/nitrous mixture to be distributed through. Plate systems provide a drill-less solution compared to other delivery methods as the plates are generally application specific and fit between existing components such as the throttle body-to-intake-manifold or upper-intake-manifold-to-lower-intake-manifold junctions. Requiring little more than longer fasteners, plate systems are the most easily reversed systems as they need little to no permanent changes to the intake tract. Dependent on application, plate systems can provide precise nitrous or fuel/nitrous mixture distribution similar to that of direct port systems.
Bar
A bar nitrous system utilizes a hollow tube, with a number of holes drilled along its length, placed inside the intake plenum to deliver nitrous. Bar nitrous delivery methods are almost exclusively dry nitrous systems due to the non-optimal fuel distribution possibilities of the bar. Bar nitrous systems are popular with racers that prefer their nitrous use to be hidden, as the nitrous distribution method is not immediately apparent and most associated components of the nitrous system can be obscured from view.
Propane or CNG
Nitrous systems can be used with a gaseous fuel such as propane or compressed natural gas. This has the advantage of being technically a dry system as the fuel is not in a liquid state when introduced to the intake tract.
Reliability concerns
The use of nitrous oxide carries with it concerns about the reliability and longevity of an engine present with all power adders. Due to the greatly increased cylinder pressures, the engine as a whole is placed under greater stress, primarily those components associated with the engine's rotating assembly. An engine with components unable to cope with the increased stress imposed by the use of nitrous systems can experience major engine damage, such as cracked or destroyed pistons, connecting rods, crankshafts, and/or blocks. Proper strengthening of engine components in addition to accurate and adequate fuel delivery are key to nitrous system use without catastrophic failure.
In addition, nitrous oxide should not be used in vehicles with an automatic transmission, as the highly increased engine power and torque may cause stress damage to the torque converter and the transmission itself.
Street legality
Nitrous oxide injection systems for automobiles are illegal for road use in some countries. For example, in New South Wales, Australia, the Roads & Traffic Authority Code of Practice for Light Vehicle Modifications (in use since 1994) states in clause 3.1.5.7.3 that The use or fitment of nitrous oxide injection systems is not permitted.
In Great Britain, there are no restrictions on use of N
2O, but the modification must be declared to the insurance company, which is likely to result in a higher premium for Motor Vehicle insurance or refusal to insure.
In Germany, despite its strict TÜV rules, a nitrous system can be installed and used legally in a street driven car. The requirements for the technical standard of the system are similar to those of aftermarket natural gas conversions.
Racing rules
Several sanctioning bodies in drag racing allow or disallow the use of nitrous oxide in certain classes or have nitrous oxide specific classes. Nitrous is allowed in Formula Drift competition.
History
A similar basic technique was used during World War II by Luftwaffe aircraft with the GM-1 system to maintain the power output of aircraft engines when at high altitude where the air density is lower. Accordingly, it was only used by specialized planes like high-altitude reconnaissance aircraft, high-speed bombers and high-altitude interceptors. It was sometimes used with the Luftwaffe's form of methanol-water injection, designated MW 50 (both meant as Notleistung short-term power boosting measures), to produce substantial increases in performance for fighter aircraft over short periods of time, as with their combined use on the Focke-Wulf Ta 152H fighter prototypes.
British World War II usage of nitrous oxide injector systems were modifications of Merlin engines carried out by the Heston Aircraft Company for use in certain night fighter variants of the de Havilland Mosquito and photo reconnaissance versions of the Supermarine Spitfire.
See also
- Car tuning
- Turbocharger
- Water injection
- Racing games
- Halogen engine, is internal combustion engine are used Chlorine or Fluorine for more accelerations (as alternative of Nitrous Oxide Engine)
References
- "Nitrous: Everything You Need to Know". Automoblog.net. 2011-09-27. Retrieved 2013-07-11.
- Code of Practice for Light Vehicle Modifications. Roads & Traffic Authority. 1994. ISBN 0-7310-2923-2.
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