inittab

I hooked up my 15 dollar direct fire ignition today. It was pretty much a no-brainer job too. At present I'm firing the coils with my stock J109 ignitor but eventually I'll wire up the 2nd gen ignitor that the coil's currently mounted too. Oh.... I also jumped my trailing wires on the dizzy over to the leading terminals. The most noticable thing is the engine idles smoother with a little less jumpiness. The car pulls as strong as it did before, not much difference there. The main advantage is that I've bypassed the weak-link dizzy cap.

Here's a pic of what it looks like.

Redwood

That's badass. Nice job, and good mounting point. I wish my 2nd gen coils were mounted that well.

nimrodTT

I run the second gen coil on mine as well. Don't expect the pickups in your dizzy to fire the 2nd gen ignitor, because it won't.

85RX7GS

iTrader: (1)

Woohoo! Nice work!

inittab

That was the only reasonable mounting point I could find. I used an existing tapped hole for the top and I drilled a hole fo the bottom. It ain't budg'n.

inittab

Maybe I don't understand it fully (which is the case BTW) but I would think that it would work. I guess you've tried this..... what was your experience?

nimrodTT

The signal coming from the pickups won't fire the ignitor. I tried it; it didn't work. If you figure out why, let me know.

abeomid

The signal in the second gen is coming from the ECU I believe which gets it from the CAS (Crank ANgle Sensor). This signal is a different signal than what the magnetic pickup send in a 1st gen. So there is almost no way to get it working unless u make a little computer that can translate the pickup signal to 2nd gen

inittab

ah ha! And then there's the question of "is it all worth it?"

Jeff20B

iTrader: (13)

I'd say, "nope!"

Glad to see you got it working with a 2nd gen coil. But you say it pulls just as strong as before. Hmm, well I can tell you mine with two stock 1st gen coils (and two J109s) pulls stronger than it used to. I'm sure it has something to do with having seperate full power sparks to each plug.

inittab

Keep in mind that I'm pretty sure it's leaning out at the high RPMs. My observations stand but untill that issue is fixed I'd take it with a grain of salt. My next project is a new fuel pump, regulator and some re-jetting.

Another observation: On my drive into work today I noticed that the engine runs much smoother at cruise speed. Steady as a rock you could say.

Hyper4mance2k

iTrader: (40)

"So there is almost no way to get it working unless u make a little computer that can translate the pickup signal to 2nd gen "

its only binary ode just some 1's and 0's

Maguire

iTrader: (1)

whats the main advantage of using the second gen ignition over they 1st? MSD, homemade Directfire? Is there a diffrence between it all? My ignition is kinda screwed up right now, so im looking for another alternative. Sorry for the novice question. Since the topic was up i thought it couldnt hurt to ask.

inittab

2nd and 3rd Gen RX-7's and pretty much all new cars nowadays do not have traditional distributor caps like our 1st Gens. On these newer cars, the coils fire the plugs directly without having to jump a gap in the distributor. Thus the name "direct fire". The main advantage of direct fire is that there are no parts to wear out and the plugs get the full juice of the coil. These two reasons alone make the setup superior to the traditional cap-n-rotor design. If you do a search on this forum you'll find all sorts of opinions about how to setup direct fire ignition. The 2nd Gen coil method that I used is probably the cheapest and easiest to setup. There is also the DLIDFIS method which is more complicated but apparently effective and then there is always MSD.

inittab

So I decided to forget about trying to hook up the 2nd gen ignitor. It just ain't worth it IMO. So to reduce a little weight and make the installation a little cleaner I remounted the coil pack. I removing the ignitor pack that was sandwitched between the coil and the mounting plate and replaced it with aluminum threaded stand-offs. Came out pretty good. I think this is how's it's gonna stay.

Maguire

iTrader: (1)

Thanks for the info. Ill look into this further. Why did you opt not to use the 2nd gen ignitor? If your not using the Dizzy why are there still wires running to the distributor cap?

damon

You still need the dizzy for the trailing spark, only change is each of the leading plugs has its own coil

peace

inittab

Just as Jeff20b predicted in another thread, my J109 ignitor blew. I even drove it for 40 miles on the trailing ignition only..... I didn't know it could do that! Now the question is why did it blow? Are there any electrical / electronic / ignition gurus out there that can answer that question?

BadAssRX-7

so whats all done to the stock fc wiring and the fb wiring to get this to hook up right? you just run wires from the stock ing. to the fc coil?

inittab

Yes, I ran the wires from the stock leading coil over to the FC coil. I'm glad I had a spare ignitor on hand.

REVHED

The reason the ignitor blew is because the 2nd gen. coil draws more current than the ignitor can handle. This is due to the fact that it has a lower impedance than the standard coil.

inittab

Makes sense REVHEAD. Okay, humor me... so forgetting about practicalities for a moment..... and understanding this apparent incompatability between these devices, how could this be fixed? Just curious....

REVHED

The simplest way I guess would be to put a resistor in line with the primary winding to raise the impedance slightly.

Just a question though, did you use thermal paste on the back of the ignitor? Because, I've heard of people running the 2nd gen. coil successfully so the current draw must be pretty close to what the ignitor can handle. Maybe, not using the paste causes just enough heat build up to fry the ignitor...

inittab

A resistor eh? That's kinda what I figured.... how could I find out what size resistor would be needed? And, no, I did not use any thermal paste. The paste that was on the back of the ignitor was most likely 17 years old.

inittab

Bring out your dead! *clang*

Okay, I'm hell-bent on getting this direct fire 2nd Gen coil to work. Well.... hell-bent or stupid...

Anyway....

I was tinkering with my rex today and decided to take a good look at the 2nd gen ignitor circuitry and lo and behold, there's a resistor in-line! The resistor reads "5W 0.35ohmK --- MICRON 94". Here's a pic.



So I slapped this ol' direct fire setup back on with the resistor in place. So far so good but I've only driven about 15 miles. The car pulls REAL strong in the high RPM's now.

I'll keep ya'll posted on how it performs.

--Bob