1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Direct Fire Question

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Old 11-13-03, 02:51 PM
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Direct Fire Question

I have been trying to keep up with this direct fire rave that everyone is talking about and I can't figure out which setup is right? Iv'e seen setups only using 1 coil, 2 coils & 3 coils. So which way is right/the best? If it makes any difference I have a 84 gs. Thanks in advance.




Old 11-13-03, 02:55 PM
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im interested as well.
Old 11-13-03, 03:30 PM
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3 coils
im doing jeff20b's version
Old 11-13-03, 06:22 PM
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Alright, here is the deal:

1 coil...that simply isn't possible. Aside from the distributer there are two seporate ignition systems for your rx7. One is for leading and one is for trailing. You need at least 1 coil for each.

2 coils...what you have seen here is probably a stock coil for the trailing ignition, and one fc or fd coil for the leading ignition. I have only seen a couple setups done this way, and I am not sure if they are still running.

3 coils...1 coil for the trailing, run through the dizzy, and 2 for the leading. There are a few variations with this one, the most common being dlidfis.

dlidfis - dual leading ignitor direct fire ignition system (see why it is abbreviated) basically you wire 2 coils, and 2 ignitors to fire off the leading plugs in wasted spark mode.

slidfis (pmdfis) - single leading ignitor blah blah (poor mans blah blah) use 1 ignitor to fire 2 coils, i don't know if anybody is doing this right now either.

CDI DFI - capacative discharge ignition (MSD) direct fire - using a CDI box to fire off the two coils.

Alright that is the general stuff, do you have any specific questions?

I am using an MSD 6a box firing off two MSD blaster2 coils, it works alright for me but i haven't compared it to anything but stock, and it was a slight improvement in idle and overall smoothness.

-Marques
Old 11-13-03, 08:54 PM
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is there a simple CHEAP way to direct fire all 4 plugs ?

I want to get rid of the distributor cap entirely, without spending much money.
Old 11-13-03, 09:06 PM
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Click and ye shall be rewarded:

The FAQ dost have all the answers that thou willst desire.

https://www.rx7club.com/showthread.p...hreadid=237777
Old 11-13-03, 09:24 PM
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Originally posted by MosesX605
Click and ye shall be rewarded:

The FAQ dost have all the answers that thou willst desire.

https://www.rx7club.com/showthread.p...hreadid=237777
well, not MY question.

at least I read all the threads and all the setups use the distributor for the trailing plugs.
Old 11-13-03, 09:34 PM
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Originally posted by mwatson184
Alright, here is the deal:

2 coils...what you have seen here is probably a stock coil for the trailing ignition, and one fc or fd coil for the leading ignition. I have only seen a couple setups done this way, and I am not sure if they are still running.
My (FC coil/2nd Gen coil/FCDFIS) is running perfectly. I chose this setup because it's very simple to setup and has minimum components, wiring and connectors. Simpler the better.
Old 11-13-03, 11:56 PM
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sold the FD...kept the FB

 
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Originally posted by inittab
My (FC coil/2nd Gen coil/FCDFIS) is running perfectly. I chose this setup because it's very simple to setup and has minimum components, wiring and connectors. Simpler the better.

I could'nt agree more. My FDDFIS has been running strong for a whole year. There is absolutly no advantage to wiring another ignitor. Stock mazda coils are high quality...Cheap aftermarket coils like Blaster 2 units are junk.
Old 11-14-03, 12:05 AM
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I'm going to venture to the whole DLIDFIS. I just bought another ignitor on Ebay and I'll probably grab another good stock coil if I can find one just to get it all started... then I'll upgrade coils later.
Old 11-14-03, 12:56 AM
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honegod.

if you direct fire all plugs at once i believe it is impossable for performance. my understanding is the trailing needs to run off the dizzy because the the spark would happen in the intake point . so you will be firing when gas is coming in. the leading plugs are right past the intake chamber so it fires on exhaust. yeah that sounds screwed up. hopefully i didn't confuse you more.
Old 11-14-03, 01:28 AM
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ok, here is the link that will explain it better than i could.
https://www.rx7club.com/showthread.p...hreadid=240653
Old 11-14-03, 01:28 AM
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Originally posted by kettlman
hopefully i didn't confuse you more.
naaw, , that is how I am understanding it.

I just WANT to get rid of the distributor cap and am hoping for some magic
Old 11-14-03, 02:25 AM
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Well, there is a way to run direct fire with only one coil and no distributor cap. Use an FC coil on leading and don't run trailing at all. Hehe.

By the way, I just picked up an FC leading coil yesterday and I'm going to use my MSD 6AL on it. I also picked up a spare Diamond coil. Since I already have a spare J-109 ignitor, I'm all set to have a rev-limitable ballast resistorless ignition system (where the L/T split won't matter too much).
Old 11-14-03, 04:01 AM
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I've been following these threads on DLIDFIS for awhile. All I need now is a coil and I can hook it up on the GSL-SE.
Old 11-14-03, 04:10 AM
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Lapping = Fapping

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Old 11-14-03, 04:37 AM
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heh, my main thrust was to make the hall effect dizzy shorter, the cap is a TALL sucker.

it just occurred to me that it is possible that the cap and rotor from a POINTS setup should fit, and work for a DLIDFIS setup.

I have all the above available and will check for fitment when I wake.

any idea on how well it would work, if it fits ?
Old 11-14-03, 05:10 AM
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unfortunately, install will have to wait til after the car runs so I know if I fudge the install. Heh.
Old 11-14-03, 01:40 PM
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The points cap may have little tabs on the inside that you'll need to remove. I used a dremel tool.
Old 11-14-03, 07:15 PM
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I picked up an FC trailing coil today. I'm going to hook my FC leading ignitor to it so I can save the precious J-109 for another day.




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