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I tend to agree. As we know, the plugs are used to help measure ionization. From eeuroparts.com "How Ionization Sensing Works in Saab Engines
When engineers realized they could go further, the gears at SAAB were turning. As early as the mid 80’s, the technology that Saab Trionic is built on was being developed, a system that wins the engine management 1-up game handily. Here’s why:
Saab Trionic PartsThe knock sensor cannot tell what cylinder is knocking. When it registers a knock, it signals to retard timing and the entire engine is affected. Because of the way consumer grade engines work, no two combustion cycles will be the same. The Saab performance part for Saab engine management, the Trionic does things fundamentally differently. In combination with a critical component called a Direct Ignition Cassette (oh, you’ve heard of it?), the computer is able to very precisely control everything that is going on with each individual cylinder and Saab engine parts such as the spark plugs. The critical difference from a knock sensor is the system’s ability to detect the ionization in each cylinder and relay that info back to the computer individually.
To do this, the computer uses the DIC to send a signal between the Saab electrical parts such as the spark plug electrodes to measure the electrical resistance of the air in between. Depending on how well the flame envelope is burned, and what is left over after the main combustion, the computer can deduce a lot. It’s like the DIC is telling the ECU “On the sensing phase of that last firing in cylinder number 3, I got 734.2 ohms, and on this one I got 729.8 ohms” Then the ECU can return with, “I’d prefer a range in the 600s, for the next combustion I will retard timing by .5 deg, let’s see where that gets us”*.
This happens many times a second, for almost the entire time the engine is running. This way, no matter what quality or octane fuel you use, no matter the altitude, humidity, or temperature of air…. the system will always be able to dial in exactly the turbo pressure, spark timing, and fuel injection timing.
The only time that this active timing doesn’t take place is when you just start the engine. Upon initial startup on a Trionic engine, all Saab engine parts, including the spark plugs are firing at the same time, using a much older process called “wasted spark“. That just means on cylinders that aren’t combusting (exhaust stroke), the spark is ‘wasted’. During this phase, Saab Trionic is getting its bearings. Soon after, the process switches to sequential ignition and the process above starts. The most intricate Saab parts; the fuel injection system and turbo pressure are also controlled with this information, hence TRIonic, but that is a discussion for later. Additionally, when the engine is shut off, the Saab engine management computer sends a hefty dose of high powered spark across all the plugs for a second or two in Trionic 5 cars. This cleans the Saabs electric current systems plugs to prepare for the next cold start."
posted by 207.112.42...
12
, Thu, 22 Jun 2023 16:33:22
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