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Coil on plug question

you are over simplifying it and are off base here. Using a COP module in a waste spark system is not ideal. If you wire it in series, as others have done, it will work and you most likely will experience no problems. The issue with this is that in series you are cutting the voltage to each COP module. In addition, you are messing with the dwell time. I dont know the specifics of each system, but think of it this way, on a system designed for COP, you have 6 injector drivers in the ECU, each one controlling a COP. Each coil on plug requires a specific voltage and a specific dwell. If you wire 2 COP in series for one driver, you are cutting the voltage, and since you are firing one in waste spark, you may not have the appropriate dwell time. The bottom line, though, is that I have not been able to find any of the specifics for either system, there really is no way to accurate determine how much you have cut your spark output, but I can assure you that you have.

You can try wiring them in parallel, but I think you will be looking for a new ECU. Once again, you are missing the point here. It is not power draw you are worried about, it is current flow. It is a simple OHM's law equation. Wiring them in Parallel will cut the resistance in half, which will double the current flow. Yes, you are correct that the coil has voltage source in fuse box, but it is being grounded by the PCM, the current still will flow through the drivers and burn them out. Think of it this way, the fuse for the ignition system is ONE fuse for the entire system, you are only firing 2 Cylinders at a time, you can have enough current to fry a driver without popping a fuse.
IDK if you are right but like i said no one has lost any power and no one has had any issues with frying a ecu. And if the ecu is sending enough voltage to fire 2 cylinder from the coil pack then maybe its enough for 2 coil packs
 
IDK if you are right but like i said no one has lost any power and no one has had any issues with frying a ecu. And if the ecu is sending enough voltage to fire 2 cylinder from the coil pack then maybe its enough for 2 coil packs

based on your response, i am guessing you didnt read what i wrote for a couple reasons.

1. i said people had them installed and running with no issues, but they are all in series. Like I said, it may work just fine, but OHM's law proves your spark output is not as high as it is with the coil pack, its not my opinion, its how the math works. circuits in series have voltage drops with each component (COP). People have had issues, too, not everyone has had no problem. especially with forced induction, i bet a turbo engine will blow that spark out.

2. The ECU does not "send voltage", the ignition drivers are negative triggers, meaning they ground the circuit to charge and fire the coils. its not "sending voltage to fire 2 cylinders". once again, ohms law- with the coil pack, the coil fires 2 cylinders, the voltage is whatever the voltage of the circuit is. The current will be dictated by the impedence of the coil within the coil pack. With 2 COP modules in parallel, yes, you still are firing 2 cylinders at the same time, and the voltage of the circuit is still the same, the difference is you are halving the resistance by wiring them in parallel, which means you are doubling the current- it has nothing to do with the amount of cylinders in the circuit, and everything to do with the current flow within the circuit. since the ECU is grounding the circuit, it will see this excess current. I dont know for sure if it will fry the drivers, but from my research it looks like it will.
 
So the problem is with the PCM/ECM taking the current when it grounds the coils... what if we only used the PCM/ECM to send the ground signal, but rather direct the grounding through another circuit that could handle the current... I might have to run some of this by my ex-Honda electrical engineer coworker and see what he has to say about this. I'll get back to you guys tomorrow.

EDIT: I'm no electrical engineer (I'm mechanical), but after some searching around on the web, I wonder if we could use some high current solid state relays in combination with the ECM to take the load. They should be able to handle the rapid cycle times I think. Someone correct me if I'm wrong...

EDIT2: Alright thinking out loud... max rpm worst case any of our engines could see (most likely not) say is 8,000rpm. So the coil would be firing at 133.33Hz. So we would need 3 12VDC solid state relays that can handle whatever current being driven and be capable of handling a switching frequency of at least 133.33Hz.
 
Finally this thread is getting on the right path. I have a little document that I've been spending a few spare minutes each night writing about this. Still have a number of things to hit on though.

For those who think it is fine to go COP just because a number of people are running it with "no problems" (perceived that is), then I say go ahead and follow the leader. Just do it! Let's just say there are also a number of people running Taurus oil pans with "no problems," yet, I would never run one on any of my cars, nor my clients vehicles (even at their request).... but I'll save that debate for another thread! :D

Point is, just because something "works," does not mean it is correct. Can RTV seal up a MTX 75 trans case and keep it from leaking? Sure. Is it correct, not at all. Can RTV create a nice seal underneath Bugzuki plates in a 3L swap? Sure, it will work for a LIMITED time. Is it correct? Not at all!

