what do the pulser and lighning coils do on the stator?

[WaveDemon]

replace what's good.
The digital logic and programming for the timing curve is simple (in concept) -
QUOTE]

yup there you go
in concept
but you have to figure out the correction curves for them and that takes awhile

I thought the corrections were for analog inputs. if he's all digital what is he correcting?

 

[Matt_E]

I thought the corrections were for analog inputs. if he's all digital what is he correcting?

The timing needs to be accurate. It's not enough to create a lookup table with delay values.

Example: the current RPM is determined by timing between trigger pulses.
Based on that RPM, you go to a pre-programmed delay before a spark is fired.

But that delay is not the total delay - the circuitry itself will take some time to acquire all signals, process them, etc.
The total delay between trigger signal and spark needs to be determined throughout the RPM range -
And then that delay needs to be compensated for in the curve programs.

That's the only way to have an accurately programmed curve.

 

[WaveDemon]

The timing needs to be accurate. It's not enough to create a lookup table with delay values.

Example: the current RPM is determined by timing between trigger pulses.
Based on that RPM, you go to a pre-programmed delay before a spark is fired.

But that delay is not the total delay - the circuitry itself will take some time to acquire all signals, process them, etc.

OK, if there is an exiting programable ignition for other aplications wouldn't that delay already be taken into account?

I'm not making an ignition. I'm adapting an existing one.

 

[Matt_E]

If you use a pre-existing system such as the megasquirt/megaspark, then yes - the delay should be accurate out of the box.
What I was talking about applies to designing new systems.

However...it would probably be a good idea to verify timing throughout the entire RPM range even with a complete system like the MegaSquirt/Spark.

How is the MegaSpark facilitating the actual ignition (primary of coil)?
Automotive ignitions are quite a bit different from the typical watercraft ignition. You may need to use a different coil than stock Yamaha.

 

[WaveDemon]

However...it would probably be a good idea to verify timing throughout the entire RPM range even with a complete system like the MegaSquirt/Spark.

I agree, I was planning on tuning the rpm curve. I'll start conservative and work my way up. Am I on the same page as you here?

 

[Matt_E]

Yes....I think so.

It might be a good idea to find out how the primary side of that ignition works.
I believe automotive systems use different voltage ranges - which means different coil.

 

[WaveDemon]

unless there is another variable, what does it matter if the box thinks it's at 35 or 36 degrees advance (or what ever # you want to use)? I'm thinking the real # isn't as importaint as the resluts.

how hard can it really be to set the curve. none of the aftermarket ignitions take into account engine load or throttle position.

 

[waxhead]

your right we dont
I am keen to see what you come up with

 

[Matt_E]

unless there is another variable, what does it matter if the box thinks it's at 35 or 36 degrees advance (or what ever # you want to use)? I'm thinking the real # isn't as importaint as the resluts.

how hard can it really be to set the curve. none of the aftermarket ignitions take into account engine load or throttle position.

I am not sure what you're saying.

My point was simply that in a new design (the idea I proposed) I would need to carefully figure out "real timing" and translate that into each curve.

What the box thinks, I do not care. What's important are real advance numbers visible in the engine.

 

[sflsurfrider]

it was POINTLESS.

youre probably right. i shouldve realized it from this gem.....

Coil operation shares some similarities with how capacitors work.

 

[Watty]

I'm interested to see what the latest is on this?

 

[Mouthfulloflake]

WaveDemon.

Use a GM HEI module ( $14)

a Ford TFI style Ignition coil ( about $30)

it will work as is with the pickup thats there, and give a straight curve.

then all you have to do is figure out how to alter the pickup signal for your timing.

hehe

simple right?

:biggrin: