Converting to coil on plug

[19963.4lsr5]

Has this ever been done before?

Since the 5vzfe is wasted spark it seems like a coil on plug from a mopar or ford would work for the sparkplug that's not under the coil pack. Just splice into the 12v connector that fires the OEM coil pack or a coil on plug on both plugs and tapping off the 12v connector and feed both coils. They would fire together with the factory setup anyway.

I guess that will depend on if they fit in the spark plug tube.

 

[JohnsD90]

Why?

 

[19963.4lsr5]

For me I have spare COP's and would try and use them if one of the coils went bad on the 3.4

Just thinking.............

I do have a spare Toyota coil I picked up at the junkyard though. Just like COP. Its simple and very forgiving.

 

[Jake.Werecat]

My same thought exactly!
Why? Because I dislike wasted spark design with 3 coil packs. But mainly because I can.
Converting to true COP is difficult, as there are only 3 ignition timing signals going from the ECU. It would be necessary to split those 3 signals to 6 signals firing twice less often, the split decision would have to be made using some 3rd party circuit fed with the signal from camshaft sensor.
BUT
Converting to wasted COP - i.e. 6 single COPs but still fired simultaneously in pairs should be fairly easy. There are two possible ways of doing that.
Using 6 2-pin COPs and connecting the pairs in parallel to the OEM ignition module OR
ditching the ignition module, ale using 6 4-pin COPs from Lexus, which give the IGF return signal back to the ECU.
It's only theory for now, but I'm eager to try that in practice really soon. I'm swapping my 3.slow to 5VZ-FE, so I'll have a new engine to play with

 

[brillo_76]

Oh. I am I liking this thread. Great thought. I am sure circuitry could be made to make it a non wasted as it just timing. So if this time can be determined. You could use capacitor to fire the 2nd coil at the proper time.

All you need is a passenger valve cover to bolt coils to it. Then the plugs to split the coil fire signal and the correct capacitor to delay the signal time.

Or circuitry to send the signal one pulse to this coil then the next signal to the other. As 2 options I am thinking to eliminate the wasted spark system on the v6.

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[rdruss]

Huh?

 

[brillo_76]

Huh?

The OP is talking about making the v6 engines have a coil on top of each cylinder and replace the wasted spark system. I kinda like the theory as it would make the spark plugs last a lot longer.

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[19963.4lsr5]

Holy dug up from the past.

I’ve seen it done to some Hondas, but I never pursued it.

My only concern is the drivers/transistors in the ICM not being able to handle the extra current. It’s load would be doubled.

I also thought of mounting 3 MSD6 boxes and using the coil signal it trigger the MSD boxes and fire msd’s wasted spark coils.

Another thing holding me back is not having a spare engine harness.


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[brillo_76]

Holy dug up from the past.

I’ve seen it done to some Hondas, but I never pursued it.

My only concern is the drivers/transistors in the ICM not being able to handle the extra current. It’s load would be doubled.

I also thought of mounting 3 MSD6 boxes and using the coil signal it trigger the MSD boxes and fire msd’s wasted spark coils.

Another thing holding me back is not having a spare engine harness.


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What year harness you Need? I have a auto 1997 here I chopped transmission connector etc off of. I can give you for the cause. I saw this was an old one 2013

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[JohnMc]

I've converted a Volvo motor to coil-on-plug before - it was a 16V redblock with deep well plugs (like the 4Runner) and I used some Toyota Corolla coil-on-plugs which had nice logic level triggers (along with being self powered, no need for an ignition module). But that was with a full standalone ECU (MS3X).

I'm not sure the juice (what juice) here is worth the squeeze. Since the factory ECU only fires three ignition channels, you're going to be wasted spark with twice as many coild. And a circuit which can accurately trigger the correct coils back and forth based on the ECU's single signal for both won't be simple. Certainly doable, but I'd generally think you're going to end up with something that is less reliable and, at best, runs exactly like an unmodified engine.

 

[brillo_76]

I've converted a Volvo motor to coil-on-plug before - it was a 16V redblock with deep well plugs (like the 4Runner) and I used some Toyota Corolla coil-on-plugs which had nice logic level triggers (along with being self powered, no need for an ignition module). But that was with a full standalone ECU (MS3X).

