Donald Cox

Is there anyway to get by without using a third ignitor to get direct fire on leading plugs on 1985 12a? Say like just a parralel jump from leading coil to an added third coil, or is the signal to weak to accomodate 2 coils. Im going to be doing this the suggested way soon but was stuck on the why 3 ignitores question..Also would like to use single gap jump on dizzy using leading wire connections for traling but im not clear on which one would go where or if it even makes a differance..Trying to start a build thread also but my images are too large so guess I need to read more newbie stuff and get it figured out.

gerald m

There are many good threads on direct fire ignition , I will try to give you the basic run down and then maybe just do a few searches and do some reading and then you might understand how things go,, I know it took some patience with some of the members to get my head into it .

Quite simple really The reason you can;t just run another coil on the same Igniteors it just puts extra demand on them and makes for a very lazy weak spark . The first time I did the job I tried to to run the double coil from an 86 with 1 General Motors 4 prong HEI module and it cooked it almost immediately . I swapped to 2 trailing coils from a 86 and ran 2 gm modules From the leading pick up in the dizzy ( yes you can run more than one module from the dizzy pick up signal but from the module you need to run to only one coil )( you can use other types of modules also ,I just picked the GM ones because they are every where and most parts stores have them and they are quite cheap . )For me It makes for a very strong leading spark with no trailing and is simple to work on . There are lots of guys on the forum that have done some very nice ignition changes . Gerald m.

Donald Cox

Thanks for the info Gerald that was exactly what I figured would happen but thought it was a legit question..Im going to build one soon with the GM s HEI s and a separate relay with contacts fed str8 from the battery,and probably not even bother with trailing at all................................. Pain is weakness leaving the body

gerald m

If you need to pass emissions you will probably need to run trailing but not sure .. don't know if you have the FSM's but here is the link .. Foxed.ca - Mazda RX-7 Manuals Have a good one Merry Christmas Gerald m.

Donald Cox

Thanks for that link its really going to help alot as we dont have a manual and looks like dont need one now. Emissions are not needed at all and hope to get it all bypassed and simplified soon.............................................. .................................................. .............................Last words of an Idiot.......WATCH THIS

ghost1000

iTrader: (1)

I run a direct fire/waste fire system without trailing. With a turbo trailing is dangerous do to detonation. As for emissions the easiest way to pass is with an msd ignition. The multi spark discharge 3sparks +a waste spark = four sparks from 1 plug making trailing unnecessary.
A single msd 6a-l or sci-l will replace ur igniter and give a strong spark. It's one of the best upgrades for that car resulting in quick starts and smooth idle.

Run an msd waste fire setup with NO trailing ignition. U'll thank me later. If u want help with carb tuning or a good fuel system for that car let me know

rx7lives

I would use an FC leading coil. That's what I'm doing now in concert with an MSD. Since the FC coil fires both plugs at the same time it appears it's wasting spark but it acts the same way in an FC so I don't worry about it.