[b3lha]

Originally Posted by Trevor

Kia ora Phil,

The figures recorded by Tony are valuable and I find them very interesting, particular those covering engine load.

I have a permanently installed pressure gauge registering transmission line pressure. It is clear that pressure becomes adjusted in line with torque, as is being delivered to the transmission by the engine. This observation therefore directly aligns with the engine load figures.

Has your research covered this aspect of things? If so, are you able to advise which sensors provide the signals which are computed, in order to arrive at the figure covering engine load?

Thanks in anticipation, Trevor.

Hi Trev. I am not sure exactly what you're asking.

This is my understanding of how it works on new Subaru's. Ours is probably the same but our older ECU technology cannot cope with floating point maths. Therefore there will be some constants multiplied in so that the values can be represented as integers to a certain precision.

M = Mass Airflow is measured in grams of air per second.
R = Engine Speed is measures in Revolutions per minute.

Engine Load is (M * 60) / R = grams of air ingested per revolution of the engine.

As you said, there is some kind of relationship between engine load and torque output.

With regard to the correlation you have observed between torque and transmission line pressure: Obviously engine load and torque are controlled by the throttle plate. It restricts the amount of air that the engine can ingest. Throttle position is also the most important factor that the TCU considers when deciding on the line pressure.

http://www.subaru-svx.net/forum/show...&postcount=247

If my graphs are accurate, the Sol A duty cycle levels off at 87.5% above 20% throttle.

The line pressure is not decided by the engine load. But the engine load and the transmission line pressure are both ultimately dictated by the throttle. Correlation, not Causation. But it certainly makes sense that the TCU would be designed to increase line pressure in line with the torque produced by the engine.

Does that help at all?