Interesting mod on rotor... suggest upgrading to 81-85 distributor for a better/cleaner/stronger signal output. Upgrade the ignitors to a 4 pin HEI ignition module for a hotter/longer spark and use a relay to power all the ignition modules/coils and take load off the ignition switch and yet another increase in spark power at the plugs. Read back thru this thread to see t g's findings & solutions.

 

Well, techinically, he can keep using the 80 dizzy if only using the stock 80 ignitors. The FB dizzy
is only needed for the non-stock ignitors.

 

Understood t g,while op did waste spark with a minimal investment & has an improved waste spark leading ignition, it could be stepped up with HEI ignitors etc...

 

No. A common problem with aftermarket rotors is the fact that the posts in the cap have a narrow range of timing change compared to where the pointers of the rotor line up. Even a factory rotor will only go to 20° BTDC where the pointer moves away from the post. This puts a direct conducting path from the pointer to the post to at least 40°BTDC.

I don't see any issue with the amount of spark here. I am using a 0.035" gap on all my plugs BR8E... type NGK. The engine is turbo-charged and so far it never misses a beat.

 

Sounds like an interesting mod for trailing. I will say the trailing doesn't add much to
the power produced but does help cleanup the tail end of the burn. Less stinky with
it in my experience.

Well, if your turbo setup does have ignition issues, you are all set to move up to
better setup with just an ignitor and dizzy change. Nice to see folks still pursing
and improving on this stuff.

 

I am using an extreme negative timing split in vacuum for this engine. The idle setting will hold 30°BTDC on the trailing, where as the leading stays near 0°TDC. This mimics the electronic maps that are quite popular for many users.

I got a set of RE7C-L (RX8) plugs for all positions this weekend. Wow what a difference. Not only does the engine idle better, It will now start with authority when 'Hot'. Prior to this, the engine was prone to flooding when hot. I was suprised to see these plugs are pre-gapped at .048". I don't know how a guy would gap these either, so I just put them in.

 

3 new MSD Blaster2 coils and 1 balast resistor. 2 1980 ignition triggers. One trigger fires 2 coils for the leading timing and the other trigger fires the trailing coil through the resistor. The old coils made a faint blue spark. These coils make a spark that looks like a lightning bolt! The coils are firing NGK RE7C-L spark plugs made for the leading position on the RX8 engine. WOW I have never seen this engine come to life this quickly HOT or COLD.

 

Yeah those RX8 plugs make a big difference and should last longer.

 

So my 79 has been acting up this summer. Tach would randomly drop to zero which immediately became apparent that my leading ignition was cutting out. My plan was not to just fix what was wrong(either the coil or ignitor) but to upgrade. Previous owner had already upgraded the car to an 81-85 distributor so TFIDFIS was where I went.

Thoroughly impressed. If I didn't drive the car for a couple days, it would always require a shot of starting fluid to get it to fire, then a few more shots and a long warm up to keep her running.
So after doing the install I figured I'd give it a real test. Start it, no assists, just a pump of the gas pedal and BAM started right up, impressed I got the wiring all right on the 1st try too! . No repeated start ups needed, followed by a long warm up.

For driveability, I noticed the car just seems smoother on throttle response, the hesitation when I would hit the gas is gone. No more having to give it a blip when shifting to neutral to keep it running.

I also noticed the exhaust, while still that special RX-7 aroma, didn't have nearly the raw fuel smell it used to.

Two "weird" things I noticed after the upgrade. When I hit about 6700rpms(which I rarely take it to the buzzer), the tach then jumps to max. Not sure why, no lurching or anything. Currently have the tach wired up to the trailing coil, but I might have something not setup right I'm thinking. Prior owner when taking out the points distributor had some extra wires, and disconnected, so I'm going to have to figure out if I got the right wires for the tach.
Another thing, I disconnected the trailing ignition to prove that the TFIDFIS was working, and the tach read double the RPMs. I'm guessing to do with the issue above and the tach.

For the install, I made a bracket using a couple 2" angle aluminum pieces. Bolted everything up to that, and then mounted that to the Racing Beat strut tower brace using another piece of aluminum to sandwich it to the brace. No holes drilled through the brace. The TFI connectors, I swapped around the +/- cable connections so I could hook it up to +12V and the HEI without having to eliminate one extra connection. This was a fun little project

Switched to the RX-8 plugs today, since I don't remember the last time I replaced the stock 85 plugs. Not sure if I noticed a difference after the 1st giant leap. Longer life at the very least will be a nice benefit.

Thanks t_g_farrell for this thread, and Xamnglc for the updated wiring diagram and to everyone else with their install pictures and comments. Really helped with coming up with install ideas.

 

Nice to hear. Try hooking the tach to the one of the leading coils and see what it does.

 

thanks for the clear picture, is there an advantage is using the relay? I just jumped a lead for the black/white wire on the OEM leading coil to the new HEI plus/IGN coil plus circuit. that black/white wire is very thick!

For my 4 pin HEI ignitor, Distributor green goes to new HEI w-pin, Distributor red goes to new HEI g-pin.

last week the oem leading ignitor crapped out. I had a spare from 1998, that I got from a tire shop. the tire tech pulled it from a rx-7 that was going to be chopped up by the fire dept for practice. And I had to get a new J109 from the dealer to pass the smog test in 1996. I was so pissed that I took off the air pump and catalytic converter after passing.

 

The relay takes the load off the ignition switch AFAIK. Another of example of adding (easily replaced!) relays to the stock wiring so expensive rare parts aren't overly degraded (like your ignition switch).

I could be wrong.

 

Toruki has it right. Its to reduce load on the old wiring and to provide a less resistant path for that direct battry connection to the stronger coils. I would thing with the extra power the coils require, with the relay, you may put even more stress on the old wiring and ignition switch and/or reduce the juice to the coils. I know this all seems like magic at first but once you get it down, its not that hard.

BTW, I owe this thread some love to cleanup some diagrams of my own and provide some explanations of things. I want to thank everyone who has jumped in here with their own drawings (which are better than mine) and helping folks get this going. Truly a community effort. This is what 7club is all about.

I can't believe its been over 10 years since I did this. I won't take the credit, I just collected all the wisdom from here and other places and tried to pull it together. I write these things up for myself more than anything so I have a clear record or plan of what I'm doing or have done.