rusefi.com

nobody asked for this, but here's a comparison of spark sounds, running somewhere around 1000 rpm maybe, settings of max 3 spark, 2ms additional dwell. main dwell at probably around 4ms. these are GM coils with built-in igniters.

multispark: https://www.youtube.com/shorts/l0-3FadAFIo




single spark: https://www.youtube.com/shorts/euJszofUT78


multispark sounds cooler.

couple more that nobody asked for, but as i'm testing things for melting, i took a video:

250-ish rpm, cranking mode, 6 cylinder sequential ignition, and injection, but injection is simultaneous while cranking:

https://www.youtube.com/shorts/v0IeTYYb0yA


and 700-ish rpm running mode, sequential ignition and sequential injection, no longer simultaneous:

https://www.youtube.com/shorts/hcnJLM9AdGU

this is what multispark looks like on logic analyzer:

1 5 3 6 2 4 firing order


D1 = 36-2 wheel
D2 - D7 = cyl1-6 ign

maximum 3 extra spark
this is about 1000 rpm, main dwell is 4.2ms

(right click -> open image in new tab, to actually see wtf)

See also my original video of coil primary current when I implemented it:

Cool. In 2018 I modified the code on my Universal knock controller to do multispark.

I know the ignition on the modular Fords makes three sparks below 1500 RPM but I didn't investigate use for starting and idle. I was just seeing if I could do it.

There was a thread on the speedtalk forum about an inductive ignition with multispark from Pertronix, but no one had a photo of the waveform, so I decided to try my own version. I deleted the video in the link, but posted an updated version.

https://www.speed-talk.com/forum/viewtopic.php?p=723611#p723611

I could set the initial number of sparks, the dwell, and the "coil off" time. In this video, it's five sparks, with 250usec dwell and 200usec coil off time. It was all done in software, no mods to the hardware, so it's zero dollars, but I decided not to use it. Maybe I should look at it again?