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Discussion Starter #1
Has anyone rewired the ignition coils? I was thinking coming right off the battery with a relay that was turned on with one on the stock power wires. It would be easy to do. I would think that I could get a little more current\voltage to the coils since it would not be running through the harness.
 

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Have you actually measured the voltage at the coil to see if it's worthwhile doing?

The coils only pull a couple of amps. There should not be significant voltage drop in the harness for only drawing that little. You ain't gonna notice the difference between 13.99 (or even 13.9) volts at the coil and 14.00. It just ain't gonna make any worthwhile difference.
 

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The new 09 ZX6 was suppose to come with more powerful stick coils. You might be able to cross over those parts and it be plug and play. Could buy just 1 and see. That was one of my future projects, but never got to it yet.

I really doubt there is any input to the coil current restrictions in the stock wiring harness.

The way coils work is they step up the voltage from say 12 volts to 60,000 volts, but the current steps down the opposite amount, so not a lot of input current needed anyway.
:+1: I found a set on ebay for $100 bucks but didnt jump on them...

Theres the Dynatek ARC-2 ignition system which is supposed to step up voltage and then if you go on the psychobike forums the company NLR has a ignition system coming out as well.
 

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If your air/fuel ratio is anywhere close to where it should be, the strength of the spark almost doesn't matter (within reason). As long as there is "a" spark, it will fire. Making the spark stronger won't appreciably change anything.

Stronger ignition is useful if you are running really lean air/fuel ratio or high EGR (for emissions - but these engines don't do that) or non-standard fuels or with forced induction, etc.
 

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Discussion Starter #5
That is the answers i was looking for. I have not mesured the voltage drop in the harness but it seams like it would not matter from what i gather.

on that subject what is the deal with the arc-2.
 

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If your air/fuel ratio is anywhere close to where it should be, the strength of the spark almost doesn't matter (within reason). As long as there is "a" spark, it will fire. Making the spark stronger won't appreciably change anything.

Stronger ignition is useful if you are running really lean air/fuel ratio or high EGR (for emissions - but these engines don't do that) or non-standard fuels or with forced induction, etc.
The stock ignition of modern bikes is very good. You won't run better or go faster by uping ign output, should you really need a hotter ignition you'd have to be running combustion pressures way beyond 99% of the bikes out there or have the afr really out.
 

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If there was room to increase spark energy with the stock coils, there would be some improvement in power...If your coil/spark is limited due to it's output, your a/f mixture will have to be adjusted accordingly to accommodate the lack of spark energy...so by increasing the spark energy of a given ignition system, you then have the ability to introduce more fuel because now you can ignite the richer mixture...but the engine also has to be able to ingest more air to accommodate the extra fuel...so if air flow is not the restriction and you can add more fuel but the lack of spark energy was the reason you could not put the fuel to it, then increasing spark energy will result in more power...there is a reason why manufacturers are getting away from inductive ignitions and going to cdi ignitons---more spark energy!!
 

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Discussion Starter #9
Great info. so does higher compression need more spark than the same motor at lower compression? Does a 14.1/1 zx10r need more than the stock ignition? I wound assume Hp would not go up much but, easier starting, lower idle...ect?
 

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In theory, yes, higher cylinder pressure will require more voltage for the spark to jump the gap.

In practice ... there is BY FAR more kick in the stock ignition than the bare minimum, so in reality, it doesn't matter "within reason".
 

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Discussion Starter #11
In theory, yes, higher cylinder pressure will require more voltage for the spark to jump the gap.

In practice ... there is BY FAR more kick in the stock ignition than the bare minimum, so in reality, it doesn't matter "within reason".
good to know:thumbsup:
 

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Can't see there being any advantage if you keep the std plug gap, it may be possible to open it up slightly with a stronger coil that may give you a more effient burn
 

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... but only in circumstances where ignition is otherwise marginal. Lean-burn operation, high EGR operation, unusual fuel chemistry e.g. alcohols, etc. For a more or less stock engine that doesn't have an EGR system and is running more or less stoichiometric air/fuel on gasoline, there just ain't any benefit to be found in taking the ignition system beyond stock.
 
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