Everyone uses MSD 6AL. One per coil if running through a distributor or 3 if running direct fire. I MAY possibly run both. I have a GSLSE and am going to switch over to the FC leading coil and keep the trailing stock running through the dizzy. Only because there's no real cheap way to convert to the FC trailing coils.

Anyways, I am looking at the MSD DIS-2. (2 channel vs the 6AL which has 1 channel meaning you could run 2 coils) I was told that the DIS-2 will not work for rotories. Is this true? Has anyone had any experience with it?

 

I've did the 2 MSD 6AL route on this guys EP RX7 ( gigantic street ported 12a with a 51 IDA) and that setup was amazing it ran one box for the trailing through the distributor and the other box ran the leading to one coil per rotor and bypassed the distributor. I will be putting this setup on my street car once i clear up some other bills payed off and the racing season is over with.

 

Maybe the separation between leading fire and trailing fire are too close together for the unit. Not enough time to recharge for the trailing fire. Just a guess. Bang for the buck leading ignition is where the money should be spent. Mazda's stock trailing ignition systems don't seem to need much help anyway.