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Ls2 Coil On Plug Mod


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On 12/30/2016 at 6:39 AM, WMDC35 said:

Have you got a good earth/ground?


It's currently earthed to the fuel rail, not the chassis body. 

On 12/30/2016 at 3:47 PM, MrStabby said:

Yep, and check that you have the full ~14.5V (alternator charging) at the coils when you're hitting boost. IIRC another SAU'er had an alternator who's output was trailing off higher in the RPM band, so you'll want to log it, even if only at the ECU (cause logging at the coils probably wont be so easy).


I will need to check it properly. Before the engine went back in, I had an auto elec test the alternator and he said it was working as it should (no other details though). 

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On 9/22/2014 at 0:56 PM, BlueRB240 said:

I'm thinking about cutting up some copper tube and shaping the ends instead of using these - would it be ok?

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So alternator is rock solid. Added an extra 10% dwell through the rev range, has helped a lot, one tiny hiccup coming onto boost and then no problem after that. I do believe the factory springs and boots are the issue though. What else has everyone done to mount the LS2 coil packs directly onto the spark plug? I saw someone tried these terminals but not sure how they crimp onto the end of the coil pack.

New-set-of-10-MSD-34605-dual-band-spark-plug-terminals

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AFAIK: The rolled up end will be for connecting to the plug, so about 6.3mm ID. For the other end, crimp it down enough so it grips on the coil terminal a bit. If your coilpacks are D514a's or similar, then the connector will be "captured" by the plug and the coil terminal when its assembled, so wont be able to move.

If the boots are problem (insulation problem), then there will be arcing from the coilpack to the head. Sometimes putting a little dielectric grease the surfaces where the boot touches the coilpack and head can help with that. If the boots ripped you'll have to get another.

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3 hours ago, MrStabby said:

AFAIK: The rolled up end will be for connecting to the plug, so about 6.3mm ID. For the other end, crimp it down enough so it grips on the coil terminal a bit. If your coilpacks are D514a's or similar, then the connector will be "captured" by the plug and the coil terminal when its assembled, so wont be able to move.

If the boots are problem (insulation problem), then there will be arcing from the coilpack to the head. Sometimes putting a little dielectric grease the surfaces where the boot touches the coilpack and head can help with that. If the boots ripped you'll have to get another.



Yep exactly what I was thinking cheers, just yet to see the connectors in person and make a fair judgement. I'm using the LS2 coil packs, although they are the BS1251 part number, which one person in this thread has said they're the inferior made genuine ones. I upped the dwell by about 10% and that has made about 90% of the misfire go away for now, with maybe one hiccup as it hits boost. More investigation required! 

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EDIT: The 6 pin plug is 1 -> 6, not 6 -> 1. Working now

 

Ok i've got mine installed and wiring in, but no worky. Here's how 6, 5, 4 coilpacks are wired - does it look correct? The 3 and 6 pin connectors show facing the factory plugs, and the others are facing the coils.

AFAIK the +12V comes up when IGN is on, and the signal from the ECU is +5V when the ignitor should disconnect ground to the primary solenoid, right?

ls-rb-coil-wiring.jpg

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  • 1 month later...

Update: So to touch on this, I ended up having an intermittent coil pack!! And it just so happened to be the coil over cylinder 6, it may have been the heat, or may have just been unlucky as there shouldn't be ENOUGH heat to kill it back there.

PAT offers a 2 year warranty so I replaced it today and misfire completely gone through the entire rev range. 

Currently running an 0.7mm gap with some MSD 34605 terminals which have been lightly crimped at the coilpack end (enough that they'll clip over the coil pack end), and then this is covered by the factory rubber boots found on RB Coil packs. I use a WiringSpecialties coil pack loom which is a custom loom for LQ9 to R33 GTR. 


This is what the terminal looks like.
Image result for MSD straight spark plug terminals


 

IMG_4390.JPG

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16 hours ago, Borci88 said:


Currently running an 0.7mm gap with some MSD 34605 terminals which have been lightly crimped at the coilpack end (enough that they'll clip over the coil pack end), a

 

Are you happy with how the terminals sit? I'm just using the springs from the factory coils with a bit of stretching and reshaping, but haven't had a chance to do full boost testing to verify it under stress.

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5 hours ago, MrStabby said:

Are you happy with how the terminals sit? I'm just using the springs from the factory coils with a bit of stretching and reshaping, but haven't had a chance to do full boost testing to verify it under stress.

Yep, I'm more confident with them than the springs, I was just waiting for the springs to burn out or something like that. Unfortunately my brackets dont suit the extra height that the terminals create, but.. it all works and is sealed! I will be dynoing it in the next month or so and aim for over 400 without touching the gap or dwell anymore.. in fact kind of plan on lowering the dwell from the 3.7ms that it's at roughly at the moment.

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