Since I've run out of juice in the Fab9 COP kit and don't want the issues with heatsoaking the driver for it, I have decided to go to D585 GM coils. I do have a few questions, all kind of tied together.

1. Brackets: Make one or buy one, I am not finding anything out there readily available. I do like how compact the FM Big Spark kit is, and the firewall mounting location, but cannot find the mounts alone. Most that I've seen custom made have been a hit or miss, function is important but I do want a clean appearance to be in line with the rest of the build.

2. Wiring: Where I mount the coils also dictates how long the wires from the spark plug to the pack will be. Is a 3" wire really more effective than a 9" wire? I'm comparing say mounting them near the valve cover/intake manifold vs mounting on the firewall. I know short wiring is where it's at, but 9" or whatever it is from firewall to the cylinders is still short IMO.

I have a harness lined up, I am getting OEM D585 coil packs, but depending on the answer to question 2, question 1 may have to adjust. Below is a photo of my engine bay. The silver bracket behind the exhaust side of the valve cover is where the Fab9 module lives. I'm thinking of that firewall area to be the home for the GM coils, but wanna see what others have.

 

If you call them you can get the mount alone.

 

Might try that actually if I do that location. I know they will sell the wires separately, but judging by the price of the kit, I don't imagine any parts of it are inexpensive.

 

I think I paid $45 for the FM mounting hardware, the part number for the kit was 26-04320.

I bought the crimped pigtails from Ballenger Motorsports.

 

Does it fit the coil packs that have the heat sinks on them? I can't tell from the photo but I hear FM uses different coils as well.

So if I did that, I would basically buy the wires from FM as well, since they would already be the correct length, unless someone can measure theirs and see if I can get them made for less. I don't have a price on the wires from them either.

 

You need to read this thread: https://www.miataturbo.net/diy-turbo...-thread-82744/

D585 coils wont fit the FM brackets (too wide and tabs in the wrong spot) and you wont fit them between the firewall and engine on the MSM - I know, I tried but there's not enough room behind there since the D585 coils take up a lot of space and their mounting tabs make them even harder to fit than the other LSx CNPs (most LSx coil mounting tabs are on the front and rear of the CNP, the D585s are on the top and bottom, making them "taller" than the other LSx coils).

Here's my D514A CNP solution, similar to the Singular mounts but with the CNPs mounted upside down from theirs to maximise clearance between the hood and CNPs.




Custom D514A CNP bracket for MSM

 

Are those D514A coils potent enough to support my power levels? I like that setup, it looks pretty clean!

I assume the harness for these is also different correct?

Just found this: https://www.flyinmiata.com/big-spark-kit-no-coils.html

A bit expensive, but it's a clean install, and everything I need but the coils themselves. That's the problem, the coils seem to be $65 a piece and I need 4. The price of just the hardware kit from FM is more than a D585 setup costs, so I have to decide if I want to deal with longer wires and a more remote mounted COP bracket, or pony up. That is, if this even fits behind the head with the M-Tuned reroute I have.

 

Double post, but just need to confirm that the big spark kits out back with the m-tuned re-route. I'll be using the D510C coils that FM does for their kit. Not the most powerful, but certainly more than enough for what I have.

 

Did you build your own plug wires?

 

Sort of, for details, see post #82 in https://www.miataturbo.net/diy-turbo...-thread-82744/

I bought the FM Big Spark Kit Magnecor wires but they were WAYYY too long so I had to shorten them.

BEFORE:

FM Big Spark Kit Magnecor wires - WAYYY too long!

AFTER:

Shortened leads - much tidier!