Saab Direct Ignition

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B204L engine with red DI module. SaabB204engine.jpg
B204L engine with red DI module.

Saab Direct Ignition is a capacitor discharge ignition developed by Saab Automobile, then known as Saab-Scania, and Mecel AB during the 1980s.

Capacitor discharge ignition

Capacitor discharge ignition (CDI) or thyristor ignition is a type of automotive electronic ignition system which is widely used in outboard motors, motorcycles, lawn mowers, chainsaws, small engines, turbine-powered aircraft, and some cars. It was originally developed to overcome the long charging times associated with high inductance coils used in inductive discharge ignition (IDI) systems, making the ignition system more suitable for high engine speeds. The capacitive-discharge ignition uses capacitor discharge current to the coil to fire the spark plugs.

Saab Automobile automotive brand manufacturing subsidiary of NEVS

Saab Automobile AB was a manufacturer of automobiles that was founded in Sweden in 1945 when its parent company, SAAB AB, began a project to design a small automobile. The first production model, the Saab 92, was launched in 1949. In 1968 the parent company merged with Scania-Vabis, and ten years later the Saab 900 was launched, in time becoming Saab's best-selling model. In the mid-1980s the new Saab 9000 model also appeared.

Mecel was a software and systems consulting firm, specializing in the automotive industry. The company has offices in Gothenburg and has approximately 120 employees.

Contents

It was first shown in 1985 and put into series production in the Saab 9000 in 1988. One of the first instances of using the system was for a Formula Three racing engine (on B202 basis) developed with the help of engine builder John Nicholson, first shown in the spring of 1985. [1] The system has been revised several times over the years. The ignition system together with the ignition coils form a single transformer oil filled cassette (or two cassettes in the case of a V6 engine) which is placed directly on the spark plugs, without the need for a distributor.

Saab 9000 car model manufactured by Saab

The Saab 9000 is an executive car that was produced by the Swedish company Saab from 1984 to 1998. Representing the company's foray into the executive car scene, it was developed as a result of the successes of the turbocharged 99 and 900 models. The 9000 remained in production until it was replaced by the Saab 9-5 in late 1997, although some final cars were produced into 1998.

Formula Three race car class

Formula Three, also called Formula 3 or F3, is a class of open-wheel formula racing. The various championships held in Europe, Australia, South America and Asia form an important step for many prospective Formula One drivers. Formula Three has traditionally been regarded as the first major stepping stone for F1 hopefuls – it is typically the first point in a driver's career at which most drivers in the series are aiming at professional careers in racing rather than being amateurs and enthusiasts. F3 is not cheap, but is regarded as a key investment in a young driver's future career. Success in F3 can lead directly to a Formula 2 seat or even a Formula One test or race seat.

Saab H engine redesign of the Saab B engine

The Saab H engine is a redesign of the Saab B engine, which in turn was based on the Triumph Slant-4 engine.

It was later implemented with the Saab Trionic Engine Management Systems as one of the first ion sensing ignition system on a production car. The system puts a low voltage over the spark plugs when they are not fired to measure ionization in the cylinders. The ionic current measurement is used to replace the ordinary cam phase sensor, knock sensor and misfire measurement function.

Trionic is an innovative engine management system developed by Saab Automobile, consisting of an engine control unit (ECU) that controls 3 engine aspects:

  1. Ignition timing,
  2. Fuel injection
  3. Acts as a boost controller.
Voltage difference in the electric potential between two points in space

Voltage, electric potential difference, electric pressure or electric tension is the difference in electric potential between two points. The difference in electric potential between two points in a static electric field is defined as the work needed per unit of charge to move a test charge between the two points. In the International System of Units, the derived unit for voltage is named volt. In SI units, work per unit charge is expressed as joules per coulomb, where 1 volt = 1 joule per 1 coulomb. The official SI definition for volt uses power and current, where 1 volt = 1 watt per 1 ampere. This definition is equivalent to the more commonly used 'joules per coulomb'. Voltage or electric potential difference is denoted symbolically by V, but more often simply as V, for instance in the context of Ohm's or Kirchhoff's circuit laws.

Ionization or ionisation, is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons, often in conjunction with other chemical changes. The resulting electrically charged atom or molecule is called an ion. Ionization can result from the loss of an electron after collisions with subatomic particles, collisions with other atoms, molecules and ions, or through the interaction with electromagnetic radiation. Heterolytic bond cleavage and heterolytic substitution reactions can result in the formation of ion pairs. Ionization can occur through radioactive decay by the internal conversion process, in which an excited nucleus transfers its energy to one of the inner-shell electrons causing it to be ejected.

Direct Ignition Cassette

The spark plugs are directly coupled to the "DIC" (or "IDM") which houses the ignition coils and electronics that measure cylinder ionization for use by the Trionic engine management system.

See also

Saab 9-3 car model

The Saab 9-3 is a compact executive car that was originally developed and manufactured by the Swedish automaker Saab.

Related Research Articles

Ignition magneto

An ignition magneto, or high tension magneto, is a magneto that provides current for the ignition system of a spark-ignition engine, such as a petrol engine. It produces pulses of high voltage for the spark plugs. The older term tension means voltage.

A spark plug is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the engine. A spark plug has a metal threaded shell, electrically isolated from a central electrode by a porcelain insulator. The central electrode, which may contain a resistor, is connected by a heavily insulated wire to the output terminal of an ignition coil or magneto. The spark plug's metal shell is screwed into the engine's cylinder head and thus electrically grounded. The central electrode protrudes through the porcelain insulator into the combustion chamber, forming one or more spark gaps between the inner end of the central electrode and usually one or more protuberances or structures attached to the inner end of the threaded shell and designated the side, earth, or ground electrode(s).