People do things all the time that are not correct, and some actually do get lucky with no issues for awhile. Just because a number of people are running COP does not mean we should all just "splice and play" COP as well.

Let's just keep this thread on track of COP discussion though. I don't want to stir up anything with my oil pan comments in this thread! :p
 
you are over simplifying it and are off base here. Using a COP module in a waste spark system is not ideal. If you wire it in series, as others have done, it will work and you most likely will experience no problems. The issue with this is that in series you are cutting the voltage to each COP module. In addition, you are messing with the dwell time. I dont know the specifics of each system, but think of it this way, on a system designed for COP, you have 6 injector drivers in the ECU, each one controlling a COP. Each coil on plug requires a specific voltage and a specific dwell. If you wire 2 COP in series for one driver, you are cutting the voltage, and since you are firing one in waste spark, you may not have the appropriate dwell time. The bottom line, though, is that I have not been able to find any of the specifics for either system, there really is no way to accurate determine how much you have cut your spark output, but I can assure you that you have.

You can try wiring them in parallel, but I think you will be looking for a new ECU. Once again, you are missing the point here. It is not power draw you are worried about, it is current flow. It is a simple OHM's law equation. Wiring them in Parallel will cut the resistance in half, which will double the current flow. Yes, you are correct that the coil has voltage source in fuse box, but it is being grounded by the PCM, the current still will flow through the drivers and burn them out. Think of it this way, the fuse for the ignition system is ONE fuse for the entire system, you are only firing 2 Cylinders at a time, you can have enough current to fry a driver without popping a fuse.

Thank you, that's the info I was looking for. I didn't fully understand how it would damage the pcm.

Finally this thread is getting on the right path. I have a little document that I've been spending a few spare minutes each night writing about this. Still have a number of things to hit on though.

For those who think it is fine to go COP just because a number of people are running it with "no problems" (perceived that is), then I say go ahead and follow the leader. Just do it! Let's just say there are also a number of people running Taurus oil pans with "no problems," yet, I would never run one on any of my cars, nor my clients vehicles (even at their request).... but I'll save that debate for another thread! :D

Point is, just because something "works," does not mean it is correct. Can RTV seal up a MTX 75 trans case and keep it from leaking? Sure. Is it correct, not at all. Can RTV create a nice seal underneath Bugzuki plates in a 3L swap? Sure, it will work for a LIMITED time. Is it correct? Not at all!

People do things all the time that are not correct, and some actually do get lucky with no issues for awhile. Just because a number of people are running COP does not mean we should all just "splice and play" COP as well.

Let's just keep this thread on track of COP discussion though. I don't want to stir up anything with my oil pan comments in this thread! :p

This is exactly why I posted what I did, "just because something "works" doesn't mean it's correct". I just want to learn as much about this before I do it, not 10,000 miles from now when I'm trying to diagnose a misfire.

Thanks to everyone for your input.
 
The bottom line, though, is that I have not been able to find any of the specifics for either system, there really is no way to accurate determine how much you have cut your spark output, but I can assure you that you have.
QUOTE]

So youre hypothesis is just a theory. You said it your self you dont know for sure. And someone telling me that it doesnt work ,when people have been using them over a year now with no issues, tells me they are wrong. If someone had a car dynotuned with a regular coil pack and then went back to the dyno with a COP conversion and there was no change in ANYTHING it would mean that its working as it should. If there was a lose in spark there would be a lose in power. And the fool that said he would never use a 3L oil pan on a 3L REALLY must not know what hes talking about lol guess ford got that wrong too. Oh wait its wrong to mod a oil pan by hogging the holes out a little to bolt the 2 bolts in for the tranny i guess. Hell jsut dont do a 3L swap either cause it didnt come in the car. Dont turbo a car neither cause it didnt come from the factory like that. lol wtf DONT USE THE 3L OIL PAN ON THE 3L THAT FORD PUT ON IT FROM THE FACTORY CAUSE ITS WRONG!
 
