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Coils: More is Better ? Always ?

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Old 01-07-05 | 12:13 AM
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Coils: More is Better ? Always ?

So if the stock coils are 35,000 volts, and Blasters are 40,000... why not use the even higher vette coils or even the following 60,000 volt oil filled chrome coils ?


http://www.engineworksperformance.com/images/ew%20catalog04-63.pdf#search='coils%2060,000%20volts'



My question is are higher voltage coils better and is there such a thing as too much ? What would it hurt ?
Old 01-07-05 | 12:15 AM
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copy link to your address line and go sorry
Old 01-07-05 | 12:22 AM
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you sure stock coils are 35k and MSD blaster 2 are 40k??
Old 01-07-05 | 12:45 AM
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No, I said "if". Not the point of the question at all. OKAY, say they're 40,000 and 45,000 if you prefer. My question is still whether 60,000 is better than the blasters or the stock coils ?
Old 01-07-05 | 12:55 AM
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i think someone here has to try it and give us results
Old 01-07-05 | 01:01 AM
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What I'm hoping. I am confused a bit about this. When I go DLIDFIS in the Spring, I am probably going with HEI ignitors. Should they be the higher output ignitors with the matching 60,000 volt coils while I'm buying parts ? Jeff or somebody probably knows and/or maybe has experimented.
Old 01-07-05 | 01:05 AM
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where else are those 60k oil filled coils available? i think i might have to give it a shot if no one else does.
Old 01-07-05 | 01:37 AM
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JC Whitney LOL

60,000-volt High-performance Ignition Coil Read more
Item: 81ZX1960W

Price: $26.95 with attached bracket
Old 01-07-05 | 01:46 AM
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man wtf... blaster 2 coils cost like $45 on average. that price is a steal. i will have to check to JCwhitney then. thanks grimes
Old 01-07-05 | 02:42 PM
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bump for whoever might have input
Old 01-07-05 | 04:01 PM
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Oh, ok then. The voltage the plug sees only needs to go as high as what is required to jump the gap. The rest of the engergy is put into the duration of the spark. Spark duration on a rotary is more important than actualy voltage due tot he rotary's long combustion chamber.

I've said it before and I'll say it again. If you can afford to get expensive aftermarket ignition components, then go right ahead. Otherwise, you can stick with stock stuff.

I've just tested a J-109 and Diamond coil to 20k RPM with a simulated trigger with one spark per rev. That translates to 10k on a rotary where 2 sparks per rev at 10k equals 1 spark per rev at 20k. Yeah, stock stuff is adequate.
Old 01-07-05 | 05:18 PM
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Originally Posted by d0 Luck
man wtf... blaster 2 coils cost like $45 on average. that price is a steal. i will have to check to JCwhitney then. thanks grimes
Where are you getting your rapeage prices from??

MSD Blaster 2 coils are 30 bucks from summit racing
Old 01-07-05 | 05:29 PM
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I Still like my FC coil set-up..

it packages real nice.
has been really reliable, and was cheaper than event he JC whitney coils.

In order to take advantage of the longer duration of those coild you would need something to control it, like the MSD... which will help stretch the spark duration.
Is my thinking correct on this?
Old 01-07-05 | 05:57 PM
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Originally Posted by hornbm
Where are you getting your rapeage prices from??

MSD Blaster 2 coils are 30 bucks from summit racing
Summit Racing is where I get my Blaster 2 coils from. And Carter fuel pump. And Holley FPR.
Old 01-07-05 | 06:06 PM
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Im runing 4 Boush coils.
Attached Thumbnails Coils: More is Better ?  Always ?-416517_147.jpg  
Old 01-07-05 | 07:28 PM
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Originally Posted by Jeff20B
The voltage the plug sees only needs to go as high as what is required to jump the gap.
Is it known what voltage is required to jump the gap ?