Petrol engine internal combustion engine designed to run on gasoline

A petrol engine is an internal combustion engine with spark-ignition, designed to run on petrol (gasoline) and similar volatile fuels.

An ignition system generates a spark or heats an electrode to a high temperature to ignite a fuel-air mixture in spark ignition internal combustion engines, oil-fired and gas-fired boilers, rocket engines, etc. The widest application for spark ignition internal combustion engines is in petrol (gasoline) road vehicles: cars and motorcycles.

Distributor device in the ignition system of an internal combustion engine

A distributor is an enclosed rotating shaft used in spark-ignition internal combustion engines that have mechanically-timed ignition. The distributor's main function is to route secondary, or high voltage, current from the ignition coil to the spark plugs in the correct firing order, and for the correct amount of time. Except in magneto systems, the distributor also houses a mechanical or inductive breaker switch to open and close the ignition coil's primary circuit.

General Motors 54° V6 engine

General Motors' Opel subsidiary in Europe designed a compact V6 engine with an unusual 54° vee angle. It was an iron block/aluminum head DOHC design with 4 valves per cylinder. All 54° engines were assembled at Ellesmere Port in England.

The wasted spark system is an ignition system used in some four-stroke cycle internal combustion engines. In a wasted spark system, the spark plugs fire in pairs, with one plug in a cylinder on its compression stroke and the other plug in a cylinder on its exhaust stroke. The extra spark during the exhaust stroke has no effect and is thus "wasted". This design halves the number of components necessary in a typical ignition system, while the extra spark, against much reduced dielectric resistance, barely impacts the lifespan of modern ignition components. In a typical engine, it requires only about 2–3 kV to fire the cylinder on its exhaust stroke. The remaining coil energy is available to fire the spark plug in the cylinder on its compression stroke.

The Trionic 8 is an advanced engine management system in the Trionic series, created by Saab Automobile. It is used in both Saab 9-3 and Opel Vectra vehicles, and is available with 150, 175 and 210 horsepower (160 kW) engines. It will also be used for a flexifuel version starting production spring 2007. Saab Trionic T8 has been developed by Saab and is a very advanced engine management system. The Engine Control Module (ECM) is used principally to regulated the air mass, fuel and ignition timing.

Lean-burn refers to the burning of fuel with an excess of air in an internal combustion engine. In lean-burn engines the air:fuel ratio may be as lean as 65:1. The air / fuel ratio needed to stoichiometrically combust fuel, by contrast, is 14.64:1. The excess of air in a lean-burn engine emits far less hydrocarbons. High air–fuel ratios can also be used to reduce losses caused by other engine power management systems such as throttling losses.

Automatic Performance Control

Automatic Performance Control (APC) was the first engine knock and boost control system that was introduced on turbo charged Saab H engines in 1982 and was fitted to all subsequent 900 Turbos through 1993, as well as 9000 Turbos through 1989.

Alfa Romeo Twin Spark engine

Alfa Romeo Twin Spark (TS) technology was used for the first time in the Alfa Romeo Grand Prix car in 1914. In the early 1960s it was used in their race cars to enable it to achieve a higher power output from its engines. And in the early and middle 1980s, Alfa Romeo incorporated this technology into their road cars to enhance their performance and to comply with stricter emission controls.

Ignition coil induction coil in an automobiles ignition system that transforms the batterys low voltage to the thousands of volts needed to create an electric spark in the spark plugs to ignite the fuel

An ignition coil is an induction coil in an automobile's ignition system that transforms the battery's low voltage to the thousands of volts needed to create an electric spark in the spark plugs to ignite the fuel. Some coils have an internal resistor, while others rely on a resistor wire or an external resistor to limit the current flowing into the coil from the car's 12-volt supply. The wire that goes from the ignition coil to the distributor and the high voltage wires that go from the distributor to each of the spark plugs are called spark plug wires or high tension leads. Originally, every ignition coil system required mechanical contact breaker points and a capacitor (condenser). More recent electronic ignition systems use a power transistor to provide pulses to the ignition coil. A modern passenger automobile may use one ignition coil for each engine cylinder, eliminating fault-prone spark plug cables and a distributor to route the high voltage pulses.

Ignition timing

In a spark ignition internal combustion engine, Ignition timing refers to the timing, relative to the current piston position and crankshaft angle, of the release of a spark in the combustion chamber near the end of the compression stroke.

Trionic T5.5 is an engine management system in the Saab Trionic range. It controls ignition, fuel injection and turbo boost pressure. The system was introduced in the 1994 Saab 900 with B204L engine.

The Trionic T5.2, an advanced engine management system in the Trionic series, was introduced in Saab 9000 year 1993 and was discontinued the same year. This engine management system was used on the "long block" engines. It was superseded by the Trionic T5.5 engine management system.

High tension leads type of a power cable which is used in the spark plug

High tension leads or high tension cables or spark plug wires or spark plug cables are the wires that connect a distributor, ignition coil, or magneto to each of the spark plugs in some types of internal combustion engine. "High tension lead" or "cable" is also used for any electrical cable carrying a high voltage in any context. Tension in this instance is a synonym for voltage. High tension leads, like many engine components, wear out over time. Each lead contains only one wire, as the current does not return through the same lead, but through the earthed/grounded engine which is connected to the opposite battery terminal high tension may also be referred to as HT.

References

  1. "Brefs" [In brief]. Echappement (in French). Paris, France: Michael Hommell (198): 23. April 1985.