Triumph Repair: installing electronic ignition, electronic ignition systems, electronic ignition system

Question
Sir,
I have planned to install an electronic ignition in my Triumph Spitfire mk2 (1965).
I ordered an 123 ignition system from http://www.123ignition.nl/
and a new ignition coil BERU ZS109 (Ignition Coil Coupling Type DIN - Ignition Coil For pre-resistance Voltage [V] 12).
On the boy of this coil however it is stated "USE ONLY WITH BALLASTRESISTOR 1,8 OHM".
Does this apply to use with electronic  ignition too or only when used with the standard mechanical distributor?
What would be the best option to connect the coil?
best regards and thank you in advance for your prompt answer.

Answer
Hi Luc,
I don't know anything about your new electronic ignition system (123 system). However, I can tell you most of what to do. You MUST read the instructions that came with the new ignition system as it will tell you what coil MUST be used with that system.

First the reason low ohm (low voltage) coils are used. Every time you see a low ohm (1.3 to 1.8 ohm) coil used it is because the ignition system was designed for it with some kind of resistor in the system. Most electronic ignition systems use these low ohm coils (some times called 6v coils)Most igniters (electronic ignition system)use a low ohm coil.

And some cars have a bypass system built into the car so that when you are in the "Start" position a resistor is bypassed and current is applied directly to the low ohm coil. This does not harm the coil because in the "Start" position there is NOT 12v available from the battery due the starter drawing much of the power. As soon as you release the key to the "Run" position the power supply no longer bypasses the resistor and now the resistor drops the voltage to the coil thus keeping the coil from over heating and causing too much voltage being applied to the electronic ignition system.

I don't believe the older Spitfire used the bypass system in 1965 and especially the Euro version. So your car probably had a 12v coil on it and no resistor. Since you know that you must use a 1.8 ohm ballast resistor from the statement on the coil you must read the directions from the ignition system (123 Ignition)to see how to connect it up.

DO NOT connect it up without a 1.8 ohm resistor unless the manufacture says you can do that. If they require a 1.8 ohm resistor but don't supply one, you should be able to get one from any auto parts store as ballast resistors are a common item on many cars. If all else fails, get a 12v coil that does not require a ballast resistor from any auto parts store and use it.
Howard