BDC

YES it works!!!

I just spent the last 8 hours hacking up hardware and re-doing wiring (some of which was nearly 10 years old) in a pursuit to test an idea I came up with several days ago. It popped in my head the day after a very late night of several hours of food poisoning symptoms. I'd been toiling over how to achieve sequential lead ignition for several days prior on my own car without the potential of having to ditch the older E6K.

Claudio, this is why I was bothering you about the Auxiliary Out 5V lead on the Haltech. I confirmed my suspicion about how it worked after spending a good while going over hold HaltechSupport Yahoo group messages plus, after posing a question about it, based on the response I received from a gentleman who'd put it on his oscilloscope in the past. He responded by saying that the 5V out, when set to Ignition Toggle in the Input/Output software, goes 5V up for 180* of crank rotation then 0V for the other half. He said it's a square wave. I'm not sure exactly when it starts but I'm assuming it's based on when the ECU receives Home signal from the trigger. For those not familiar, the Auxout 5V lead is the 'toggle' lead for the 2nd gen trailing ignitor. From what I've learned in my research in all this, apparently this trailing ignitor is an oddity in the ignition world as it acts as a dual ignitor with an input. When this 5V input is up, it fires one coil. When it's not, it fires the other coil. This is how the 2nd gen achieves sequential trailing ignition from the factory and via the Haltech.

The sheer simplicity of the idea made me beg the question, "why hasn't anyone does this?" If anyone has, only few in the community would probably know about it. I think it's because it's got no demand from the folks in the community due to the largely unknown discussion of the differences between sequential and waste spark and namely waste spark's potential for severe problems when under high loads. The fact that several high-horsepower folks and some of those in the racing community advocate sequential ignition is what drove me to researching this.

For those unfamiliar with the components and setup, both the 2nd gen and 3rd gen from the factory run sequential spark on the trailings with waste spark on the leadings. For both 2nd and 3rd gen, the leading setup is one ignitor with a dual-post coil (two outputs on a single coil) that is triggered twice per full crank rotation or every 60* a rotor in a chamber turns. That means that when a front rotor is at TDC (rotor face flat up against spark plugs) and is scheduled to fire a lead plug for example, the back rotor chamber receives a spark as well even though it's position is at BDC (rotor apex tip just before/at lead plug). The trailing differs a bit between the 2nd and 3rd gen, but the practical, end effect is the trailing plugs are fired in sequence; they run independent coils for each trailing plug and are fired in a direct-fire type setup either with their own independent ignition channels (3rd gen) or by a waste-spark pulse sent to a trailing ignitor w/ a 5V toggle lead. There is no double-firing of trailing plugs as is the case with leadings from the factory.

As mentioned already, what I basically did was take a spare 2nd gen trailing ignitor/coil pack, do some hardware modifications to better mount it in the factory location in the 2nd gen, parse off of the Haltech's Auxout 5V (green/black) toggle lead, and sent it to this additional trailing ignitor. The only difference between both trailing ignitors in this case is the signal (pink) lead -- the original trailing ignitor still retains the Digout (White/black) for coil signal where the additional trailing ignitor, now working to fire the leading plugs, takes the same IGNOUT (light green) signal to go to Pink. From there, the Auxout 5V toggle lead is sent to both switching ignitors and tells them which coil to fire based on crank position -- either front coils or rear coils.

It's so easy and simple and works perfectly. It's simulated direct fire but still using a waste-spark setting in the Haltech to pulse these two switching ignitors twice per crank rotation. No more waste spark. From now on it's important for me to make sure the leading plug wires are on their respective front and rear coils. This is something I highly recommend ALL older Haltech owners w/ 2nd or 3rd gen cars to do to eliminate leading waste spark!

Here's some photos of the hackup and the installation:
http://bdc.cyberosity.com/v/ProjectC...alLeadIgnition

slo

iTrader: (1)

What do you percieve to be the advantage of sequential coil per plug vs waste spark?

Is it an issue with wasted spark in of itself or do you not like the dual post coils?

You say "waste spark's potential for severe problems when under high loads".. What severe problems, specificly are you talking about.

Another setup is to run independant coils of a single input, so its waste spark but does not use a dual post coil.

BDC

This will open a whole can of worms probably better suited for the Rotary Performance section. It's hard to say because I'm still new to it but I can't help but think that there's something potentially bad with having a wasted spark in the adjacent chamber. It also violates one of the basic tuning rules I have even though that rule is more centered towards doing things to avoid knock -- "There should only be one purposefully timed spark event per power stroke." Rhetorically speaking, what happens if there's a misfire or something else to occur to otherwise bring the engine out of smooth power output when load is very high? What happens with unburnt gasses when that rotor swings around towards BDC and then is hit with an unshrouded spark from the lead plug? I don't know but it doesn't seem good. My current theory is that waste spark on the leadings is more of the silent but sure killer of engines than perhaps many of us are considering. Why is it some of the very high power guys are against it?

That's essentially what this is -- still only one ignition channel from the ECU but to two independent coils; a carbon-copy of what was already going on from the factory and done by the Haltech ECU except using the leading ignitor signal instead of the trailing ignitor signal.

B

slo

iTrader: (1)

Then this deserves a new thread in another section if you don't want to talk about it here.

