Open Loop Cam Control

[Vlad]

Can i run the Mivec system on an EVO in open loop mode, on one of the spare outputs. Calibrate it, find the minimum and the maximum duty cycles that it responses to, and make a auxiliary table with what values I need. Kind like a classic on off system, just smoothed out a bit through the rpm range.
We have a Evo 4-8 ecu, that doesn't have cam control active. And if I manage to make it work, I can fit M84 Ecu's on Evo 9's, just for racing applications. Thank you.

[David Ferguson]

How will you account for temperature & viscosity changes?

While I don't have any experience with the Mivec specifically, I would be doubtful that you could make this work well. Also, the cam position has a big effect on the fueling required, so if the cam isn't where you think it is, the fueling will likely be off.

I predict drivability issues.

[Vlad]

I will give it a try thow....and let u guys know how it went

[mrsaturn7085]

I doubt this will work as cam control doesn't work the same way boost control does - cam control will have a center PWM value that holds cam position steady and any variance up or down will cause a rate of change (not a 'move' to a fixed target timing value).

Think of it this way:

With boost control, if you want 150 kPa at a given load cell, you command 50% duty.

With cam control, if you want 20 deg advance at a given load cell, you look at your center value, current cam advance, current load cell, and do the following:

Adjust duty away from the center value for a set time, then return to the center value.

Without a feedback loop, predicting the 'away from center value' time, or even implementing control like that, will be impossible.