Dwell time of COPs

matthud

I am using the coil on plug units from the 2007 L61/LE5 on my stand alone ECU. I was hoping someone might know the stock dwell time on these coils. These are the coils I am referring to:

si_c1978

tricky!
they were probably managed by an ignition control module somewhere which varies the dwell, protecting the coils from over saturation.
we in the uk have a cassete type coil pack that runs wasted spark.
you can see this in vockys webcon post.
i am also using the same technique, i have removed the control module and wired direct to coil.
my dwell settings are 3.4m/s and 0.7m/s max spark duration with no problems SO FAR! its only 2 weeks!
3.6m/s is regarded as a safe start point and then(while cruising connected to a lap top) you can turn it down 0.2m/s at a time until you feel a miss then bring the value up 0.2 m/s or so.
hope this helps.

si_c1978

forgot to mention if you are running an ignition control module/they are built into the cop's the setup is different, and i gather (tho im not sure) that you can trigger the coils with 0.1m/s as the icm varies the dwell itself

matthud

I believe that the stock PCM does all the control on these coils. They are connected straight back to the PCM and nothing else, other than power. Prior to 2007 ours had the cassette too. Then they switched over. The 2.4 here uses the COPs too.

I tried running them at 2 ms dwell, after running the engine for 5 minutes they were almost too hot to touch. So I am worried that I am over driving them, but can't find any info on them.

si_c1978

have a search or ask the question on the megasquirt forums(free to join even if your not using them)
im sure it said on there about the 0.1 ms if using icm as it only needs the signal as it sorts dwell itself. again im not 100% sure.
incidentaly mine get hot but the drivers only warm as i should imagine engine temp is a factor due to location.

matthud

I figured out why my coils were getting so warm. They have built in ignitors, I had my ECU configured to use the coil drivers in the ECU. So the output to the coils was inverted. So they were actually charging when they should have been off. It also had my spark happening 180* out, because they were triggering on the edge of the pulse.

si_c1978

oops!

matthud

You're telling me. The one bad COP didn't help the situation. But once I got that sorted out, the 40* of retarded timing also was figured out.