I would imagine it depends heavily on RPM and commanded spark advance. My assumption is that beyond some pre-determined RPM (for the sake of discussion let's pretend it's 5000) it simply switches the ICM back on immediately after it switched off as a "best effort" type methodology. But without someone dumping the TPU ROM or a bunch more waveform captures it's all conjecture.
This is my sticking point. If it's worth doing it's worth doing correctly. To use your metaphor, there's no point building a half cocked setup here. By my reckoning there are two types of LT-1 enthusiasts - the folks who want to preserve the stock setup as cheaply as possible and the modders who want to squeeze every ounce of power out. If you're the former go buy an aftermarket opti, a new water pump, a new optical sensor, suck it up and drive for another 200,000 miles. It's a damned reliable ignition system and will make great power well into the 6500 RPM neighborhood, until your water pump s**ts the bed.
I doubt it calculates advance but simply keeps a "running" variable derived from comparing when the EST line switches off to high res pulses since low res falling edge. Maybe it's more complicated than that, but I doubt it. But ultimately, to know exactly when to start dwell the controller must know about commanded spark advance. Else it's just a "close enough" thing, which gets us back into the realm of "half-cocked".
It must, else the controller would need to duplicate a bunch of spark advance functionality that the PCM handles just fine. To do that it would need to know about MAP, TPS, ECT, knock, (need I go on?).
Yes it is.
I think I have a picture in my mind of how to do this on a single arduino "core". Hopefully I'll have a chance to build out a sketch that will demonstrate the concept before one of my 7 other projects get in the way.
Bookmarks