Thread: Inductive coil tech, coil-on-plug (COP) tech and more.

yeah true, but it shouldnt be too expensive. Im almost wondering if 4 b13 coils would suffice since they will have a longer dwell. Trigger them with a rwd sr ignitor or Q45 ignitor. As long as in the aem you can program your coil dwell time to optimize the spark output.

Ben would be the one to answer that question or someone else with more aem management experience.

The b13 coils seem pretty powerful as they are. I didnt even have signs of spark blowout, 8k rpms, 30 psi from the 60 trim, and a/f ratios in the 11.3:1 range with C16.

Yah that would have likely worked just fine then. That really surprises me that Nissan did the RWD SR20s that way. The coils themselves have 3 wires correct? What the hell are the three wires for if not power, ground, and signal? Do they not have built in "ignitors" giving them that 3rd wire? Why the hell are the ignitors there if the coil already has them?
Makes no sense to me...


It's because the motorcycle coils don't bring the voltage up nearly as high as your stock coil, or automotive COP. Read the first post in this thread for more details on that. Maybe just read the "Motorcycle COP and why they are different." section if you're in a hurry.

The RWD guys with their COP likely can do a bit more power than us FWD guys with our single coil. I agree you're right on the edge there at 550+WHP. The RWD guys can probably get to 600+WHP maybe.

With you and your goals, I'd just jump straight up to the big boy toys and do a CDI box plus motorcycle COP. (Again, read the first post in this thread to see why.)


Yah I could have sworn we've been over this before. For you I recommend the best ignition setup in existence right now. It's not too expensive. The CDI box is the only real expense.
I promise you once you've read the first post a lot of your questions will be answered.

Yah this is also an option, but likely just as costly as the better option I've recommended. I wasn't sure you were looking to do a coil-near-plug setup. If you're willing to do it then it's an option for sure.

What do you think about using 4 individual good coils? The CDI box is basicly to increase the primary voltages basicly then correct, to make a hotter stronger spark.

As far as the 3 wires on the normal s13 s14 coils go, you have your 12v input in, 12v output to the ignitor, and a common ground for the coil itself i believe that is in relation to the primary coil as kind of a backup ground to prevent surge or something of that nature.

The s15 coils with the built in ignitor are 4 wire coils. first three are the same as the 13 and 14 coils but the other is the wire going to the ecu instead of the ignitor to trigger the coil. Basicly its just built into the coil.

Im really having a difficulty debating. I love the clean look of the small motorcycle COP's but they are very small and again if the only way to up the spark output is a CDI box then thats a possibility or i might just go with the 4 large coils and some good wires.

They would be an improvement over the stock setup if you did stock B13 coils in a coil-near-plug configuration. And maybe it would be enough to get you to 700WHP. And if you're on a tight budget, it might be worth trying as a potential solution.

Yep.

Yes you can, but dwell is either "not enough" or "enough". Once you get "enough" dwell time, no more is going to help. It can't dwell longer and make a stronger spark. So fixing a dwell time issue only gets you a little bit and only at high rpm.

It is quite good. It has it's limitations however. The whole stock system does. Recognizing which issue you're running into is key to finding the right answer. Are you running out of dwell time or are you lacking voltage?
Basically, if you open up the gap in the plugs do you break up everywhere, or only at high rpm? If everywhere, you have a voltage issue and you need a stronger coil or charging system. If you're breaking up only at high rpm it's a dwell time issue.

When i had the plugs gapped at .032 on the dyno once i got to 22psi it was cutting out just after peak torque and full boost. We lowered them to .24 and never had issues. So I would have to say that it was from 5500 rpms to 8000 that was sputtering out under that much boost. Like you said it may not have been a dwell time issue but rather just not enough voltage.

And again you mentioned different types of coils have more and less voltage output correct?

So if the B13 coil itself cant keep up with say much past 550whp then i would need a stronger coil or a CDI box to up voltage.

Hmmmm debating debating. I kinda want to get settled in on what im gonna use. I really dont want to buy 4 msd blaster coils as they are 80.00 each. If you know of a much stronger coil than the b13 that comes on a factory car i could try those out and run them without a CDI box and go from there.

Hard to tell. If you were okay at peak torque but not afterward that sounds like a dwell issue due to lack of time or overheating of the coil. Doesn't sound like a voltage problem exactly. But voltage problems could be just another 10WHP away... =/

Yah like those aftermarket "better" coils, they have more windings so they will put out a bit more voltage than OEM or others.

Yes.

Sorry, I have no idea sorry. But you're on the right track.

I am not following you. The post before this one you quoted (and what I was refering to) I listed an individual external coil. The problem is they are expensive and bulky (have to build rail to mount 4 large coils on, etc).

wnwright maybe I missed that post about the IGN-1a race coils. You say four of them work better than any CDI+COP system you've seen? Sweet. Something tells me they might not charge as fast as a CDI system, but it's not like we're going into the 15k+ rpm territory.

If those coils are that good, then it sounds excellent.

I wonder how well the LS1 coils do. Man i need some suggestions. I have two spare b13 coils sitting around but again if im gonna have issues id rather not use them. ill have to do some looking around at some coil options.

Question is this. With the motorcycle COP with a CDI box, how good will the spark be on those and what do you think they will be good to if i go that route.

So its either $100 for the COP, <$300 for the CDI box and im set
Or 100-200 for coils, $25 for ignitor, $100 for good wires