What if the first spark failed to ignite the fuel? Multiple spark will guarantee ignition. What if at 5500 rpm the spark failed to ignite the fuel? A stronger spark will insure ignition.

Regards

Jean Marc Chartier

PS the Ford Triton ignition use multiple discharge spark.

 

Flagship, Respectfully, I probably have as much age as you and been in the technical fields for most my standup life.
What your summation of plugs is is a natural acumulation of 'surface' observation as is most other peoples.
You know Ford and other makes have progressed with ignition from single coil to two pack in either 4,6, 8, and 10 cylinder versions and now to single coil per each cylinder for technical reasons which should not be dimissed. It's those tech reasons that don't get aired, that become the reasons for concluding these advances don't offer any advantages.
Yes the cost goes up for those technical advances, but the mfgers are evaluating these as time goes by, with testing for the cleaner burn, reliability and cost factors and bring them on as the needs arise. But some of this rasies the price in a competitive market place and becomes a marketing decision if not an emmissions decision per the design of the individual motors.
I could write a small book here on ignition and multi spark, plug tip design and flame kernal actions in the cylinder but not sure how much of it would be appreciated on this board, with the present level of thinking.
To close, we run Ford powered sprint cars and I assure you we and no other car owners run a single coil on a 'common ignition' without the uses of an ignition amplifier such as MSD or Crane, high quality distributor parts and wires as well as change the plugs at short intervals.
So far these box designs cannot offer more than a single spark above 3000 rpm so that feature is not usefull on a motor that runs WOT rpm of 4500 to 7800 but is very usefull for starting and low speed running on any motor.
I would beg of you to not dismiss performance from these parts and operational procedures without learning the theroy behind there attributes and when there uses have value.
Thanks.

 

Wouldn't the "charging" of the capacitor affect timing to some degree?? I realize it would probably only be ms.,, but still?

EDIT: duh, ok sorry, I should'a read more before posting.
Good info http://www.pulstarplug.com/howtheywork.html

 

Yes but to a very very small degree.
You must take into account at least some of the following.
1. The signal transit time from the moment the PCM applies voltage to the coil.
2. The coils rise time to core saturation. (it's not simply a stepup tranformer).
3. The coil's magnetic collaspe time. (hysteresis involved)
4. The charging of the 'inherent' capacity that exists with the plug's relationship to the walls of the head well it sets in.
5. The mixtire condition that dictates the amount of voltage needed for gap breakdown also influences the charge time.
6. Any other leakage and loss conditions less then perfect that contribute to the end result.
The capacity hats these new plugs use is in the order of 80 to 100 pf. Not very high as capacity goes. Then they only get to charge up to the point the plug is able to break over the gap.
Going further, there is a circuit constant known as 'time constant' that is considered the time it takes to charge a capacitor to 63.2% of it's max.
This is because the charge takes place on an Exponential basis and keeps taking longer and longer to fully charge to max from it's supply as it nears max.
Your question are fine but be awhere there are a lot of different parts of these circuits to put togather for a full understanding. That means we can't say just one thing about it and have that be all there is.
Then add in repetition rate that as rpm goes up there is less and less time for some of these actions to complete until the time comes for the next advancment in the system to be used. This is why we are now at the COP stage. The old systems could not keep up with certain requirements.
Ford knew this as far back as the mid 90s when COP began and way before that with various other sytem configurations like dual plugs, waisted spark etc that all can't live up to todays requirments being that of regulation for emmissions.
Back to your question:
Plug breakdown point constantly changes over a small range so that in it'self constitutes a small timing change as to when the kernal begins the expansion push on the piston. It's fractions of a micro second but it is a change that can be disreguarded until it begins to get long enough to affect cylinder power in a measurable way and combustion completness.
This has an extended explanation all it's own.
Adding some capacity at the plug won't change this to any significant degree as opposed to the value the capacity has in dumping it's stored voltage accross the plug gap as the real gain this type of plug is intended to have.
Granted, to make full use of this design, a total circuit optimization must be done. Using these devices on a secondary application basis may or may not show worthwhile gains in some motor designs.
Lastly the driving force behind this is that the present day ignition systems are usually less than one percent efficient in converting the coils 12 volt drive signal to energy at the plug gap. The effort being made for the future is to get into the 10% plus range by reduceing losses, improving circuit and parts design.
Example this; at a coil drive of 13 volts, the usual coil current is in the order of about 4 amps +/-. That equals 13 x 4 = 52 watts of power. The plug gap never see this much power in the gap to help combustion so where has it gone? Waited as heat in the distributes circuit losses. If a plug's breakdown voltage were at 8000 volts, a current of .0065 amp woud be requires to equal the primary power at 100% conversion but we know that were less than 1%, so there is lots of room for improvments.
Looking back to the above 8000 volts; if we can get the stored power of the cap to deliver even half it's stored energy, we could begin to see instant powers in the gap of say as much as 1/4 amp. That translates to instant powers of like 2000 watts instant peaks. You may say wait! how can that be? It's based on the anount of electron charge stored OVER a TIME peroid and not what just came from the coil for a short time, pulse.
Sorry it gets complicated.

 

well i got the pulsar plugs in the mail today....so when the weather gets warmer in a few weeks they are going on and i can let everyone know what i think.

 

Any updates??

 

Through further investigation, I came upon this:

And from GoFastNews.com:

So in other words, they help the most with ignition systems that are of lower quality... We may not see much of a gain with our COP's which already have quite the hot spark to begin with.