igniter question (re ej20g)

[heelhooker]

I’m installing an jdm ej20g in my ’91 turbo legacy. I am using the usdm legacy ecu. The jdm engine uses a coil over plug ignition arrangement, so there are a total of four coils as opposed to only two used on the waste spark type ignition on the ej22.

Instead of using the ej22 coil pack and plug wires, I am thinking about retaining the four ej20 coils and having cylinders 1/3 and 2/4 fire simultaneously (just like the ej22 system). This would require two coils to fire at the same time. Will the igniter be able to handle this? Any other reasons this would be a bad idea?

Thanks

[vrg3]

I think it should work okay. I was thinking about this before too. I don't see why it would be functionally different from waste spark except that the spark will jump in the same direction in both cylinders, which shouldn't matter at all.

The ignitor will probably be fine if you mount it securely to something it can use as a heat sink, and use a little heatsink compound on the mating surface. You're using the EJ20G's intercooler, right? So you'll be relocating it anyway. Use a small piece of aluminum stock to make a mounting bracket; aluminum's nicely conductive.

And keep a spare ignitor in your glove box just in case. They're small, cheap, and easy to swap.

[heelhooker]

I like the heat sink idea. I'll mount it to an aluminum plate. Maybe a peltier cooler could even be set up...haha, like I'll ever get that done.

If this works, it will be nice. The seemingly simplest things like mountiing the coil pack and getting the right plug wires can turn into a big hassle.

Yeah, I'll be using the ej20 intercooler eventually. My main objective is to just get the engine running right now, so I'm just using the old vf11 with no intercooler (at stock boost). Once I get things sorted out, I'll get the intercooler on. I need to get a pump for it anyway.

[vrg3]

Something like a Peltier junction would be overkill and too complex, in my opinion. If you want, use a heat sink with fins, but just a piece of aluminum stock should be fine.

Using a coil pack wouldn't be as much of a hassle as it might initially seem. You could just get some bulk ignition wire and make your own spark plug leads for any coil pack mounting position, like on a strut tower or something. Or just epoxy some studs onto the intake manifold to hold the coil pack.

If you're not intercooling you will probably be okay using the stock steel ignitor mounting bracket. Just make sure the ignitor and bracket mate nicely and smear some heat sink compound in between. And, like I said, keep a spare ignitor in the glove box just in case.

[heelhooker]

It does not work. There is a spark, but it is too weak.

I guess if the current out of the igniter is limited, this would make sense, as current through each loop would be 1/2 of the limit.

[vrg3]

I posted this in your other thread, but maybe you could use two stock ignitors, so each channel of each ignitor is only responsible for one coil.

These are the ignitor pinouts:

Code: Select all

If you look at the connector on the ignitor head-on, the pins are arranged like this:

       _
 _____|_|_____
|             |
| 6 5 x 3 2 1 |
|_____________|

1 - Trigger (Base) 1
2 - Trigger (Base) 2
3 - Ground (Emitters)
5 - Output (Collector) 2
6 - Output (Collector) 1

So you could connect the triggers to both ignitors, provide both ignitors with a good solid engine ground, and connect each ignitor's output to one coil.

[heelhooker]

Thanks for the pinout.

Interesting, right after I posted, I started thinking about trying to use two igniters too. Is this the type of arrangment you were thinking?



I'm going to see if I can get a couple of igniters at the junkyard tomorrow. Hopefully I can get the male connector off of one so I don't have to hack up my bulkhead harness.

[vrg3]

Hehe, wow, I never in my life expected to see a 3D rendering of two ignitors connected to four cylinders.

Yes, that's what I had in mind.

[heelhooker]

haha I guess it's kind of overkill. Actually, it was faster for me to use solidworks than it would have been to draw it some other way.

Igniters must be a hot commodity. Every legacy I saw at the jy had it stripped off already.

I ended up stretching on my old plug wires and coil, and the car started and ran really smooth. I'm just going to get some proper wires and do it that way.

[vrg3]

Cool, yeah, that's probably the best way to go.

You might want to look on the RS Liberty forums to see what kinds of wires they use when they convert to coils-with-leads. When the stock coils die off they like to replace them with Bosch coils and plug wires. You could then Frankenstein those wires with the stock wires.

[BAC5.2]

Why do they like to do that and ditch the coil-on-plug setup? Expensive to replace?

[vrg3]

My understanding is that the stock coils are somewhat prone to failure, in addition to being expensive to replace. A high-energy coil meant for a distributor seems like a natural alternative.

[keelhaul]

hey.

i'm thinking of getting a new set of coil packs for my ej20g. is there other subi engines i can pick this from, or must it be an old ej turbo engine? someone told me subaru norway takes 260$ per coil...
im sorry if this is unclear, as im not sure how the device is actually constructed, hehe