What is the difference between the "trigger signal edge" in the trigger setup tab and the "ignition spark edge" in the ignition setup tab? I am pretty sure the trigger edge should be falling but what should the ignition edge be?

Thanks
Allen

 

Stock FC and FD use falling on the ignition input trigger edge.

Most dumb ignitors (including the stock ignitors on FC and FD) need a falling ignition output edge.
The only reason to change this to rising is if you're using CDI boxes or some kinda weird, aftermarket smart ignitor?


-Ted

 

I was under the impression that the constant duty/constant charge was the only setting that had to be changed when going from smart to dumb igniters.

 

You need to read the instructions for each manufacturer.
Some of them require a rising edge trigger.


-Ted

 

Thanks for the info Ted. I read the instructions for both the DIS4 and the digital-6 and neither made mention of the type of trigger required to function properly. The problem i am having is that after i zero the timing and while it is still locked as the RPM varies so does the timing. I know if the trigger edge is set wrong the timing will do exactly that but i did not know if the spark edge had the same effect. I wanted to make sure before i just started changing setings. And ALL the features on both MSDs are disabled.

Thanks again
Allen

 

Well i went out to look at the car and check the settings. The spark edge was set on falling so that may be the problem that i have been fighting all along. Thanks again for the help Ted!

Allen

 

With the MSD 6-Series, you will want to run a RISING spark edge(ignition) on CONSTANT DUTY, and a switching after point at/around 50%. You can leave a spark break time of 600ms.

Those Ignition systems operate differently from the stock Ignitors on FC/FD's...