rxseven

Recently, I read about a guy who used a 2nd gen coil pack for a direct fire set-up for his first gen, keeping everything else the same. Has anyone here done this? Any positive results from this?

Darius
85-SE

Brian P

Sure you could, you'd only be able to use the trailing coils though, the leading both fire off the same coil and the ECU tells the coil which side (L1 or L2) is going to fire.

I can't see there being an advantage over any aftermarket coils though. Only if you had them lying around, it might be worth it. I'd just go aftermarket

Jeff20B

iTrader: (13)

There are plenty of great results from going to direct fire. Infact, I'm thinking of going direct fire on the Trailing, but I wouldn't recomend any of you trying it until you learn the basics of rotary igniton systems.

To keep it on topic, the resistance of a 2nd gen Leading coil is too low for a 1st gen ignitor. But I would recomend installing a 3rd ignitor and using two stock style coils on Leading. Care for more info?

P.O.S. Racing

From what I’ve heard your basically firing the plugs from the igniter, have seen it on a car around here, he used Miata Coils.

Jeff20B, can we get a readers digest version of the set-up?

RX-Midget

Good luck!

jimmyv13

Why are you thinking of going to direct fire on the trailing only???

The site is Dual Leading Ignitor Fire Ignition System

Felix Wankel

I think he means the trailing in addition to the leading. I might attempt it if I can fix my MSD box that committed suicide. I just bought a new one the other day, so now I have two.

jimmyv13

I see...


What are you using the MSD's on?

Felix Wankel

I was using a 6A, running direct fire on the leading. It smoked itself, so I had to get a new one. I'm gonna see if I can fix the old one and try to use it too.

madaz07

on my friends car on of the ignighters went bad on the dizzy so we took it to the guy who built my engine and he used ignighters from some other car and ran wires from the pickups to the ignighters that were mounted on aluminium on the strut tower. But it only uses 2 ignighters still running through the dizzy. It should be easy to convert it to direct fire as about 3/4 of the work is done. Just need to get another coil and the same ignighter

Jeff20B

iTrader: (13)

madaz01 has the right idea. I almost did that back in '98 but decided against it because I didn't have the right parts/tools. I had planed on mounting the ignitor on the coil holder with an aluminum heat sink. I built a makeshift heatsink drilled properly to fit an ignitor but never finished the project due to lack of knowledge/research. Heh, that's all changed now.

A reader's digest version? uh, I think jimbo would be better qualified. He does good sumaries.

Here is probably the reason why Felix's MSD died on him. Imagine hooking an amp up to two 4 ohm woofers in parallel. The amp sees a 2 ohm load and therefore gets real hot and you know the rest. It usualy croaks. Well, this is exaclty what you're asking the MSD box to do. Hooking it to two coils when it was only meant to be hooked up to one. At least amp makers now build amps that are 2 and 1 ohm stable.

Yeah, I meant direct fire on both. I already know how to make it work. I just need to set up the parts.

Felix Wankel

Actually I had it out of the car when I had the motor out. When I put it back on it made a weird squealing sound, and smoked itself shortly thereafter. I'm well aware of parallel and series wiring (from doing car stereo), and I don't believe having 2 coils on it killed it. It worked like that for a long time. The fact that it was covered in engine oil from a major leak probably didn't help either

madaz07

Hey Jeff20B i was talking to someone about the directfire setup for the leading and they it would work but as each leading spark plug is getting the same signal one would fire on compression and the other would fire in the wrong place like an apex seal. He recommended not to do it. correct me if im wrong but that is how i see it from the diagram.

Jeff20B

iTrader: (13)

Felix, I think the oil is what killed it too. Was yours mounted 90* or horizontal? The instruction pamphlet says the MSD should not be mounted upside down because it won't be able to drain properly.

Mine was mounted sideways or 90* (whatever term you prefer) for a few months but I removed it because it caused more problems then it solved. The low end was the same as it was with two coils hooked in series to one ignitor. Only the high end was better up to 6k RPM (due to a weird carb).

I still have the same rev range with dual leading ignitors but now I have more power everywhere in my powerband, especialy when my secondaries open. Oh man it feels like an extra rotor kicks in! I also had great power up to 7.5 to 8k RPM last night as I was test driving my friend's 13B which I recently installed DLIDFIS on. I don't want to rev his engine that high all the time because the apex seals are old. I'll let him be the one to throw an apex seal Ahem jokes aside, his engine leaks compression into the water jacket so it'll need a rebuild soon.

So that's two engines that I've hooked up and they both have stock carbs and way more power than before. I can't wait to set this up on a friend's 13B with a modded Nikki on it. That oughta hold those doubting SOBs. (joke)

Oh yeah, I'm gonna try it on an engine with a Camden/Atkins supercharger soon.

madaz07, yeah, I'll correct you. As long as your total advance never goes much beyond 26* degrees ATDC or so, it will always run excellent with direct fire. With all due respect, your buddy is ignorant. What, did you want me to sugarcoat it?

I'm not sure how far off the timing needs to be in order to fire into the wrong rotor chamber, but I don't worry about it at all.

We all know how particular Felix is about the names of the cars we love so much, whether it be Cosmo instead of RX-5 or RX-7 instead of rx7. That's why I propose that running a rotary in direct fire on Leading should not be called 'wasted spark' because a rotary isn't actually in the exhaust phase yet. Infact, when the extra spark ocours, there are still a few degrees left before the exhaust port even begins to open. I started out calling it double fire or dual Leading fire for lack of a better term.

