Hence the numerical prefix '' in Trionic. 'Ion' comes from the fact that it uses ion current measured by the spark plugs between combustion events as a sensor for knock, misfire and synchronization detection. With the ion sensing system, the ion current stream developed due to combustion can be deduced by monitoring the secondary current of the ignition coil. Using the value and wave shape of the current, after the actual spark event, the quality of the actual combustion process is determined, thus allowing the engine control unit to optimize the timing of the spark for the best engine performance while keeping emissions low on a much wider range of rpms. Since Trionic 7, the throttle and thereby the air charge is electronically controlled, but the name "Trionic" was not changed accordingly.
History
The SAAB Trionic engine management system was developed for the 9000 and 'New Generation' 900 turbocharged engines. The engine management system was first utilized on the Saab B204 and B234 "H" engines to monitor and control the fuel injection system and turbocharging pressure control. The Trionic 5.2 and 5.5 systems utilized the manifold absolute pressureMAP sensor and the intake air charge temperature sensor to calculate the fuel injection curves, while the Trionic 7 and 8 systems are mass air flow type. The two have substantial differences that prevent utilization of components between the two. Generally speaking, engine tuners prefer the easier to work with Trionic 5 systems over the Trionic 7 and 8 which are more restrictive in what can be manipulated in the software. The intellectual rights to the Trionic 5 and 7 systems were sold to BAIC, along with the Saab H Engine that it was designed for, in 2009 as part of Saab's restructuring and transfer of ownership from General Motors to Spyker.
Models and ECU information
Generally speaking, Trionic systems are shortened to indicate which version they are, e.g. T5, T7, T8, etc. The engines with T5 had red direct ignition modules which differentiate them visually from the T7 models which had a black ignition module. The ignition module on both T5 and T7 are an integral ignition coil and electronics that plugs directly onto the spark plugs without the use of spark plug wires that are typically used on most engines. SAAB Models Utilizing Trionic Engine Management System:
Many people around the world are working on reverse engineering the Trionic engine management system, by way of various open source communities. The work involves understanding the binary files stored in the ECU itself, and what changes affect the car's hardware and operation of the vehicle. The T5, T7 and T8 management systems have been successfully manipulated to allow self-tuning for enthusiasts. There also some alternative options in the way of interceptors like # Unichip that clamp the various inputs to the standard management systems, but they are restricted by the fact that fuel delivery generally cannot be easily increased as manipulation of the air-flow meter input and/or aggressive modifying of the ignition timing causes the Check Engine Light to illuminate easily due to a deviation between the expected and targeted torque and quality of emissions. It is therefore common to increase the fuel pressure across the board by using an aftermarket fuel pressure regulator when tuning is performed by these interceptor computers, and trim the fuel out instead. However, increased fuel pressure has the side-effect of affecting the engine's ability to idle due to injector lockup, and as such sometimes an alternative solution of additional injectors instead of a raised-fuel-pressure regulator is proposed. The number of cars with such complex requirements is very low, and in general a full aftermarket engine management system is used in these cases, such as Nira or MoTeC.