Originally Posted by Jeff20B
The rest of the engergy is put into the duration of the spark. Spark duration on a rotary is more important than actualy voltage due tot he rotary's long combustion chamber.
So then more is better ( but not necessary ) ?
Old 01-07-05 | 08:14 PM
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I don't know the exact amount but it varies with AF mixture and compression ratio. A few thousand. Forced induction and exotic fuels require a 'hotter' spark.

Yeah, more is better, but not totally necessary. If the ignitor/coil combo draws around 3 amps, it's good enough.
Old 01-08-05 | 01:38 PM
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Originally Posted by Jeff20B
I've just tested a J-109 and Diamond coil to 20k RPM with a simulated trigger with one spark per rev. That translates to 10k on a rotary where 2 sparks per rev at 10k equals 1 spark per rev at 20k. Yeah, stock stuff is adequate.
Did you measure the spark output? The question is, how much coil saturation are you getting at such high frequencies.

That's one thing I really like about the MSD... there's no waiting for the coil to saturate, since capacitative discharge ignitions use the coil as a step-up transformer instead of a storage device.
Old 01-08-05 | 03:23 PM
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I haven't tested that yet. I was more interested in the dwell duty cycle than anything else. If I get back into testing it at high RPM, I'll let you know.
Old 01-08-05 | 05:25 PM
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Most electronic ignition modules have nearly 100% dwell. That's the secondary performance advantage of electronic ignition over points - the main being that you can run full voltage to the coil since you don't have to worry about burning the points up.

Actually, they're about equally important.
Old 01-08-05 | 05:59 PM
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The MS has a dwell duty cycle preset from 50% to 75% and it's also user adjustable. When changing the duty cycle, I can see and hear differences in the spark at the spark plug and Diamond coil with J-109 I'm bench testing. It seems 50% works better than 75%, but the spark is only jumping a small gap and I have no scientific way to test it. The problem I had with 75% duty cycle was that it would heat the coil and ignitor a lot at low RPM (it had more than enough time to saturate the coil resulting in heating of the components) and 50% seemed to be a happy medium at all RsPM so far.

Actual testing on an engine is needed to be sure of which duty cycle I should use. As for high RPM use, the coil didn't get as hot as it did at low RPM. I assume it's because it had less time to saturate. Anyway, it's currently set to single spark mode because that's the only thing available. With late leading (two sparks per rev) the coil will heat up less.

It's kinda funny; the MS was originally a fuel-only aftermarket ECU and now it's got three ignition channels capable of firing a 20B or V6 (my testing will prove if this is actually true or not) without the need for EDIS or other outside-the-box-components (aside from ignitors and coils) or funny multi-tooth wheels. Actually it's now up to four channels, but I don't need the 4th one.

Last edited by Jeff20B; 01-08-05 at 06:02 PM.
Old 01-09-05 | 12:52 AM
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Jeff,

Surely James will put a charge time factor in there? Running a fixed duty cycle eliminates one of the big advantages of an electronic ignition. Short duty cycle keeps the coil cool at idle, but provides weak spark at high rpm. Hight duty cycle gives good high rpm performance, but cooks the coil at a stoplight. If it's possible, I'm sure James and Phil will get it done.

I'd exercise a bit of caution in bragging about the capabilities of the system until it's be thoroughly tested and debugged. That last thing we need is a bunch of people arriving at the MS forum expecting a $200 plug-n-play standalones.

As far as EDIS goes, consider it 2 (or 3 or 4...) smart ignitors in a single package with integral crank triggering capability. More than one way to skin a cat, pros and cons to each. Keep up the good work with the CAS stuff, though, as it has potential as well.
Old 01-09-05 | 05:47 AM
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whats MS and where is the forum?
Old 01-09-05 | 10:30 AM
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DAVID GRIMES:

I will go out on a limb and say in my opinion More Voltage is better when comparing coils ! ! !
Old 01-09-05 | 02:39 PM
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the larger the gap at the plug the more voltage is required to jump the gap. So if you've got a big gap you'd benifit from more voltage cause it's require more to make the jump. Then the spark would be physically bigger... shorter duration, but physically larger spark..



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