Hey guys,

I am a first gen guy and I have been developing a circuit to use our J-109 igniters to trigger the 2nd gen igniter/coil assembly. The circuit appears to work well, but the base of the coil pack gets pretty hot. I imagine that this is normal, but I would like to be sure. I would hate to prematurely burn out an igniter due to excess heat. I guess I am asking if the 2nd gen ECU somehow limits the duty cycle on the coil to reduce heating. The coil itself stays nice and cool. It is just the base of the coil that gets hot. I have the coil mounted on the driver side strut tower. Here is the thread about the circuit:

https://www.rx7club.com/1st-generation-specific-1979-1985-18/transistor-trick-2gcdfis-411312/

Any info would be greatly appreciated. If someone has an infrared temp meter to measure the temperature of the base of the leading coil pack, that would be great.

Thanks.

Kent

 

So nobody knows? I would settle for if the coil parks (base) are hot to the touch, just warm, etc. Just trying to figure out if I need to add some pulse width limitation to the trigger signal to the igniter.

Thanks.

Kent

 

You're going to have heat. Anytime you build up an electromagnetic field and collapse it there is a tremendous amount of wasted energy, that manifests itself in the form of heat. Think of electric motors...

 

Thanks for the input. The coil itself stays cool, so the heating is coming from the igniter. I just don't have anything to compare it to. The 1st gen igniters are on the distributor, so that area picks up a lot of heat from the engine. Since I am using the 1st gen distributor/igniters to trigger the 2nd gen coil/igniter instead of an ECU, I am wondering if the duty cycle that I am running is too high and if I am getting excessive heating from the igniter. I don't want to have igniter failure due to the excess heat. So I am trying to figure out what kind of temperatures does the base of the 2nd gen coil normally see. I just want to compare to see if the temps that I am seeing are normal.

Thanks.

Kent

 

Ahh, OK. Hmm, I've never felt mine to see how hot they get. Wouldn't think a solid state igniter would get that hot, though...