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Lightspeed Plasma III

bomber_JB

Active Member
My Lightspeed Plasma III is installed and wired except for connecting the Primary Ignition Wires (Section 2.3) to the coils. I've read Chapter 5.1 Phasing and that makes perfect sense. Looking forward to that.

I understand that on Plasma III systems (RG400) that the shield is not a ground.
I understand the timing magnets on the ring gear and their interaction with the sensor.

I don't understand the following from Section 2.3 "Polarity at the coils does not matter". The coils have a +/- on them. For sake of discussion let's talk about the coil that feeds #1 and #2 cylinders. If I wire the RG400 one way and the engine runs then if polarity doesn't matter I can switch the leads on that coil and engine will also run?

Doesn't the ignition have to know which lead (center or shield) of the RG400 goes to cyl #1 to fire it in compression and wait 180 degrees to fire #2. Does the ignition fire #1 and #2 at the same time with #1 in compression and #2 in exhaust? I can't envision it doing that but maybe it does.

Need help in understanding this part of the ignition.

Thanks,

Jerry
 
+1 Both plugs fire together. My understanding is that, the spark jumps from center electrode to ground electrode on one plug, the other, the spark jumps from ground electrode to center electrode.
 
Does the ignition fire #1 and #2 at the same time with #1 in compression and #2 in exhaust? I can't envision it doing that but maybe it does.

Need help in understanding this part of the ignition.

Thanks,

Jerry

Yes. this is called wasted spark and is very common on aftermarket ignition systems. No negative consequence with firing a plug while the cylinder is on the exh stroke. It is also true that single wasted spark coils are not polarity sensitive. A coil works like a matching transformer. Energy moves from primary to secondary winding via magnetism and not electricity and therefore not polarity sensitive. The magnetic field generated by the primary winding is the same, regardless of which direction the electrons are flowing. I believe this is only true for coils made from composite materials and epoxy bedded. The old steel coils are different, as there may be an internal bridge between the case and one of the leads.

4 or 6 cyl coils ARE polarity sensitive because the hot is paralleled for multiple coils in the pack.

Larry
 
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