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ignition coil.ballast or not?
MkII - 23/5/10 at 07:11 PM

I want to replace the ignition coil on my crossflow, the existing one is a 12v coil (no ballast resistor fitted), the car has lumenition optronic ignition fitted and the coil lumenition supply for this system is a 9v ballasted one. does it actually matter which I fit, I would have thought more volts=stronger spark or is that a far to simplistic view?

big_wasa - 23/5/10 at 07:27 PM

9v coil will over heat and break down if run cont' on 12v ie no ballast.

MkII - 23/5/10 at 07:33 PM

If I was to fit the 9v coil i realise I would also have to fit the ballast resister that goes with it I was just wondering if there was any reason why fit one or the other.
I should also add the car has run ok for 5 years with the optronic ignition and 12v coil. thanks.m.

LBMEFM - 23/5/10 at 07:52 PM

The coil is 9v and the resisitor is by-passed to let 12v boost the coil for easier starting. If you run the coil with a resistor fittted should be fine, or alternativily fitted a 12v coils on it's own.

02GF74 - 24/5/10 at 08:07 AM

quote:
Originally posted by MkII
I want to replace the ignition coil on my crossflow, the existing one is a 12v coil (no ballast resistor fitted), the car has lumenition optronic ignition fitted and the coil lumenition supply for this system is a 9v ballasted one. does it actually matter which I fit, I would have thought more volts=stronger spark or is that a far to simplistic view?


there is more to it than just that otherwise all the boy racers would be fitting two or three coils in seriles to get Terra Volts out.

going too high a voltage will mean your components need better insiulation to prevent breakdown ... anyways, not saying anymore on that HV is not my bag.

If you have the lumenition optroniic model - optical chopper and unit - then they specifically warn you against using a coil esigned for EFI - these have 1.5 ohm primary resistance. As long as you have your ballast connected you should be fine (I think) but you are loosing energy in the ballast when the engine is running.

... but taking a step back, why do you think you need to change the coil?

a decent set of leads a a new coil will work fine; you can buy lumenition high power coils if you feel so inclined. (there is another brand of high power coil, just cannot recall the name right now).

If you need to "upgrade", then fit megajolt and coil packs.

[Edited on 24/5/10 by 02GF74]

MkII - 24/5/10 at 06:04 PM

the only reason I want to replace the coil is that its the only part of the system I dont know the history of, it was found lurking somewhere in the garage about 6 years ago and fitted just to get the car running,I just want to replace it before it lets me down its quite possible it could be older than I am. .m.

prawnabie - 24/5/10 at 06:28 PM

quote:
Originally posted by LBMEFM
The coil is 9v and the resisitor is by-passed to let 12v boost the coil for easier starting. If you run the coil with a resistor fittted should be fine, or alternativily fitted a 12v coils on it's own.


The ballast coil runs at 9v so it doesnt see a drop in voltage when the starter is turning over.

ShaunB - 24/5/10 at 09:41 PM

A ballast coil will give you a stronger spark whilst starting, but once running you won't notice a difference. Unless you have starting problems I'd stick with the 12v coil else you'll probably have to change the solenoid and adjust the wiring to bypass the ballast resistor during starting.

02GF74 - 27/5/10 at 07:25 AM

what ShaunB says. ^^^^