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Old 10-17-2012, 01:25 PM   #1
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Default Definitive lsx coil guide?

Okay guys, I've been having a spark issue that's intermittent. Typically its high RPM's, and only after about 10-11 psi of boost - and does so more on colder nights. Typically it breaks up for a fraction of a second and pulls right through, and I believe this is spark blowout. My afr/s are safe, and the timing map is pretty standard (got it from the brain).

Now I've been researching COPS for a while here, but after reading as much as possible it sounds like I could go for the lsx coils for about the same price (looking at ls2 truck coils, they seem to be the hotter ones available for cheap), and then have more headroom for a built motor, or whatever.

Basically this is what I've gathered. You wire these in the same as a COP conversion.

This is the pinout for a ls2 truck coil:


You set dwell settings to 5.0-5.5 ms dwell for LS2 coils

This is where I get confused. The COPS have a tach signal on their pinout, the lsx coils dont. I'm running an OG MSPNP (ms1) which apparently does not have a built-in tach output. This is what concerns me. Looking into this it appears there is no way to get a tach signal without opening up my ECU and adding a circuit, which i'd rather not do. This is what cockblocks me.

My main question here is this, is there any easy way to run these using an og MSPNP(MS1) on my 90-93 car? I figure i could install them fine via the various diagrams available, run the above dwell settings, run batch (wasted) spark like i currently do without having to modify my ecu, but then where I see a problem is from the tach signal.

Anyways flame on if you want, I do like to think I've done a fair amount of research at this point and I'm just stumped. I read through 10+ threads all day yesterday at work and have only ended up more confused due to the different variables in the years of miata(94+ uses the ecu for tach output?), different ECU types, and finally different firmware types on top of that.

ALSO, if there is a "definitive lsx coil guide" or any write-ups on this please point me that way. I found tons of various threads with info scattered around, but no "lsx coil write-up" like there is for COPS.
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Old 10-17-2012, 01:43 PM   #2
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I think you are going about fixing the problem the wrong way.

I would start with your plugs.

Buy a fresh set, and gap them a bit tighter than what you have now.
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Old 10-17-2012, 02:02 PM   #3
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Thanks for the insight fae, you may absolutely be right. The plugs were gapped down already and the problem had been resolved at that time. However once again this started happening again, this time at even lower boost levels. I had assumed my 160k oem coilpack wasn't supplying the juice i need. New properly gapped plugs will be the first thing I'll try.

However I've got a 99 BP sitting in my garage that I'm building a new turbo kit around for this winters project, so upgrading my coils is certainly still going to happen. Now I'm stuck deciding between lsx coils and COPS, it looks like i'll go with COPS if there's no easy solution for tach output on these lsx coils for my car.
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Old 10-17-2012, 02:12 PM   #4
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Quote:
Originally Posted by Faeflora View Post
I think you are going about fixing the problem the wrong way.

I would start with your plugs.

Buy a fresh set, and gap them a bit tighter than what you have now.
no I think he's doing the right way. stock ignition is gay and aids. for $200 he can have a set of LS truck coils running.

You can mod the MSPNP to output a tach signal
https://www.miataturbo.net/mspnp-55/...-output-64082/

You need 4 coils, 4 pigtails and 4 wires.

For wires I use MSD Ignition 32829 (they come in pack of 8)
Amazon Amazon

For coils I used D585 coils. I bought 8 of them off ebay with wiring harness and bracket - the exact item
GM GEN III 5.3 6.0 LQ4 LQ9 LSX D585 IGNITION COILS W/BRACKETS AND WIRE HARNESS | eBay

The coils appear to have gone up in price considerably.

For bracket I used a sheet of 22 gauge steel from Home depot and bent it/raped with dremel. You can find pictures in my build thread.
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Old 10-17-2012, 02:32 PM   #5
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Old 10-17-2012, 02:37 PM   #6
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Quote:
Originally Posted by soviet View Post
You can mod the MSPNP to output a tach signal
https://www.miataturbo.net/mspnp-55/...-output-64082/
Has this been verified to work at this point? Every thread i see that output mentioned in, it's followed by "you can try it, but I'm not sure if it will work".

Also, am I a ***** for not wanting to crack open my MSPNP and add a circuit? I'm decent at soldering, but that still scares me LOL.

And I've seen your coil setup Soviet, looks badass. Thanks much for the links here, gives me more to think about.
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Old 10-17-2012, 03:02 PM   #7
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yes that makes you a *****.

you could probably use something gay like this - New! Tachometers Replacement Inductive Pickup Fast Free Shipping! | eBay

combined with a 12v pullup and wasted cop (or wasted spark) mode

edit: actually this still wouldn't work because tach expects 1:1 signal (i think)
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Old 10-17-2012, 03:13 PM   #8
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Hmm, nah that looks too ghetto for my tastes. Thanks for the link though. Now I know what needs to be done at least. Thanks for all the clarification.