So youre hypothesis is just a theory. You said it your self you dont know for sure. And someone telling me that it doesnt work ,when people have been using them over a year now with no issues, tells me they are wrong. If someone had a car dynotuned with a regular coil pack and then went back to the dyno with a COP conversion and there was no change in ANYTHING it would mean that its working as it should. If there was a lose in spark there would be a lose in power. And the fool that said he would never use a 3L oil pan on a 3L REALLY must not know what hes talking about lol guess ford got that wrong too. Oh wait its wrong to mod a oil pan by hogging the holes out a little to bolt the 2 bolts in for the tranny i guess. Hell jsut dont do a 3L swap either cause it didnt come in the car. Dont turbo a car neither cause it didnt come from the factory like that. lol wtf DONT USE THE 3L OIL PAN ON THE 3L THAT FORD PUT ON IT FROM THE FACTORY CAUSE ITS WRONG!

can you not read? how about you understand what your talking about first before adding your input?

you don't want to use the taurus/sable oil pan because you have to leave out two transmission bolts. therefore you use the escape pan and then you can install those bolts .... and yes many run the taurus pan and leave the bolts out .... but it isn't right.

and as everyone has been saying, just because it works for some doesn't mean its right and should be done. the guys here are trying to be technically sound and correct before just throwing things together.

what is so hard to understand about that?
 
Point is, just because something "works," does not mean it is correct.
"Correct" is totally subjective. Many people would say anything that didn't come in the car originally, it is not "correct".

Any one person's approval of something is not the determining factor of it's effectiveness.

So youre hypothesis is just a theory. You said it your self you dont know for sure. And someone telling me that it doesnt work ,when people have been using them over a year now with no issues, tells me they are wrong.
Science > semantics
He's not saying it doesn't work... he's trying to explain the science of the scenario.

You're coming across as an ass. I'm not saying that you ARE an ass, I understand that you have good intentions, (I'm a "don't tell me it can't be done" person as well), but you've gone from looking like a reasonable debater, to looking like a non-listening ass. Let's get back to a reasonable debate. :cool:
 
And the fool that said he would never use a 3L oil pan on a 3L REALLY must not know what hes talking about lol guess ford got that wrong too. Oh wait its wrong to mod a oil pan by hogging the holes out a little to bolt the 2 bolts in for the tranny i guess. Hell jsut dont do a 3L swap either cause it didnt come in the car. Dont turbo a car neither cause it didnt come from the factory like that. lol wtf DONT USE THE 3L OIL PAN ON THE 3L THAT FORD PUT ON IT FROM THE FACTORY CAUSE ITS WRONG!

Wow, you really need to learn how to read... and you are so right, I really don't know what I'm talking about. What is a 3L swap anyways? I better look that up. Does somebody have a "how to" for me? :crazy:

Now, you really do sound crazy jumping on the hogging out the bolt hole issue. I never mentioned that being the issue I have with it! Yes, I do have an issue with just not using the bolts because they don't line up, but I don't have any major issue with hogging out the holes and using washers or getting it welded and redrilled. That is NOT my issue with the pan. You just assumed and ranted away. The Taurus oil pan is a fine pan, and it works great in the taurus. Ford got that perfectly correct. A 3L sits in an Escape/Contour with a slight cant different than that in the Taurus. I'm not going to get into the oiling issues and likely dangers with using a Taurus pan in a CONTOUR here, but I never said anything like this regarding the taurus pan in a taurus....
lol wtf DONT USE THE 3L OIL PAN ON THE 3L THAT FORD PUT ON IT FROM THE FACTORY CAUSE ITS WRONG!
The Taurus pan is great in Taurus, but the escape pan belongs on the Contour. Why did Ford design the oil pan differently for the Contour/Escape than the Taurus? For the fun of it? I think not. And we're not talking about the two bolt holes here! If that is all you know about the Taurus pan, or that it is "just a little deeper," than I am truly wasting my time here. I feel like I am debating with a 18yr old who just got out of a high school auto class. wtf lol wtf lol back at you buddy! The information you post sounds like just what you have read from other people on mulitple contour forums.

