During the last couple of weeks I’ve been tuning the ignition advance table on the MegaSquirt ECU.
Everytime I make some changes to the spark advance map, I save it as a backup, so I can always compare it to the previous advance numbers I used.
Up to now I’ve saved upto 20 ignition tables already, with almost each and everyone of them improving the engine’s performance.
Along with the ignition settings, I’ve also included Cold Dwell Advance into the mix, and (Low) Battery Voltage Dwell-compensation.
This means that with a cold engine (coolant), the ECU adds a little timing across the entire spark advance map, and gradually decreases the added advance until the engine is fully warmed up.
The Low voltage dwell compensation is used when battery voltage is low, like during starting. At this point the ECU will add extra dwell time to the coil, to keep the spark-intensity the same and provide good ignition.
Tuning the ignition table is great fun with the LPG Propane fueled engine.
The engine currently feels ‘light’ accelerating through it rpm and load(vacuum)-ranges.
I’ve recently also added/hooked up an Intake temp sensor to the ECU, only the sensor itself is currently located in the airfilter housing, as I wanted to find out how much the air temperature fluctuates during driving.
Next to that the already installed Innovate MTX-L AFR gauge is also connected to the MegaSquirt-3 Extra ECU now.
Below’s a screenshot of the one of the latest spark advance tables I’m running.