Something to think about for those who already have this on their cars: the OEM coil has nice closed loop connection for secondary winding/coil. Spark energy travels from coil through spring in short boot (cylinder 2 or 4) to spark plug center electrode, jumps (spark) to ground electrode, travels along aluminum head to other ground electrode (cylinder 1 or 3), jumps (spark) to center electrode, travels through spark plug to longs spark plug wire and back to coil. All solid connections.

Using COP, the spark energy travels down to spark plug, jumps (spark) from center electrode to ground electrode, travels along aluminum head through what looks like exhauat (or intake, I can't tell the actual location) cam sensor housing, through grounding wire, and back to coil. I wonder if the ground wire should be beefed up, since we have two sparks going through this at the same time (1&4 and then 2&3) every half of crankshaft revolution to return to the coils?

 

the engine has a few different ground points. So far people only seem to report improvements when installing a C.O.P. setup, and I haven't witnessed any component degradation so apparently the wiring is all good. Plus the spark energy is very high voltage low current so that makes it even less of a thing.

 

Thanks for this! I was trying to find where my fuel pump wiring is going on top of fuel tank and just found where it comes into cabin!!

 

Depends on the type of coil used.
Traditional coils used with distributors (a 3 terminal auto transformer, only 1 winding), the circuit is completed through the battery(Ht terminal, to plug, to engine block, to ground, through the battery, to coil primary +12, back to coil secondary).

If it's a COP coil with a 3 pin connector, it's usually 12v, input and primary earth.
If it's got a 4 pin connector then it's also got a secondary earth (completes the circuit) and it's usually configured as an isolating transformer with no connection between primary and secondary windings.
Like the ign 1A coils where all the online diagrams for them are wrong.


Factory wasted spark coils are best unless you've got an aftermarket ECU with 4 coil drivers.
It's totally pointless firing blanks every second spark with COP.
You're still firing every coil once every 360 deg, same as with wasted spark.

 

Deleted to avoid confusion. Later posts are more accurate

 

Here's a diagram of a Toyota coil.


https://www.google.co.nz/imgres?imgu...act=mrc&uact=8

How is the HV circuit completed?

NOT through the ground cct.
As I said above, the ground is only for the primary side, or rather to supply the igniter and to switch the primary side to.

 

Deleted to avoid confusion. Later posts are more accurate.
But rest should still stand:
The way I think of a transformer: use one voltage system and step up (or down) according to winding ratio. The transformer secondary coil is the source of power, like the battery is for the primary system. Let's assume the transformer ration is 2:1, like 50 windings for primary and 100 for secondary. When primary power is connected (to battery), the primary winding in the transformer creates a magnetic field. The electrons in the secondary winding starts flowing at same rate of magnetic field (double the winding, so double the voltage) to generate 24V. The transformer is the source of energy like the battery is for primary. If you disconnect the battery to transformer, 24V ends too.
Think of it this way, your DVD player has a transformer inside. It converts wall outlet AC to DC for circuit board inside. The electronics board inside would not see AC electricity (otherwise, why would you need a transformer?). The transformer is the power source for the circuit board. Now, realize that all the components have to connect to transformer + and - (not the AC system) to work. If you only connect to + side, the component won't operate.

 

You've got no idea and you're having to make it all up as you go.

Yes that diagram is correct and similar to other coils.

 

The post about the oem ignition system loop is correct.


The toyota ignition coil internal diagram is also correct.



The loop on the COP system works in the same way as the stock ignition does.
The reason it does not act as an isolated closed loop system is because the feedback line or second ground is not activated but left out on the Evo, unless one decides to activate it through an aftermarket ECU.



Also about the COP, it works best when a sequential type of ignition is used through an aftermarket ECU.
As a wasted spark type it performs at least as well as the dual output coils on the stock or aftermarket ecu.

The advantage here is that, it allows one to incorporate stronger coils than the dual output oem ones, at less than half the price of a set of quality uprated oem type units such as the Okada direct replacements for example. Even If one merely needs to refresh the ignition system, builds the COP system himself, it will cost even less than buying two brand new oem original mitsubishi dual output coils.








Marios

 

Mods: Sorry for going off topic this is my last response on coil paths since it doesn't matter. Lol. Feel free to clean up.
This thread is one of the better ones because the OP included a template for the spark plug cover plate and it's a complete reference.

It doesn't make sense to have both coils connect to battery 12V. Think about it or ask people who understands about transformers.

Why is there so much confusion about ground? It's because both uses engine metal. Can you imagine isolating spark plugs where there's in individual wire back to the coil? Why? Because he energy source isn't at battery. It's at coil.
Believe what you want.

Here is basic info on transformers. COP is essentially a transformer where it takes 12V and increases to 40,000V. Primary winding uses source power (12V) to generate magnetic field. Secondary windings uses magnetic field to produce spark (40,000V) but it has to close loop back to coil (transformer) or else, no electricity. Try opening your computer and cut the negative on power supply. Then try connecting a 12V battery ground to comouter board. It won't turn on because that 12V battery isn't part of the power supply loop.

https://www.electronics-tutorials.ws...er-basics.html

 

You are wrong mate as you have things confused.

I disagree with you. If you do some more searching on the right info on the matter you will see how things actually are. COP and the type of current transformation that happens withing an inductive type of coil is not the same as when done in CDI type of ignition where the type of external capacitor that is used is of a different type.


The analogy that you have used is not relevant to the subject matter.


Regarding the closed loop, as I said on my previous post, with the COP on the Evo, it happens in the same way as with the stock coils.







Otherwise, enjoy your evo.




*Forgot to say that I actually use a self made COP system on my personal Evo, for the past 7 or so years now, used both on the stock ecu and on the aftermarket one I'm using now.








Marios

 

The primary and secondary don't need isolation. All spark plugs (that I know of) are made to ground into the head, from there you just need a path to the other side of the secondary to complete the loop. It does not matter for our purposes if the primary is isolated from the secondary on that path, at least that's my understanding. It's all about node theory and voltage potentials.

 

Yes there is no actual need for isolation, but the diagram posted on a previous post is correct. That is how an inductive coil works.










Marios

 

That diagram looks like it was done by a middle school kid with paint, not an ee so color me skeptical on it's accuracy. If someone can dig up a pn on a real driver ic I'll believe the data sheet lol

 

Then your best bet is to find a denso coil and disassemble it.








Marios