I'm not against 3L swaps at all. Heck, I've had 28 of my own SVT's and swapped 3L's in almost half of those. I have done even more 3L swaps for clients as well. Maybe I need to say this again for you, I am not against 3L swaps at all. I am just tired of repairing other 3L swaps that people have cut corners on. I am also tired of replacing 3L's that have prematurely spun rod bearings using a Taurus pan. I have yet to have a single build spin a rod bearing, and guess what? I force every single one of my clients to buy an Escape pan/pickup tube. I won't do a swap for a client who wants me to reuse gaskets, use the Taurus oil pan, etc... Somebody else can do those swaps. If someone was trying to do a budget build and still do things right, I would have them use the Contour Oil pan with the updated Escape pickup tube and new gasket. That way you wouldn't be modifying the windage tray and replacing the TTY bolts to make it work with the contour pick up tube.

and as everyone has been saying, just because it works for some doesn't mean its right and should be done. the guys here are trying to be technically sound and correct before just throwing things together.

what is so hard to understand about that?

Thank you Brian. ;)

"Correct" is totally subjective. :cool:

And SicSE, yes, I could've chose a better word. :cool: But subjective or not, many of the Contours I have had to fix have not been "correct" by any means! You wouldn't believe half the stuff I have seen.

I also really appreciate your posts. I have read many of your posts around these parts and you think intelligently. I can tell that you do think about things as well before just following what others have done! And thanks for you good advice helping people out on this forum. :thumbsup:


Now let's keep this thread on topic. I will clear any posts off topic of COP. This thread should be easy to read for those considering COP... not full of debating other issues like oil pans.
 
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I also really appreciate your posts.
Thanks man, and the feeling is mutual. I've learned quite a bit about these cars from your posts. :cool:

Wiring them in Parallel will cut the resistance in half, which will double the current flow.
I understand and agree with everything you've said about wiring them in series, I'm totally on board there. But when you're saying that wiring them in parallel will halve the resistance, isn't that assuming less resitance from an individual COP coil circuit compared to the resistance of a coilpack circuit? Or maybe an assumption of equal voltage multiplication by the COP coil & coilpack? But if the COP coil circuit had the same total resistance as one coil pack circuit, everything would even out right? So to know for sure how this would play out, wouldn't we just need to know the difference in resistance, as well as the degree of voltage multiplication between the COP coil & coilpack circuits? Or am I missing something?

My head hurts.
 
My bad. Maybe i didnt read into it enough. I thought you was talking about the 3L oil pan in general. Maybe instead of making slight comments about the oil pan you should elaborate more so people dont get it confussed
 
My bad. Maybe i didnt read into it enough. I thought you was talking about the 3L oil pan in general. Maybe instead of making slight comments about the oil pan you should elaborate more so people dont get it confussed


topic has been covered before. might want to read up on it more yourself .... I know it has also been covered on FCO a few times ... that and this thread is about COP not oil pans so there isn't a need to go into depth about oil pans in this thread.
 
Thanks man, and the feeling is mutual. I've learned quite a bit about these cars from your posts. :cool:


I understand and agree with everything you've said about wiring them in series, I'm totally on board there. But when you're saying that wiring them in parallel will halve the resistance, isn't that assuming less resitance from an individual COP coil circuit compared to the resistance of a coilpack circuit? Or maybe an assumption of equal voltage multiplication by the COP coil & coilpack? But if the COP coil circuit had the same total resistance as one coil pack circuit, everything would even out right? So to know for sure how this would play out, wouldn't we just need to know the difference in resistance, as well as the degree of voltage multiplication between the COP coil & coilpack circuits? Or am I missing something?

My head hurts.
no. total resistance of a parallel circuit is "smaller than the smallest". if you wanted to replace a parallel set of resistors with 1 resistor that had the same total resistance you calculate it like thi:

Parallel
. 1 . = 1 + 1
Requiv R1 R2

Series (I know you know this but ill put it here for others)
[FONT=&quot]Requiv[/FONT] = [FONT=&quot]R1[/FONT] + [FONT=&quot]R2[/FONT]

now the primary side of a stock coil in the coil pack is supposed to be anywhere from .3 to 1 ohms. since I dont have data on the COP unit I have to assume they are like any other coil and also fall in the same .3-1 ohm range.

as you can see (and which you already agree with), in series the total resistance of the coils now is somewhere between .6 and 2 ohms. this means a decrease in amperage in the circuit, and since each coil is just a step up transformer you now have less power going into each of the 2 coils on the primary side which means less power coming out to the plugs on the secondary side (not to mention the voltage drop that occurs accross any resistor which means that each coil not only is getting less current, but is also only getting about half the voltage as well), thus the loss of spark output (which can be measured using a special machine that hooks up and basically measures the magnetic field around the plug wires to determine power flowing through the wire)

