Ingition Coils choices

[sujitroy]

I have a Luminition sytems and it says SUITABLE FOR coils or coil/ballast combinations of not less than 3 ohms.

I have a Pertronix 1.5 Ohm coil and the ballast resistor. It works OK.

For Stag no. 2, I bought a Pertronix 3 Ohm coil and plan to use a Pertronix ignitor. ( I plan to do away with the ballast resistor) I However, the literate which came with the coil, it says it is not suitable for 8 cylinder cars. The literature says for 8 cylinder cars use the 1.5 ohm coil and remove the resistor.

With this confusion, I spoke to a tech at Pertronix and he says the 1.5 ohm coil with ballast wont work, but in my case above it does and the car seems to run OK. I didn't mention I have Luminition. (he probably wouldn't have heard of this brand in USA anyway) Maybe Pertronix coils are made different.

So the question is for Stag no. 1 with the Luminition and ballast resistor, should I just buy a regular 1.5 ohm coil?

Should I use the Pertronix 1.5 ohm coil and remove the ballast resistor hoping I don't fry the Luminition?

Sujit

[Phil S]

if stag 1 is running and you are happy with it why change?
fit the same set up on stag 2 as it's a proven setup

[sujitroy]

if stag 1 is running and you are happy with it why change?
fit the same set up on stag 2 as it's a proven setup

I'm wondering if I remove the ballast will it run better or smoother.

[flying farmer]

It has possibly got something to do with the dwell angle of the two different ignition systems. This is the coil charging time.

If the lumenition has a greater charging time than the pertronix it will flow a greater average current and therefore need a higher resistance combination to avoid overheating.

At low rpm there is plenty of charging time between sparks. At high rpm there is proportionally less time and a far greater chance of the spark being too weak to do its job leading to full throttle high rpm misfires.
The coil needs to be matched to the ignition system.

Neil

[bullstarz]

Back long ago when i was a Luminition supplier (as it was the best on the market at the time but just got left behind when Richard left) the best coil was Lumenition Optronic Performance coil which with the optronic set up could control up to 12 Cylinder but I think that was rated as 10v.

The coil was extremely powerful and the HT spark could easily jump and short out if lead were old or poorly positioned.

[StagJonno]

Think running the Lumenition with a 1.5ohm coil without a ballast resistor will fry one or both coil/ ignition as the heat to be dissipated will be approx x2 the design rating. My understanding is that the Ignitor2 ignition module can run a 1.5ohm coil without ballast resistor as the module can vary the dwell (on time). Personally, if wanting to change, I'd buy a matched coil and module and invest in a good set of leads to manage the higher HT voltage.

[StagJonno]

I've been asked by a friend, who is no longer a member here and thus can't contribute directly by posting himself:

"Please tell them that the green coil supplied with the kit is not for a V8. They do a gold coil that works with 8 and 12 cylinders and is 3 ohms. I have fitted that combination without the ballast resistor. Not done a huge number of miles yet, but seems OK."

Just noticed that you're wondering if removing the ballast resistor will let the engine run smoother - don't think so. The function of the ballast resistor is to allow a system that gives a better spark when cranking and there's a big drop in battery voltage. There's a connection from a contact in the starter solenoid to the coil. This bypasses the ballast resistor and puts full battery voltage across the coil for the cranking period, thus making it easier to fire.