I'm not sure the juice (what juice) here is worth the squeeze. Since the factory ECU only fires three ignition channels, you're going to be wasted spark with twice as many coild. And a circuit which can accurately trigger the correct coils back and forth based on the ECU's single signal for both won't be simple. Certainly doable, but I'd generally think you're going to end up with something that is less reliable and, at best, runs exactly like an unmodified engine.

I just like the concept of it. If it's just a fire signal. All we have to do is route the signal every other time to each cylinder. Being it's only the same coil firing. The coil load is identical. It's just a every other pulse switch the the other coil.

It's not that complex of a logic circuit. Relays can react fast enough so it has to be done via logic circuit

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[19963.4lsr5]

I was happy firing both plugs at the same time.

It eliminates plug wires going bad and the spark gap is only .045” instead of .090”. Which would be an improvement for the supercharger crew.

A single coil on plug will fire a huge gap without a missfire.


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[brillo_76]

I was happy firing both plugs at the same time.

It eliminates plug wires going bad and the spark gap is only .045” instead of .090”. Which would be an improvement for the supercharger crew.

A single coil on plug will fire a huge gap without a missfire.


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You can do that as well. If all it is coming to the coil is a firing signal just paralleling the wiring to the second coil is all that should be required and basically just a homemade harness that plugs into the coil signal wires that have a set of plugs for the passenger with wiring and plugs for the 2nd coil.

Plus you need a way to hold the coils in place with a different valve cover or homemade brackets because that's the side with the oil filling plug as well.

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[WeakSauz]

Very common upgrade on other Toyota platforms such as the 1UZFE, which runs wasted spark from the factory.

The Audi R8 sports car COPS snap right into that engine, for example.


Now, the hard part is that converting to COP sometimes required a standalone engine management system.

 

[Jake.Werecat]

Done

 

[Dmod8]

This is a wild concept, I cant wait to see more of it.

 

[phattyduck]

I wouldn't do this unless you are driving each coil as intended... I single coilpack is only meant to fire once every 720* of crank rotation and firing it twice as often can/will overheat it. The wasted-spark coilpacks are designed for twice the 'load' that the smaller single coils designed for.

So, with a standalone this is a good idea. With the stock ECU, there is 0 reason to do this.

-Charlie

 

[Dirty Dude]

That's a potential problem, although I would be surprised if the safety factor for the coil duty cycle was only 2. Some aftermarket coils at least have the specs available. For example, the IGN-1A "smart" coils are limited to about 40%. That allows them to be used on a low-ish rpm 4cyl distributor setup without overheating, albeit at significant expense to dwell time and spark energy.

And then there's the issue of why go to the trouble of retrofitting COPs just to fire them in wasted spark? Spark plug wires aren't that bad.

Conceivably, running COP ignition would allow the use of regular single-ground spark plugs in a 5VZ. By extension, this would allow the use of double platinum or platinum-iridium plugs that last several times longer than the stock Densos.

The engine already has the hardware to allow sequential fuel injection which is the same stuff needed for sequential spark, but the problem is that a stock ECU doesn't have six sequential spark outputs.

I imagine it would be possible to build a sequencer that splits each coil circuit into two and only fired one coil at a time like a flip-flop. It would have to have at least a cam signal of some kind in order to know which cylinder had to be fired next.

 

[stunt2]

That's a potential problem, although I would be surprised if the safety factor for the coil duty cycle was only 2. Some aftermarket coils at least have the specs available. For example, the IGN-1A "smart" coils are limited to about 40%. That allows them to be used on a low-ish rpm 4cyl distributor setup without overheating, albeit at significant expense to dwell time and spark energy.

And then there's the issue of why go to the trouble of retrofitting COPs just to fire them in wasted spark? Spark plug wires aren't that bad.

Well, actually they ARE bad. I owned Lancer EVO years ago. It's 4 banger has similar ignition as 4runners, - 2 coils and 2 wires, so it's waisted spark too. Converted it to full coil on plug setup on stock ecm and wiring (btw, I used RAV4 coils for it ) and the difference was night and day. Literally night and day ! So much more smooth driveability on low rpm, more power, more torque. It was like driving another car. And it's about off boost, not talking about on boost driveability )
Can't see any reason why it'll not be good for 4R's

 

[JohnMc]

Yeah, it was a fairly common practice early on the transition distributors to COP setups. A wasted spark cop/wire to paired cylinder setup. My Miata (factory turbo version) has a similar setup.

There really is no actual drawback to this setup.