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In my experience there is no need to update or improve factory ignition systems. Look on older engines you'll find people updating them to the same coil on plug technology. You have plenty of spark energy now, more than enough for 500-600-700 hp.

Maybe if you were trying to hit 900-1000 hp and need to light very dense air you might need to change but since 0% of the ST community is near that threshold and less than 2% are at the 500 hp level; there no reason to even suggest or even investigate something like this.

If you somehow damage a coil then fine, they are likely cheaper than the OE part, but for performance gains = zero
 

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So four things if I may:

First, MSD makes an emission-legal coil-on-plug unit for our cars, unlike the Accel units which don't have a CARB exemption:
https://msdperformance.com/products/coils/ford_ecoboost_coils/parts/82594

Second, it looks like my 2013 ST gets to use the exact same coil-on-plug unit that (at least based on the two VINs I used to look them up) that my daughter's 2012 Focus SE uses.

Third, quoting from the AEM web site:
"Any enthusiast running boost, nitrous or high RPMs is aware of the trade-offs associated with inductive coils versus converting to a capacitive-type discharge ignition system (CDI). The typical argument is that inductive coils deliver a long spark duration with simplicity, but not enough energy to light off the combustion chamber of a modified high-performance vehicle. In contrast, CDIs deliver intense energy but with practically no spark duration, making the proper mixture in the combustion chamber critical for best performance. This tradeoff ends with AEM’s High-Output Inductive Coils, the first inductive coils that deliver CDI-like spark energy and voltage, and the long spark duration necessary for vehicles running forced induction and nitrous."

Fourth, we know that for a given coil the spark voltage is determined mostly by the spark plug gap. Is it a coincidence that most tuners recommend a gap on the smaller end of the scale? You'd think that you would want biggest, badass spark you could get to get the most complete combustion possible -- especially at higher rpms. But lots have posted that they have found that we get knock and other issues at higher rpms with plugs gapped "too wide". My own experience with my built rally car turbo motor was that once we went to a proper MSD ignition, we got better results opening up the plugs to 0.034", because that enabled the MSD ignition to produce a higher-voltage spark (and the MSD ignition had the capacity to do so). And that in turn enabled us to run ridiculously cold plugs that would otherwise have fouled at idle, but which were perfect on a special stage.

The Accel website seems to claim their coils deliver something like 10%-15% more energy than stock coils, so if our STs are using the same coils originally designed for normally aspirated motors, for a tuned ST it might be cheap insurance at higher rpms to run with one of these aftermarket, higher-output coils. Possibly more so for a car fitted with WMI, as my understanding is that WMI (and indeed all higher octane fuels) slow down flame front propagation, so best to have the most vicious killer spark kicking things off you can, yes?

Some tech background sources FWIW:
http://sdsefi.com/techcomb.htm
https://www.physicsforums.com/threads/combustion-of-gasoline.720348/

Would be interesting if someone ordered a set of these coils, and at the same time opened up their plug gap to 0.030"...

Hope that helps,
Mark
 

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First, MSD makes an emission-legal coil-on-plug unit for our cars, unlike the Accel units which don't have a CARB exemption:
https://msdperformance.com/products...d to see what tuners have to say about these.
 

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No one should care whether it is CARB legal or not. Breathing wrong is illegal in commiefornia.


I'm interested to see what tuners have to say about these.
I too am interested in what the tuners say, so I posted in the Stratified forum. If you have a favorite tuner please feel free to post in their forum(s) here as well. The more technical opinions we get from other tuners, the better.

As the OP, I would be grateful please if we could keep this thread centered on the technical aspects of OEM vs. non-OEM coil packs, and leave the CARB-approved (or not) aspect to a different thread if you wouldn't mind.

S'OK?

Thanks,
Mark
 

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Discussion Starter · #9 ·
I too am interested in what the tuners say, so I posted in the Stratified forum. If you have a favorite tuner please feel free to post in their forum(s) here as well. The more technical opinions we get from other tuners, the better.

As the OP, I would be grateful please if we could keep this thread centered on the technical aspects of OEM vs. non-OEM coil packs, and leave the CARB-approved (or not) aspect to a different thread if you wouldn't mind.

S'OK?

Thanks,
Mark

I looped Unleashed into the discussion you posted on Stratified's sub forum. Torrie's pretty good with answering so hopefully he'll chime in soon.
 

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Why would you need tuner input?

Where has it been reported of spark blow out around here?

As I said it MIGHT happen if you were considering a turbo of about 70 mm but none of you are, why? Too much concern over spool delay/lag/etc.

At stock-ish levels (max duty cycle) you will gain NO ADVANTAGE with aftermarket coils. People thought there would be a benefit to upgrading to the MSD coils over the OE coils from Mopar (Neon SRT-4).

What they got was spark issues from inconsistent voltage.

As I said don't fix what isn't broken.
 
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