Coil on Plugs (Ben91)

[Mazdababy]

I've been reading up alot on COP (Coil on plug) for our cars. I know which ignition coils to get, but is it necessary to get a dwell reducer for my 1.6l (stock ECU)?

http://www.boundaryengineering.com/dwellreducers.php

I was reading a thread on Miata.net you posted in
http://forum.miata.net/vb/showthread.php?t=263446&page=1
it's pretty advanced and hard to follow :confused: I understand all the wiring, and I have a diagram I got off of CR.net.

So far the plan is to get the 4 ignition coils, gut the ignitor, and run all the wiring.
The question is, do I need to buy the $50 dwell reducer?

http://www.boostedmiata.com/FAQ/cops/1.6L_COP_Schematic.jpg

[ben91]

If you do not have proper dwell control, the coils will be forced into current limiting for every ignition event. This will result in premature coil failure. You'll need the dwell reducer and you'll need a pullup between +12V and tach.

The Toyota coils really aren't all that hot. I'd go with LS2 truck coils or IGN-1A (http://www.diyautotune.com/catalog/ign1a-race-coil-p-394.html) coils, but then you'd need a tach driver too.

Aftermarket engine management would be much more flexible.

(http://www.diyautotune.com/catalog/ign1a-race-coil-p-394.html)

[Mazdababy]

In the diagram, where does the dwell reducer come in? I've read the entire tutorial on MT and there is nothing about dwell reducers (make sense since it is a turbo site; no stock ecu).

What do you mean by a pullup between the +12v and the tach?

[ben91]

There's an installation manual on the page you linked me to.

A pullup is just a resistor.

[Reverend Greg]

http://www.mx5atlanta.com/forums/picture.php?albumid=19&pictureid=548
Ben What about these? they are cheap and Pretty hot.Summit racing coil for~ $30
(G)

[ben91]

Don't know anything about them. What will you use for an ignitor?

[Reverend Greg]

Thats what I thought,I do not have the ability to build such,so....I like the LS6 coils that you are running,I just need to find a source for inexpensive coils.I do not want to spend more for the ignition than I spent on the rest of the turbo system.
(G)

[ben91]

What do you have for engine management?

[Reverend Greg]

I "will"be Running a PNP 'squirt.550 cc injectors,190 fuel pump,2 feed fuel rail...so you see,Ive got a fairly common system..fuel wise..Now I just need to shore up the spark side.My avatar is my turbo Map ...Garret t-25,Equal length,equal volume tube manifold,looking into EWG.4th order Tuned resonance custom intake manifold(by me),want to push 10-15 lbs of boost.I might not need an ignition,but at the top end of the flow for my snail,the mixture may be hard to get propigated...sooooo.Thanks for all that you do for the forum...you are the man Ben!:banana:
(G)

[ben91]

The white box MSPNP? I don't think I could recommend installing ignition drivers in one, so your best bet would be to find coils with built in ignitors. LS2 truck coil packs will work, but without sequential ignition won't be able to charge fully beyond 4500 rpm. We had to back mine down from 5.5 ms dwell to 4.0 ms to give them recovery time between events, which limits their output.

These guys will work well in batch or sequential because their dwell time is half of the LSx coils. They're also more powerful. I'm going to them.
http://www.diyautotune.com/catalog/ign1a-race-coil-p-394.html

[Reverend Greg]

I still ahve the Problem of those coils costing more than Ive spent for the Turbo,Intercooler,BOV,intake&exhaustmanifolds,Coolant reroute,fanshroud,injectors....I think you get the Picture.I take it that the way to go is to have A Mega-squirt built that contains the ignition drivers,I really like the Idea of going to the Junkyard to get The coils off of a truck...will be inexpensive.To the OP Iam sorry for the Thread jacking...Ben is just a smart guy...he Is to electricty,what I am To steel.
(G)

[ben91]

A Ford EDIS coil would do pretty well for you if you really want to run on a shoestring budget. They don't have internal ignition modules, but they're cheap, fairly hot, and have a short dwell requirement. There's an application list on this page: http://www.megamanual.com/ms2/EDIS.htm
Get the coils off of a 4 or 8 cyl (the 8 cyl has (2) 4 cyl coil packs). Should be easy to find in a junkyard, or cheap to pick up aftermarket.

Don't worry about anything else that page talks about, other than the EDIS application list. You can directly drive those coils off the MS ECU if you add (2) ignition modules. We won't require the rest of the EDIS hardware or trigger wheel.

[Reverend Greg]

You da man!
(G)

[Mazdababy]

To the OP Iam sorry for the Thread jacking...Ben is just a smart guy...he Is to electricty,what I am To steel.
(G)

No problem man, my question's been answered.

[Dynra Rockets]

FWIW I used a MSD DIS-2 in my car and I love it. Starts much better and substantial torque increase below 3000 rpm.

Picked up used one on ebay for about $100.

There are several writeups on Miataforum (iirc Rob has a diagram on his site too) on how to install but basically you use 90-93 coils without the integrated ignitor, cut the wires that go from the ignitor (or ECU in a 94+) to the coil and insert the MSD in between and then run a separate 12v power to the coils.

[ben91]

Sure the ignitor in the NA6 is on the weak side.
Keep in mind though that the NA8 and beyond don't have external ignition modules.

[Matt Cramer]

Another possibility is to swap over a DSM coil pack and ignitor. Same 5 volt logic level output, a bit hotter spark.

[Dynra Rockets]

Sure the ignitor in the NA6 is on the weak side.
Keep in mind though that the NA8 and beyond don't have external ignition modules.

Agreed. For a 1.6 application the ignitor is just used to trigger the MSD. For a 1.8 application the trigger comes from the ECU (but must use the 1.6 or alternative coils without a built-in ignitor).

The MSD is very tollerant to the signal it gets for a trigger and will accept almost anything.