Hey @Shaggymech, I appreciate your enthusiasm but do me a favor a slow down juusssst a hair. I know you’re pumped and doing research fast, but much of what you’re posting is incorrect or inapplicable to NanoEFI. I’m a big quality over quantity man and prefer slower more deliberate conversation.
That said, I think you’ll be very happy with the answers:
A good question paired with an incorrect assumption
Not half… NanoEFI is able to generate both positive +12v and negative -12v sides of the trigger pulse just fine.
Further than that, you can can also set whether the generated pulse for the CDI is produced negative-first, or positive-first. It’s a toggle in Airtune’s GUI.
Speaking specifically to the GY6 AC and DC versions, both trigger exactly the same.
And also generally speaking, although there are many (many) variations out there, there is no “AC” specific trigger, or “DC” specific trigger. When you hear “AC vs. DC”, that’s referring to the power source. Not describing the shape of the trigger signal.
I’m not looking to officially support so many different types of CDIs. It’s just not practical. So my default answer will almost always be to “use the perfectly good and well tested CDI included in the kit”.
It’s best to let NanoEFI handle the intelligent bits of ignition timing, we just want a dumb reliable (and affordable) CDI to produce a spark when we tell it. Also it must be cheap enough to keep spares on hand, and readily available brand new.
I should say that it’s important not to confuse cheap with inadequate. NanoEFI has my name on it, and I won’t send out parts that need to be upgraded in order to work as expected. The CDI I’ve selected for NanoEFI is the original version GY6 DC CDI from 15 years ago. Before the design was iterated into the ground to reduce costs. The newer versions are the poorly performing nonsense you see all over eBay and Amazon these days. I have a lot of history with this unit both personally and professionally. It’s rock solid, priced exactly right, and sourced through my long standing supplier by the tens of thousands.
With that said though, just because I think a certain way doesn’t mean I’ll lock others into that paradigm if there is a practical way to keep other options open. So you’ll still be able to use other CDIs if you’re interested doing the legwork to dial it in. However, I’m not in a hurry to implement the CDI learning/mapping feature. I consider this beyond the scope of our initial release and it’s not a part of my plans for the near future.
Especially during BETA, I want everyone running as close to standard gear as possible. Doubly so when it comes to ignition and the potential for serious engine damage if guys are getting too experimental too soon.
That’s the plan. Only DC though. There aren’t any practical advantages to including an AC CDI option, but a lot of potential for compatibility headaches.
And I don’t want to manage more SKUs than necessary. Lean is king.
For updating most older systems, just use the included CDI and coil. You could call it an overhaul, but that conveys more hassle than it actually is to convert. Or don’t convert, and keep the points. Either way is fine.
The more critical issue is making sure to supply the ECU with an appropriate source of trigger timing from the crank. For simple installs NanoEFI supports sensorless trigger sources, even right off of the kill wire.
For more advanced installs, linear hall sensor input works right now with a bit of external circuitry. I still have decoder work to do for N-2 patterns, but this will be ready and buttoned up before BETA.
Use the CDI!
It’s important to avoid assuming that everyone has the same goal. The level of precision you’re asking for already exists in NanoEFI. But we should all be careful asserting a “right” way (especially myself). Everyone is going to have different expectations and only a certain amount of complexity they want to deal with. We should allow people to get as advanced as they feel ready to tackle, as they’re ready.
I prefer tight ignition control personally, and tend to spend too much time chasing zeros if I’m completely honest. However, for every one of us interested in nailing theoretical optimals, there are 9,999 others who straight and simple just want to ride each and every time they turn the key without fail. With minimal tinkering and the least wrench time possible. That requires that we loosen up on certain aspects of control so our tolerances are forgiving to the widest degree of skill levels, and variables in the field.
So in the end, you have the basic option to run sensorless triggering which allows for ignition timing of around ±1° and a painless installation. Or fabricate a 60-2 or similar encoder wheel setup and get sub-degree precision. The advanced features are there for those of us wanting them. And entry level functionality for the rest of us just wanting to kick that old smelly carb.
Speak for yourself man, I’m after a bit of healthy decel pop and gurgle
In the end “to each their own” is what matters, my role here long term is to provide the feature set and flexibility to do both.