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-   DIY Turbo Discussion (https://www.miataturbo.net/diy-turbo-discussion-14/)
-   -   COP Thread (https://www.miataturbo.net/diy-turbo-discussion-14/cop-thread-4756/)

Saml01 02-20-2008 11:08 AM

^ you mean the one all the way in the back to the left if looking at your picture?

I too wonder what that plug is, maybe it has the triggers?

orion4096 02-20-2008 11:26 AM

Yup, the one sitting all the one in back right next to the ignition coil pack standing straight up. If you believe the color coding it has exactly what we need:

gnd - black
12v - white/black
tr14 - brn/ylw
tr23 - brn

In the wiring diagrams it looks like the white/black wire feeds the main relay's coil, but nothing else. I guess it's a pretty easy test if the main relay still works after unplugging the connector. My setup used the connectors off the coil packs with the resin removed, but it's hard to get my hands back there to unplug those connectors. It would be nice getting one of those connectors...

Saml01 02-20-2008 12:01 PM

I wonder then why everyone who has that plug there didnt use it for the coils. Certainly easier to cut there then at the coils.

edit: I looked at the madracki diagrams, they didnt show much but that could be the place where the +12v splits for the main relay and engine fuse. I guess as long as you cut after it, then it can be useable. I could be wrong.

Saml01 02-20-2008 08:20 PM

Hey Scott, did you get my PM?

slomx5 02-20-2008 08:39 PM

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

thebeerbaron 02-21-2008 11:08 PM

Is anyone using high-temp rated wire like TXL/GXL for these? If so, where did you source your wire?

And what's the consensus on wire gauge? If so, how did you arrive at that number?

Saml01 02-21-2008 11:28 PM

Just use whatever the ignition coils have running to them. Probably 18 gauge will be plenty. At least thats what im gonna be using, I dont want to go buy another 4 spools of wire for like 2 feet worth of wiring.

lazzer408 02-22-2008 12:17 AM


Originally Posted by thebeerbaron (Post 217857)
what's the consensus on wire gauge? If so, how did you arrive at that number?

A larger wire is always recomended when you want to keep the voltage drop to a minimum. ~1.36v loss on the primary is ~4500v loss on the secondary.


Originally Posted by Saml01 (Post 217877)
Just use whatever the ignition coils have running to them. Probably 18 gauge will be plenty. At least thats what im gonna be using, I dont want to go buy another 4 spools of wire for like 2 feet worth of wiring.

Don't use #18 for power or ground for all 4 coils. I'd buy 4 spools of wire before I risk setting my car's wiring harness on fire. If it's just a 12" run of #18 from the coils to meet up with a #12 that's ok.

#18 is fine for triggers.

cjernigan 02-22-2008 12:29 AM


Originally Posted by Saml01 (Post 217877)
Just use whatever the ignition coils have running to them. Probably 18 gauge will be plenty. At least thats what im gonna be using, I dont want to go buy another 4 spools of wire for like 2 feet worth of wiring.

If you're really worried about not buying larger wire, use two strands of 18 awg in parallel fashion to act as larger wire. It should still fit in crimp pins just fine.

Zabac 02-22-2008 10:24 AM

if you know any electricians just score some wire from them, they are usually pretty cool guys
my brother in-law gives me the hook ups, pretty much and kind of wire i want FREE
but i used 12ga for power/ground and 16ga i believe for trigger/tach

thebeerbaron 02-22-2008 11:15 AM

Ok, I'll look for some 12ga, that's about what I calculated I'd need to carry the current with minimum drop, it just seemed like others were going with smaller.

Is there any worry about heat on top of the motor? I see some of you running split-loom and I'm amazed that hasn't melted. Maybe I'm just a fanatic, but if I had easy access to TXL/GXL, I'd be running that.

AbeFM 02-22-2008 12:33 PM

12 ga? The wire feeding the coil stock is 1/10th the size. Seems like a lot of overkill. Very much the same concept as putting a 6.5" downpipe on your turbo, feeding a 2.25" exhaust. Not to mention it's like doing it on a 150 hp car.

I'd shoot for something in the ballpark of the same size Toyota used. No smaller, but around there.

Braineack 02-22-2008 12:39 PM

20awg on tach, 12v, ground and trigger ftw!

Zabac 02-22-2008 02:23 PM

rather safe than sorry eh!
FWIW, my brother in-law (licensed electrician) recommended 12ga on power and Ground only...just to be safe

jayc72 02-22-2008 02:33 PM

12ga is fucking huge for this application. I used 14ga and it was stupid big, but it's what I had on hand. 16ga or 18ga would suffice I'm sure.

AbeFM 02-22-2008 03:06 PM

Really, toyota runs them off VERY small wires. They wouldn't spend the kind of money it takes to develop a COP system with warranties and all the rest, then use wires like that.

12 guage wire is rated for 41 amps.
FOURTY ONE AMPS. Are you kidding? 1 milliohm per foot.


20 guage is rated for 11 amps, and it would take 1000 feet of it to total only ten ohms of resistance. And that's 11 amps continuous.

Do what you will, but I stick by my advice. Use what toyota used.

http://abefm.smugmug.com/photos/252079866_uzPMX-XL.jpg

See the wires coming out of the coil? They are PUNY. See the giant ground strap I have? It's 16 guage, and the toyota wires would fit inside of the insulation of that with room to spare. Spend your time/money/etc on heat sheilding.

Saml01 02-22-2008 03:17 PM


Originally Posted by AbeFM (Post 218091)
12 ga? The wire feeding the coil stock is 1/10th the size. Seems like a lot of overkill. Very much the same concept as putting a 6.5" downpipe on your turbo, feeding a 2.25" exhaust. Not to mention it's like doing it on a 150 hp car.

I'd shoot for something in the ballpark of the same size Toyota used. No smaller, but around there.

THANK YOU

Saml01 02-22-2008 03:18 PM


Originally Posted by whaaamx5 (Post 218150)
rather safe than sorry eh!
FWIW, my brother in-law (licensed electrician) recommended 12ga on power and Ground only...just to be safe

But if whats running in the car is less then what you plan to run for that 12 inches, what difference will it make? Imagine it like feeding a firehose with a straw.

M-Tuned 02-22-2008 03:20 PM

Think I might start my wiring harness for my COPs this weekend. Lets see how much spare time I have...

thebeerbaron 02-22-2008 03:24 PM

ok, my confusion has been in the AWG table, whether this is considered power transmission or chassis wiring. i'm not an EE, I don't know the difference.

i finally got time to pull the coils. damn those things are packed back in there. yeah, the OE wiring is really tiny.

I think I have enough 18awg lying around to do it.

Thanks all.


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