My way to prevent Lazzer from deleting this thread.

 

Anyone running cop? (coil over plug) What coils did you use and is it in a turbo application? What boost levels? I found some from a 2000 something Corolla. I plan on welding and taping standoffs to the valve cover to bolt the coils to. They fit the plugs and valve cover quite well. From what I can tell they have ignitors in them. Does the tach pulse come from the coils? If so I'll have to figure out if 2 diodes off of #1 and #3 (or #2 and #4) would run the tach.

 

Yeah, I believe J_Man on www.miataforum.com does this.

 

Yeah I know a few are doing COP w/AEM. I looked into it for a little while. Mostly with 300C coils I believe. there's also some info on aem's forum.

 

The ignition system of a 1.6 Miata appears to be a clone of a DSM- igniter, coils and all. You'd be hard pressed to find an OEM coil that is more powerful.

 

GM HEI...

I have read the Miata coils (1.6 and 1.8) have issues missfiring when your over 15psi of boost. aka not enough voltage/current

 

With Megasquirt you can easily run HEI.. Or MSnSE I believe has ability to do 4 ignition coils. I was going to try it, but didn't want to hassle with the extra work. If I end up having troubles when I start for my power goals I'll switch. However I come from the land of turbocharged ford 2.3 liters and the first rule with those was don't mess with the ignition system. The factory TFI on 2.3s was prone to failure when they aged but produced more than plentiful spark for 30+psi drag motors. All the guys I saw with serious ignition problems bought aftermarket coils and igniters.

On a Miata, ignition is one thing I don't have any experience with so I can't say for sure.. just offering up my $0.02.

 

Well this is easier then I thought. I have coil over plug working wonderfully. My idle is smoother and all around response is much better. These coils I'm using go for as little as $5 +$6 shipping used on ebay. I paid $38 shipped for my set. Can't beat that deal. I found the connectors at the junkyard this afternoon. I'm running them paired right now with 1+4 firing together and 2+3 firing together, much like the stock wasted spark setup. This means the stock ECU is quite capable of running with these coils. It will eliminate the plug wires and in my EMS I'm showing less noise on the other sensors (tps and map). I'll run them sequential as soon as I get the other connector for the EMS that I need for the other 2 coil outputs. If anyone is seriously interested in doing the same thing I can give you color-to-color wiring explanations of how it's done. PM me.
Here's a few pics. Sorry for the poor quality. I dropped my camera.

 

good stuff! nice pics aw well

 

I want that info. I have crazy noise in my water temp sensor. I'll PM you.

Oh, and how is the tach working?

 

The tack works fine. These coils have a tach output. When running them paired like this I used just 2 of the coils tach outputs. When I wire them sequential I will tie all 4 together.

Tim your running the EMS arn't you? I talked to Henry at AEM and he sort of walked me thru the sequential setup. It's pretty much just enabling 3&4 and changing the tooth setup for when they fire.

 

I know how to do it within the EMS software, and I know how to wire the coils on the EMS end. I just don't know what the wiring is like on the coil end. I'm looking for information like: "I'm using ~2000 Corolla coils. They have 4-wire connectors on them. The wires are for 1. Ignitor signal from ECU, 2. +12VDC, 3. Tach, 4....."

 

Not to side track the thread but I am wondering if the Miata coils and DSM coils are actually the same then. They are externally, and they can interchange, so if the DSM coils are actually better this might be a nice upgrade. They still spark at 35psi and 8500rpms, which is pretty good for OEM.

More on topic:
LS1s, 90s Camry V6, 2000+ Celicas all have COPs with igniter on coil. Could be good sources for those of you with standalones.

You can wire various other coils without an igniter (some motorcycle coils and 300m for instance) for COP with the stock system but I still question whether they'd work better than stock. They aren't designed to work in wastespark with half the charge time.

 

Turbotim, The coils are from most 2000+ Toyota's. Mine are from a 2003 Corolla. Looking at the plug on the coil, with the sparkplug end facing down, the pins are...
From left to right.
1 - Ground
2 - Trigger (fires on falling edge)
3 - Tach output
4 - V+
If your firing them 2 at a time, use one tach output from each pair and hook them together to the miata's tach input. The miata's coil's have the 2 tach inputs connected in the harness. For example. Use cylinder #1 and #2 tach outputs from the COPs. Just incase there are differences between years, test the coils on the bench first. I did that anyway to make sure all the coils functioned before I installed them.
I would imagine that the plug temps could be lower since there firing 1/2 as often when ran sequential. Maybe the'll last twice as long too. I haven't burned thru a tank of gas yet but I was at 75mi when the needle was lined up at 3/4 full and now I'm at 92mi with a needle width to go before it's on 3/4 full. Apperently I'm getting better mileage. I was at 22/28mpg average.

 

Thanks.

If I do this, I'd definitely run them sequentially, not batch like OEM. Did you have to change the dwell settings at all?

 

Yes. Use the wizard and choose the toyota tc etc etc coils. It's the last one on the list in mine. Dwell vs. RPM is flat by default in mine. Normally the Dwell is shortened when rpm rises?

 

More pics....

I welded on some threaded studs for the coils to be bolted down to. This is an extra valve cover I had laying around. Freshly painted. I just need to sand down the letters.

 

now you said that the stock ecu is capable of running these coils, do the COPs already have igniters in them, and any idea on how you figured out the wiring, and if that can be adapted to an nb?

 

It can be adapted to about any car. Yes, the coils have ignitors in them. If you look at the pinout for the miata coils they have 4 wires as well. Power, Ground, Trigger and tach. If I remember... the trigger for 1&4 is a brown wire and 2&3 is brown with a stripe. To use the cop coils you have to tie there trigger wires together for the 1&4 coils and hook them to the 1&4 trigger from the stock ecu. The same goes for 2&3. Then use the tach outputs from one cop coil from each pair of cylinders and tie them together. This fires two of the cop coils at once so it's still wasted spark. I tried it this way at first untill I had time to tear into my engine bay harness and repin some of the wiring to do sequential. It ran better using cop then the oem coils. If I have time I'll make a write-up on how to wire the stock ecu for cop ignition.

 

sounds like there is enough info here, to start looking into doing it myself thats awesome. genius