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One key thing to understand is the logic level inputs are sensitive to noise.
The power ground by virtue of it high current level is likely to create noise
The spark return by virtue of its high voltage output is likely to create noise.
By keeping the grounds separate, you minimize the likelihood of interference.
The Adaptronic article was more for that particular individual's self inflicted problem with a ground loop, though it does help explain the concept of loop area. I wanted you to see Chris Ludwig's advice, and how it has evolved over the years as communities got more experience with these coils. Again, he is the "expert" on these coils in these cars.
The generally accepted method, which all the professionally built harnesses for these cars choose to do, is to connect the logic/sensor ground to the same location you ground the secondary return (which is segregated by front and rear rotor). This is not "correct" as I explained in the linked thread, but the reason you can get away with this is because this ground is for the logic trigger of the coil, which has tolerance on the logic levels by design. The correct way would be to connect all four logic grounds to sensor ground on the vehicle harness (same ground for TPS and any other sensor with a dedicated ground back to the ECU), but virtually no one does this and it seems to be OK. As I explained in the other thread, the whole purpose of using sensor ground is so that the logic threshold does not unintentionally shift due to ground offsets caused by high currents in the power grounds. Any ground on the engine WILL experience an offset, as the Adaptronic article helps explain.
The secondary ground is more critical because it is the return path for the spark; this ground directly impacts the spark performance of the coil. The whole reason you have upgraded to these coils is the improve spark performance...which is why it makes no sense to increase the loop area and rely on the sandwiching of the irons and plates to make the return path of the entire keg "look" the same, which it's not when talking about a high energy pulse signal like spark.
Sent you a PM Daniel. Had a few questions regarding the grounds and the different systems I see for sale.
I can’t find my original install instructions for the SakeBomb kit. My harness appears to be different from what is currently in the kit. My harness looks like the one they sell with the RHD kit. There is a small black wire with a ring terminal coming off the adapter harness, I have it tied into the harness that goes to the map sensor for some reason. Does anyone have a copy of the original install, or know what this wire is for?
I can’t find my original install instructions for the SakeBomb kit. My harness appears to be different from what is currently in the kit. My harness looks like the one they sell with the RHD kit. There is a small black wire with a ring terminal coming off the adapter harness, I have it tied into the harness that goes to the map sensor for some reason. Does anyone have a copy of the original install, or know what this wire is for?
This is the old sub-harness, but the new sub-harness (which is fully plug and play into the OEM igniter connector - no more re-pinning) has the same ring terminal. That small black wire connects to pin B on all coils (sensor ground), which is why you have it tapped into the map sensor ground - as the IGN-1A can compensate for fluctuations in battery voltage. We have a ring terminal added for default for those who do not want to modify / cut into their stock wiring... you can use a clean chassis ground in a pinch, but using a sensor ground is highly preferred.
Everything looks great jhnrx7 except I think you should move your fuse closer to the battery.
Ideally you want the shortest distance to the fuse from the battery in case of a short.
Just curious - what size fuse are you guys using? 30A? 40A?
I ask because I just blew my 30A fuse when I stalled out (???), and couldn't figure out what it was til I found the blown fuse. I have another 30a in there now but wanted to see what you guys use.
Thanks DC5Daniel and Vicoor for the explanations, appreciate the detailed posts.
Alright so now does the below diagram look correct?
And below diagram is technically not correct but does still work as DC5Daniel explained? With the Sensor Ground now ganged with the Secondary Ground.
Sorry just saw this detail - using a 20 or 25a fuse!! Any ideas/thoughts as to why my 30a fuse might have blown?? I'm on the Sakebomb Garage kit. Thanks!!
Hi Guys,
I am looking for a plug and play harness for my AEM IGN-1 to my fd3s since i dont have the time making my self. Which companies make harness for this? I already seen sakebombgarage so are there any other companies making this?
Thanks
Mike
We just got them back in stock and are ready to ship, including our new plug and play set up, which does not require any re-pinning. Shoot us an email info@sakebombgarage.com if you or anyone are interested in ordering.
a testament to how good IGN-1A coil packs are; L1 plug with seriously burnt back/melted away electrode that by all indications was still firing despite the way excessive gap (~3.5mS dwell)
1/8”+ spark gap, lol 😂 .
NGK BR10EIX (6801) plugs that the PO had installed. Not only a pitb to get in/out, but not a wise choice in general for a rotary engine, less so with a high discharge ignition system. Replaced with NGK R7420-10.5 (4857).
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