Saab Direct Ignition
Encyclopedia
Capacitor discharge ignition
Capacitor discharge ignition 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...
system developed by Saab Automobile
Saab Automobile
Saab Automobile AB, better known as Saab , is a Swedish car manufacturer owned by Dutch automobile manufacturer Swedish Automobile NV, formerly Spyker Cars NV. It is the exclusive automobile Royal Warrant holder as appointed by the King of Sweden...
, then known as Saab-Scania, and Mecel AB
Mecel
Mecel Mecel is a software and systems consulting firm, specializing in the automotive industry. The company has offices in Gothenburg and has approximately 120 employees.- History :...
during the 1980s.
It was first shown in 1985 and put into series production in the Saab 9000
Saab 9000
The Saab 9000 is an automobile that was produced by the Swedish company Saab from 1984 to 1997. The 9000 was replaced by the 9-5 in the late 1997....
in 1988. The system has been revised several times over the years and is still in production today. The ignition system
Ignition system
An ignition system is a system for igniting a fuel-air mixture. Ignition systems are well known in the field of internal combustion engines such as those used in petrol engines used to power the majority of motor vehicles, but they are also used in many other applications such as in oil-fired and...
together with the ignition coils form a single transformer oil
Transformer oil
Transformer oil or insulating oil is usually a highly-refined mineral oil that is stable at high temperatures and has excellent electrical insulating properties. It is used in oil-filled transformers, some types of high voltage capacitors, fluorescent lamp ballasts, and some types of high voltage...
filled cassette (or two cassettes in the case of a V6 engine) which is placed directly on the spark plug
Spark plug
A spark plug is an electrical device that fits into the cylinder head of some internal combustion engines and ignites compressed fuels such as aerosol, gasoline, ethanol, and liquefied petroleum gas by means of an electric spark.Spark plugs have an insulated central electrode which is connected by...
s, without the need for a distributor
Distributor
A distributor is a device in the ignition system of an internal combustion engine that routes high voltage from the ignition coil to the spark plugs in the correct firing order. The first reliable battery operated ignition was developed by Dayton Engineering Laboratories Co. and introduced in the...
.
The system puts a low voltage over the spark plugs when they are not fired to measure ionization
Ionization
Ionization is the process of converting an atom or molecule into an ion by adding or removing charged particles such as electrons or other ions. This is often confused with dissociation. A substance may dissociate without necessarily producing ions. As an example, the molecules of table sugar...
in the cylinders. The ionic current measurement is used to replace the ordinary cam phase sensor, knock
Engine knocking
Knocking in spark-ignition internal combustion engines occurs when combustion of the air/fuel mixture in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front.The...
sensor
Sensor
A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated...
and misfire measurement function.
Direct Ignition Cassette
In the illustration to the right, 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 TrionicTrionic
Trionic is an engine management system developed by Saab Automobile, consisting of an engine control unit that controls 3 engine aspects:# Ignition timing,# Fuel injection# Acts as a boost controller.Hence the numerical prefix 'Tri' in Trionic...
engine management system.
See also
- Direct & Distributorless Ignition
- Saab H engineSaab H engineThe Saab H engine is a redesign of the Saab B engine. Despite the name it is not an H engine, but a slanted inline-4. The H engine was introduced in 1981 in the Saab 900 and was also used in the Saab 99 from 1982 onwards and the Saab 90. It continued in use in the 900/9-3, 9000, and 9-5...
- Saab 900Saab 900The Saab 900 was a car produced by Saab Automobile from 1978 until 1998 in two generations. The first generation from 1978 to 1993 is known as the "classic"; the generation from 1994 to 1998 is known as the "new generation" ....
NG (2nd Generation 900, 1994-1998) - Saab 9-3Saab 9-3The first generation 9-3, a substantially improved 'new-generation' Saab 900 was launched in 1998 for the 1999 model year. Saab claimed that 1,100 changes were made, including a revised suspension in an attempt to tighten up the handling characteristics of its predecessor, the Saab 900...
(1st Generation, 1999-2002)