I don't see how a spark fired into the allready combusting exhaust gas is going to cause a problem, even if there is a total misfire and the chamber is full of combustable gas with a rich pocket near the apex seal where it fires, the volume its firing into is expanded, and moving twords further expansion.

The design I am talking about is still a wasted spark and its for a different reason, its the setup people use on 1st gen's to get direct ignition. The 2 coils are being fired simeltaniosly. This is usally done to fire both coils in parallel of a single CDI box, because the box can handle it, and because an ignition box set to the 4cyl setting intended for cars with a distributor willl fire at the same duty cycle as the leading coil does if wasting a spark. And the theory is that there is more spark energy if the spark isn't having to jump 2 gaps.


This is the question I am asking?

BDC

I honestly don't know why folks are against it other than the reason I've cited why I am, Slo. I wish I knew. Call it a hunch for me at this point. Perhaps others who've ventured into this can teach us more about it but as it stands for me right now I'm taking it on faith from a couple of folks who've done this stuff alot longer than I have.

B

C. Ludwig

iTrader: (27)

Whether direct fire or wastespark is THE way to go I'm impressed with your thinking outside the box. This is one of those things that, after the fact, seems so obvious. Good job!

BDC

It seems so obvious yeah but as far as I know only one other person has thought of it and actually done it (fastrotor, Gary Mounsey in AUS) and that was many years ago. It's never been a deal here in the community AFAIK. The funny thing is it came to me while my head was in loopy lala land after being exhausted from being sick the night before; not when I was clear-headed any other time I was thinking about it... :o

Thanks!

B

slo

iTrader: (1)

I can agree with this, it is out of the box thinking.

BTW I do remember that there were other ignitors out of early 90's cars with the same toggle function, not specificly what.

I think the reason is that its an easy way to add a waste spark ign to a 4cyl, that previously had a computer controlled distributor.

jacobcartmill

iTrader: (6)

why did you separate the new primary igniter from the primary coils? space restraints?

BDC

Yep. I couldn't pack it all in there in the same location the factory leading hardware went. Plus it kinda looks cool having the two factory trailing coils side-by-side near the main fuse block.

B

jacobcartmill

iTrader: (6)

i think you should stand them up and put all 4 coils on the block, FD style.

or relocate that big ol battery to the back and put all 4 coils there

BDC

Nah, like my big ol nasty Red Top Optima with ninja power wiring and fuses everywhere right where it is.

I kinda like the look of the two trailing coils where they're at. I doubt I'll move them. I think however I will add more foam to their underside to help keep them from vibrating to death. They've got some weather stripping underneath but I'd feel more comfortable with something beefier.

B

jacobcartmill

iTrader: (6)

looks good mr cain.

hammer

GregW

Not too many folks will understand why this is so damm cool that he sorted this out.

B, you need your own dyno, like 5 employees and an endless supply of rotarys.

Thanks for sharing this stuff with us!

Now comes beta testing......

fritts

iTrader: (5)

I believe the benefits of this would be that you can charge the coils to twice the dwell time as you could before. Not sure if this will help on the stock coils but on an aftermarket coils that takes longer to charge you would now have more spark energy.

moremazda

iTrader: (4)

This seems to be the true benefit of the sequential spark setup. Although probably more applicable to a naturally aspirated motor in terms of power output since the wasted spark setup is better suited to raising exhaust gas temperatures rather than aiding in the increase of cylinder pressure (either peak pressure or the rate at which peak pressure is attained).

fritts

iTrader: (5)

I would say the opposite in that the forced induction guys usually max out their ignitions sooner than the NA guys. Though I haven't messed with many high output NA's.

Either way this is great stuff.

BDC

Update. Drove it today. Drove perfectly fine without a hitch anywhere. Even boosted it; no issues. It's almost like nothing was ever changed. For those that are interested in doing it, I say "thumbs up" and go for it.

B

slo

iTrader: (1)

I think he is saying that its because modified NA engines typicly spin faster to make power.

You can't use twice the charge time up till after 7 or 8k RPM, because you can only charge the coils so much before they overheat. The lower DC should put less stress on them however.

Of course this doesn't apply if using a CDI, they will charge the coils a great deal faster, which is how they are able to acomplish multiple sparks per revolution.

Claudio RX-7

iTrader: (1)

Wow! What a great idea this is. It makes me wonder about a few other things too. Why didnt I think of this one!

Great work Brian!

BDC

Thanks! Yep it was stupid simple but isn't it always the stupid simple stuff that people never think of?

B

Slammedblk7

iTrader: (7)

Looks like I have to add this to the list also!

a_reyes1014

iTrader: (1)

so bdc, you just took the same toggle wire for the actual trailing coilpacks and share it with the leading trailing coil ignitor?

BDC

Correct. All I did was duplicate the trailing ignitor hardware and setup with the exception of the change of one wire. The additional (trailing) ignitor that's now on the leading side still has the IGN 1 out channel going to it like it did originally going to the factory leading ignitor.

B

a_reyes1014

iTrader: (1)

so this should work with pretty much any aftermarket ecu. i will be installing my megasquirt as soon as the harness comes in and i have a spare trailing coil pack w/ignitor laying around so im going to give this a try. that is pretty simple and should have its advantages like you stated in the above posts.