Now, in parallel the the equivalent resistance is somewhere between .15 and .5 ohms which is half of the stock range ( (1/((1/.3) + (1/.3)) = .15) . obviously less resistance means more amperage. this puts the amperage in the circuit up to about 24 to 80 amps assuming just 12 volts. now stock would be between 12 and ~46 amps, however there is a built in resistor in the driver circuit in the PCM which lowers the amperage to a more reasonable level. even with that resistor though, the COP setup in parallel would still be more than the PCM can handle for a long period of time and you would burn out the drivers.
 
good stuff striker, you beat me to it. i tried to track down some info on the COP units when i was looking into with no luck. one other thing to keep in mind is the resistance we are talking about is not as simple as measuring the static resistance of a COP unit with a multimeter. it is more complicated.
i know it sounds like a cliche, but there is a reason cars with COP have individual injector drivers in the pcm.
consider if you do wire them in series as most have done, if one COP goes bad, you will lose 2 cylinders. from what i have seen, COP units go bad more often than coil packs.
 
no. total resistance of a parallel circuit is "smaller than the smallest".
Forgot all about that. I'm either showing my age, or getting old!

one other thing to keep in mind is the resistance we are talking about is not as simple as measuring the static resistance of a COP unit with a multimeter. it is more complicated.
Well, even if it was that simple, it seems like the lowest resistance value in a parallel COP circuit would need to be at least over 20k ohms, (after adding the resistances from a coilpack circuit, you're likely in the teen-thousands). With a possible spark plug resitance of as low as 2k, parallel just doesn't seem doable.

i know it sounds like a cliche, but there is a reason cars with COP have individual injector drivers in the pcm.
consider if you do wire them in series as most have done, if one COP goes bad, you will lose 2 cylinders.
It seems odd that no one with COP has shown a power decrease from a coilpack setup. I wonder if the people doing the testing may have had a vested interest in showing no power loss. :nonono: Looks like I've found the basis for another dyno comparison someday. Who wants to send me a COP harness for testing purposes? :cool:

from what i have seen, COP units go bad more often than coil packs.
I can second this to the tenth degree, even in platforms designed for COP.
 
good stuff striker, you beat me to it. i tried to track down some info on the COP units when i was looking into with no luck. one other thing to keep in mind is the resistance we are talking about is not as simple as measuring the static resistance of a COP unit with a multimeter. it is more complicated.
the resistance of just the primary side of the coil pack is that simple, but the rest of the circuit is not, and as such its virtually impossible to measure and calculate how much current the PCM sees. I have looked all over but every place that talks about diagnosing the COP units says you need a special diagnostic scanner to test them, and as such doesnt give any data about the units.

i know it sounds like a cliche, but there is a reason cars with COP have individual injector drivers in the pcm.
consider if you do wire them in series as most have done, if one COP goes bad, you will lose 2 cylinders. from what i have seen, COP units go bad more often than coil packs.
unless its a 90s GM coil :crazy::crazy:
 
I know not all COP are the same but some do have a procedure in testing the resitance of the cop to see if its bad. Like the toyotas from like 96 or so to 99 they have a resistance value to check if its bad then the 2000 to 2003 doesnt. It says check with a known good one. Then later than that has a resistance valvue again.
 
I know not all COP are the same but some do have a procedure in testing the resitance of the cop to see if its bad. Like the toyotas from like 96 or so to 99 they have a resistance value to check if its bad then the 2000 to 2003 doesnt. It says check with a known good one. Then later than that has a resistance valvue again.
which is fine and dandy, except for this discussion we dont care about Toyota COP units, just the ones Ford used for the Taurus and Escape.
 
I have looked all over but every place that talks about diagnosing the COP units says you need a special diagnostic scanner to test them, and as such doesnt give any data about the units.
OK, I found some info for Accel COP units for other Fords and they all seem to have a primary side resistance of about .5 to .6 ohms, which falls into the same range as the stock coil pack and most every other coil pack primary resistance that I have seen.
 
Well I thought you might have been talking in general. Anyway just food for thought, maybe the taurus oil pan is different cause it doesnt come with a mtx75 as does the escape.Last time i looked at my svt and 04 3L oil pan side by side they was pretty much symmetrical. Yeah they look a little different on the out side and the sump tray is different but there damn sure isnt a tilt in either of the 2
 
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