Now onto deciding if I want to mod my MSPNP for tach output or not. Now I understand why COPS were/are so popular. My eventual goal is somewhere around 300whp, but on the stock motor I wont go over 250whp or so. Cops should support this, but something about me wants to go for the LSX coils still because they are so much better.
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Old 10-17-2012, 03:39 PM   #9
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it should be extremely easy to mod the MSPNP. I've never seen one but as I understand it has a daughter board for the stock ECU connector inside. If so, all you gotta do is find the "2X" pin on the harness connector and solder a jumper to an output of your choice (I forget what I used - but like JS1 or whatever). And add a pullup resistor.
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Old 10-17-2012, 04:33 PM   #10
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If you go with the normal LS2 coils you can get the bracket and spark plug wires from FM for about $150 shipped. Then buy the coils and pigtails off ebay for cheap.

I would say spending the few extra dollars on the LS2 coils is worth it over going with cops. I have had problems with cops in the cold and at higher boost levels.
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Old 10-17-2012, 06:04 PM   #11
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If you get LS2 coils and the FM bracket order a dozen or 1/2 dozen of the little aluminum spacers they use on the bracket. My LS2 coils needed a hair more spacing apart to not rub each other. Also I need to flip or bend one brackets tab 180deg to line up the holes again. Seriously it's 5min work tops over fabing you'r own bracket.
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Old 10-17-2012, 06:43 PM   #12
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Quote:
Originally Posted by shuiend View Post
If you go with the normal LS2 coils you can get the bracket and spark plug wires from FM for about $150 shipped. Then buy the coils and pigtails off ebay for cheap.

I would say spending the few extra dollars on the LS2 coils is worth it over going with cops. I have had problems with cops in the cold and at higher boost levels.
I'd agree with this. Price point wise, lsx coils are for the win. I understand wiring enough to wire up these coils, so that's fine as well.

The problem with mine is the fact i have no spark output and have to modify my ECU. In order to do that I have to make sense out of this diagram



And I'm ashamed to admit it doesn't make much sense to me yet.

I do believe I found the 2n2222a collector i need
2N2222A STMicroelectronics | 497-2598-ND | DigiKey

I'm sure i can find the diodes and resistors too. I don't understand the "pin 31 or 36 from db37" but I'm assuming that's off the MS board. I'll have to look up a pinout for my mspnp to find those, but that seems do-able.

I'm not sure what the upside down triangle thing (Ground ??), made of parallel lines is that is coming off the "emitter". And i assume the +12v can be sourced from any switched power source?

I want to do this, but some of this i dont quite understand yet. I'm going to continue researching all this to see if I can pull it off. If not, I Might have to go with dem cops.
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Old 10-17-2012, 07:11 PM   #13
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Quote:
Originally Posted by Fireindc View Post
I'd agree with this. Price point wise, lsx coils are for the win. I understand wiring enough to wire up these coils, so that's fine as well.

The problem with mine is the fact i have no spark output and have to modify my ECU. In order to do that I have to make sense out of this diagram



And I'm ashamed to admit it doesn't make much sense to me yet.

I do believe I found the 2n2222a collector i need
2N2222A STMicroelectronics | 497-2598-ND | DigiKey

I'm sure i can find the diodes and resistors too. I don't understand the "pin 31 or 36 from db37" but I'm assuming that's off the MS board. I'll have to look up a pinout for my mspnp to find those, but that seems do-able.

I'm not sure what the upside down triangle thing (Ground ??), made of parallel lines is that is coming off the "emitter". And i assume the +12v can be sourced from any switched power source?

I want to do this, but some of this i dont quite understand yet. I'm going to continue researching all this to see if I can pull it off. If not, I Might have to go with dem cops.
I did run this circuit in my car for a little while and it did work, but ended up going back to cops. Yes the upside down triangle is ground and +12v refers to any switched 12 volt source.
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Old 10-17-2012, 07:15 PM   #14
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Quote:
Originally Posted by hochkis View Post
I did run this circuit in my car for a little while and it did work, but ended up going back to cops. Yes the upside down triangle is ground and +12v refers to any switched 12 volt source.
Interesting. Good to know the circuit works, why did you go back to COPS?

I'm still considering going with the cops due to ease of installation and how damn clean they look. However massive spark is very appealing as well since I'm planning on running e85 with my new setup.
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Old 10-17-2012, 08:05 PM   #15
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Quote:
Originally Posted by Fireindc View Post
Interesting. Good to know the circuit works, why did you go back to COPS?

I'm still considering going with the cops due to ease of installation and how damn clean they look. However massive spark is very appealing as well since I'm planning on running e85 with my new setup.
Mostly because I'm lazy and they worked, got tired of mucking around with mounting and running spark plug wires. I'm only at about 200whp.
I was running the Diyautotune ign-4 and not LSx coils.
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Old 01-01-2014, 05:50 PM   #16
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To bring this back from the dead, is the diagram only for MSPNP or is it for MS2PNP?
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