In Reply to: Re: 9N coil posted by Les Leach on April 28, 2018 at 12:17:58:
" At some point I would like eliminate the existing step down resistor and go to a 12V coil. "
As all of us are telling you.........even with a "12 volt ", you still need the oem ballast resistor.
" Also, what is the downside of not having a "stock" resistor in place."
You will melt the coil.
It's in the math, I=E/R.
You need to keep running coil voltage below 4 amps.
You oem ballast resistor is .3 ohms cold, 1.7 ohms hot. The 12v coil is 2.25 ohms. 14.5 volts running. That gets you 3.67 amps.
For a sure start, you need more than 5 amps; the oem configuration gets you 5.7 amps.
The value of the ceramic resistor is unknown, but it's FIXED and is usually around 2 ohms. So, will running current at 3.4 amps is fine, that is also what you get for starting current; it's way too low and will get you a weak spark.
Does that explain why you need the oem ballast resistor?