Again, it's just more opinions, with no facts or data to back it up.


I give up. I've tried to have a technical discussion here, and all I get is shadetree mechanic opinions and old wive's tales.

 

no worries

I'm not your buddy so what he did is irrelevant



you won't EVER see that

shadetree ?
I did it professionally for years on prodution cars and still get paid to build/work on race cars

so in your infinite wisdom you are going to say coils add HP ?
you have data ?
show us a dyno pull where coils MAKE HP

 

lol!

 

I was laughing too

 

I talked to My Dad who has a Degree From Wyo-Tech. Told me that the coil is the LAZIEST Piece in the entire ignition system and the only way a coil will make any difference in power is if you are going to install a Multiple Spark Ignition Module.

Then he told me that if you want to see dyno gains Max your spark plug gap. Probly wont last long on a street car but if you have a DRAG Queen theres some power to be had.

 

Go back and re-read post #47.

I'm getting the strong impression that reading comprehension skills were not a requisite for graduating from auto tech school.

 

someone needs to do an A-B-A test. Then we will know for sure.

I would love to do this on my 440 high compression stroker.

FYI-Accel also sells truck coils. From their description seems like they are modified truck coils.

 

And that's where a stronger coil can be beneficial too, you could run more gap.


Not sure if any of you watched this video, it's a little long at 19 mins, but it's pretty cool, especially the last couple minutes of it, where they have the truck coil firing a plug gapped at .130" at high RPM. Watching the difference in spark intensity as he changes dwell is interesting as well. (seems to contradict what thetaxman claims).
http://video.google.com/videoplay?do...65754251&hl=en

Of course that is in free air...the compressed charge in the cylinder isn't quite as kind to promoting ignition.

 

exactly

 

So varying spark intensity is only possible in free air, but isn't in the combustion chamber?

 

Not necessarily. The electricity will take the path of least resistance. Once resistance across the gap becomes greater than the resistance of traveling down deposits on the insulator to ground, guess what happens?

 

the combustion pressure determines the spark
if that has changed let me knoiw
like I said , auto tech was 25+ years ago

bad coils cost hp
a good coil will not add any

 

Absolutely agree with that.

I'm not saying gap your plugs to 1/8" and reap the benefits...but with stronger spark (which is heavily dependent on the coil), running a bit more gap is certainly feasible.

 

I'm disappointed. You stated it correctly before, and now you stated it wrong.

Can't you at least be consistent?

 

Saw that Video and wondered if anyone would comment on it here.
Seemed pretty interesting to me. I would say that using the truck coil wouldn't be a bad thing, and seems like it would be more cost effective than some of these high priced after market coils.

Wonder if they would be strong enough to run a consitant gap on a plug like this.........
Those make a nice ball of fire on them

 

Well, not really. The gap will always have a greater resistance. By definition, the gap resistance is infinite. The insulator resistance, however, will vary from infinite on down to a few hundred thousand ohms (ballpark numbers), depending on the level of fouling.
The "soot" and deposits on the plug insulator are obviously resistive shorts across the gap. During the (reasonably short) time that it takes the coil to raise the secondary voltage to arcover level, the plug soot is leaching coil energy to ground. The more energy stored in the coil, the more that is left (after the leaching and after the gap arc starts) to be imparted into the air-fuel mixture. That's a key element in the old High Energy Ignition system. (Note that it was not labeled High Voltage Ignition.) Any old system will create a high enough voltage to arc the plug gap in new plugs. It is the extra energy, not voltage, in newer systems that allow the engine to keep running for miles and miles after the plugs have fouled or worn to the point where an old points system would allow misfires due to insufficient energy being imparted into the air-fuel mixture.

 

Are secondary voltage rise time, and total energy both factors then? Can rise time be controlled? For example, are points a less "instant" switch, affecting rise time?

 

Im willing to do some testing. Just need to find some coils that wont cost an arm and a leg.

BC

 

You are correct on every point here. May I (in all honesty) say how impressed I am with the depth of your thoughts on this.

Now, to your questions/statements:

Due to fouling in the plug insulators, dirt/contaminants/humidity on the coil surface, and simple capacitance between the plug wire and any nearby metallic surfaces, there are numerous places that are trying their best to bleed off the energy stored in the coil (at the moment of intended spark. ie: end of dwell). A little extra energy stored in the coil compensates for these losses. Now, the quicker that we can get the coil secondary voltage to jump from "essentially nothing" and on up to the 10-30 kV point needed to arc over the plug, the less time there is for this energy to bleed away (in the form of small currents). Good coil design, with minimal internal capacitance, allows a faster risetime. Also, thanks to modern electronics, we can switch the coil primary current off damn quickly. This fast switching has several advantages in efficiency, allowing the coil to not only produce a higher voltage (if needed), but a quicker risetime. A limitation to the old points system was the points cam, compared to power transistors, just slowly and gradually opened up the electrical connection, and the condenser, while doing a remarkable job of protecting the points, gave a side effect of slowing the shutoff of the primary current. Slower shutoff means less efficiency and less available kV at the secondary. (There's formulas for this if anyone is looking for cures for their insomnia. ) Modern electronic modules don't use (or need) a condenser on the power transistor that controls the primary current. The elimination of the capacitance (the condenser), and the great speed that the transistor switches (compared to the points opening) allows greater speed and efficiencies in transferring the energy from the coil to the plug gap.

 

Called Lingenfelter Today and spoke to Jason he said there ARE no GAINS from Changing coils unless your old coils are bad. I think i will take the word of someone who builds Race CARS and has Engineering Degrees.

If you want to know call them. They have done the test on an engine dyno. BACK - BACK.

260-752-2552 ASK for Kevin or Jason