So to use that term effectively, there is no way to run the Trailing ignition in "double" fire using the 90* reluctor as in the stock dizzy. This is due to the Trailing plug location. It is too high in the rotor housing. However, you still can run direct fire to the Trailing plugs. Just not in double fire mode.

One more thing. We have RHD and LHD vehicles (where the steering wheel is). Yet when we describe a prob under the hood, some of us always say the driver's side or the passenger's side. I propse that we start calling it the plug side, or the intake/exhaust side. That eliminates all confusion. Only a real Wankel engine has those reversed (well, the small wankel engines I've seen over at Atkins do).

Felix Wankel

I had it mounted horizontally. I think what happened is that it got turned upside down while it was off the car. I didn't know it had oil in it until I took it apart after its untimely demise. I'm still going to try the dual ignitor setup too. Then we'll have a good back to back comparison on the same car

Jeff20B

iTrader: (13)

Cool, please keep us posted with your results.

I'm going to take pics of the next ignitor plate I build. It's going onto my friend's GSL-SE 13B powered REPU. It's the one with the Nikki on it I mentioned earlier. Yep, that engine is highly undercarbed as you would expect. We'll see if dual ignitors helps with the emissions and power (his truck reaks of unburned hydrocarbons compared to both mine and my friend's engine(s)).

RX-Midget

Felix,

When my MSD died, I called Autotronic Controls Corp (makers of MSD) Tech line at 915-855-7123. They said they could fix it, and their max charge was about $50 no matter how bad the unit was. I sent my old (~12years old) 6A and they fixed it for $19 including shipping. It did take about 3 weeks though.

BTW - I also told them to "update" it, so they swaped out some of the older parts for newer ones.

madaz07

Jeff20B this is madaz07's friend please read the text below that i have pasted in from an email that i sent to an auto electrician friend who said he wouldn't recommend your direct fire diagram because one leading plug would fire at TDC and one during compression (something like that)

i don't think it would work, both leading ignitors would recieve the same signal and send it to the coils and then to the both leading plugs at the same time, direct fire but at the same time

the rotor button determines when to fire (firing order)

yes you can put the trailing coil lead to leading position on the cap and change the plug leads on the cap from trailing to leading and it cuts out one air gap because it then uses the carbon button but a lot of good that is if you don't have a firing order on the leading plug leads

please don't take this the wrong way but if you bypass the rotor button which sort of tells the leading plugs when to fire yes it will run but for how long before the big bang

are the leading plugs firing at the same time using your idea????

Felix Wankel

All direct fire setups fire both leading plugs at once. Thats why it is called a "wasted spark" setup. I have two coils, one for each leading plug, firing simultaneously. My car didn't blow up.

Jeff20B

iTrader: (13)

Is your auto electrician friend a rotary mechanic? Just curious.

> the big bang <

Heh. I no longer get big bangs out of my exhaust.

Firing order is somewhat of a joke. The spark can and will go into adjacent contacts in the cap. Yes, firing order is determined by which contact is closest to the rotor as the spark is triggered to fire, but I can rest assured that my Leading plugs will never fire with a Trailing spark.

Do you know why the '80-'85 caps are taller than the points ones? Because of cross firing with the more powerful electronic ignition sparks.

Yep, both Leading plugs fire at the same time.

REVHED

There is absolutely NOTHING wrong in firing the leading plugs at the same time (wasted spark). In fact this is how the 2nd gens came out of the factory.

Northern 7

iTrader: (3)

Has any one out there (other than Jeff20B) that has run both MSD and the duel igniter set ups. No offence Jeff, but you mentioned you were having carb troubles and your case might not be the best case study. I have no problem hitting red line+ at will

I'd like to know once and for all which of these set up's is not only the better performance mod, but which is the best for gas milage and overall dependability. I'm running MSD direct fire now and it's great - but I hate to think I'm missing out on something that's better. I'd try it but I'm short an igniter and they are hard to come buy in my area (new ones cost a fortune) - that's part of the reason I went MSD.

Anyone?

Jeff20B

iTrader: (13)

None taken. Infact, my friend's engine used to only run with power up to 6500 and could barely hit 7k. Now with dual Leading ignitors he has power up past 8k! No offense, but can you get past 8k with your MSD(is redline 8k on your tach?)? Some people say they can, but power drops off significantly on the dyno. The thing about my friend's engine and 8k is simply a bonus because he wasn't expecting anything above 7k to begin with. He also gets misfires from the bad dizzy he's still using and his engine was previously carbon locked and has never had an ATF/MMO treatment.

My gas mileage seems better than before. I'll need to ask my friend how his gas mileage is after he's burned through a tank or two.

Anyone else tried several different ignition systems?

Northern 7

iTrader: (3)

20B

I'm not really interested in hitting 8k - what I want is to hit 7 k quicker! I don't race this car - just something to intimidate the Honda's. You're friend's car sounds like he's getting the benefit out of the 2 ignitor set up, however, he was having problems hitting 6.5 according to your note (dizzy problems?) and may not be the best case to make the comp - I hit 7 without any problem and don't want to go much higher (stock clutch / seals /diff) may take the brunt of the high rpm's and I don't want to replace my engine or drive train. If I can get my hands on another ignitor, I'll give it a shot but the local bone yard 7's have been picked clean (ignitors are the first to go)

Thanks for the info, Jeff210B - I'll be keeping an eye on this thread ...
Someone out there must have tried both as a mod on a car that was running well - I'll really want to hear more about this

madaz07

hey REVHED what sort of HP are you getting from your engine, does the direct fire system make a big difference on your engine. What brand of H/D clutch are you using and how much did it cost,
what type of radiator are you running a 2 or 3 core.
Because im going to bridge port my engine soon.