Honda K20 coils - are these +ve edge(dwell)?

Hi I’ve retro fitted Honda K20 coils to my engine - so I don’t burn them up…. are these +ve edge(dwell) in the ECU setup?

thanks in advance!

Spark edge will be falling with those coils.

So I have the option of -ve edge(dwell), +ve edge(dwell), -ve edge(pulse), +ve edge(pulse)

It doesn’t actually say falling which confused me.

It does say “ignition systems like Honda, that use inverted dwell, select +ve edge (dwell)”. - so I presume this is what I use?

thanks!

I believe they are saying +ve Edge (start of dwell) -- this is the rising edge

-ve Edge (pulse) -- this is the falling edge when the spark pulse will be triggered.

Perhaps you should look in whatever documentation you have to see what the definition of "dwell" and "pulse" is.

Thanks David - unfortunately this is all the info that is given. I’ve emailed a dealership so hopefully they will be back in touch!

Hi I found an info box in the autronic ECU for this - does this clarify what setting I should use for the K20 coil?

Ignition trigger edge.

"

!!WARNING COILS WITH DWELL CONTROL!!

MAKE SURE POWER IS REMOVED FROM THE COILS WHEN SETTING UP. MAKE SURE THAT THE ECU BATTERY VOLTAGE, IGNITION DWELL TABLE TIME, IGNITION TRIGGER EDGE AND NUMBER OF IGNITION O/PS IS SETUP AND CHECKED WITH MULTI-METER BEFORE APPLYING POWER BACK TO THE COILS. INCORRECT SETTINGS WILL DAMAGE COILS.

ALWAYS SET TO IGNITION MANUFACTURE SETTINGS.

-ve edge (DWELL) ______-_

@0Volts=Static state

@12Volts=Dwell charge state

"008 modules"

"-ve edge dumb ignitors"

"Subaru01..05"

+ve edge (DWELL) ------_-

@12Volts=Static state

@0Volts=Dwell charge state

"MSD DIS-2 DIS-4" Dwell time 2.5msec

-ve edge (PULSE) ------_-

@12Volts=Static state

@0Volts=Pulse state

"Autronic CDI"

+ve edge (PULSE) ______-_

@0Volts=Static state

@12Volts=Pulse state

"MSD 6 family" Pulse time 2.5msec

NOTE

"Ignition dwell/pulse table" is used both in dwell or pulse mode. "

Coils that charge when the signal goes high (rising edge), then spark when the signal goes low (falling edge), are called falling edge spark.

As I mentioned, these are falling edge spark coils.

In most ECUs, you're asked when the coils spark, so you'd say falling edge or VE-.

Autronic asks backwards of most, by asking when the coils start charging rather than when they discharge, so you'd say VE+ (rising) is when dwell starts.