Tibbi

I was contemplating this a while back, but it's way more hassle than its worth.

koreancorvette01

running on megasquirt and you have caught my curiosity.....

wheel_of_steel

Very interesting modification, and nice coil plate JonGTR. I am not familiar with ignition system modification: what are the mechanics that you are balancing to make this work correctly? Is simply matching the amount of firing time that the ECU asks of the coil, to what the coil is designed to supply? I am sure there are more complexities as well, please do tell.



I suppose this is a good place to ask: other than water exclusion, is there any reason that you MUST use the long (and expensive) style of DOHC plug lead ends,



instead of regular SOHC style plug leads?





If a guy could figure out a different way of sealing off the spark plug tubes, it may work out a lot cheaper when it comes time to replace plug leads.

XTC29

I am not using leads per say. Only the coil to plug boot and a spring that comes stock with the Chrysler coils. One reason is to eliminate the plug wires which are the most common failure point in ignition systems. The plug wires also increase resistance in an ignition system increasing power loss to plugs. Removing them you decrease resitance therefore increasing sustainable performance due to a lack of heat build in the coil and wires. Then there is the longevity factor. If a given coil fires twice as much as another its life span is reduced by half. By putting a coil on each cylinder you reduce the amount of time between failures (that is if the coils are similar in life span and not in waste spark configuration, for this they would need to be in sequential Ignition configuration.) There is also the fact of better spark output due to dramatic heat loss from less discharge/dwell time And fewer sparks per revolution. Again this is in sequential ignition configuration, or in this case a lower dwell/discharge time.



Dwell, or ‘dwell time’ in ignition systems refers to the period of time that the coil is turned on, ie that current is flowing through the primary winding and the magnetic field is building up in the coil. In the now obsolete points systems (Kettering systems) it is the time the points are closed, in our modern systems it is when the transistor (or other electronic switching device such as a MOSFET or IGBT) is on.



The voltage/current generated by the collapsing magnetic field charges the capacitor. This is the voltage/current source that is induced into the stepped up secondary winding. A coil opposes current flow while a capacitor enhances current flow. The enhancement of the capacitor balances out or cancels the opposition of the coil. The result is a faster collapse of the magnetic field and the highest possible voltage generated in the primary circuit. The capacitor has two functions: 1) it absorbs the back EMF from the magnetic field in the coil to control excessive buildup of energy that would burn out the coils and possibly the transistors in our ECU; and 2) it forms a resonant circuit with the ignition coil transferring further energy to the secondary side until the energy is exhausted.



In this case the extra capacitor/Capacitors absorb the extra energy that the coil cannot hold/discharge. Which in turn is why these coils are not going to burn out.



There are many reasons to swap to a coil on plug configuration. Just know its worth the effort.!!



I also have to change the specs I mentioned earlier. The stock coil pack has a dwell time of 1.8 ms Hyundai of Longview was incorrect. The data sheet from bwd shows the 1.6 ms dwell. Which means that ... IF..... Hyundai of Longview is correct, the adaptive dwell timing of the stock ecu will correctly adjust the dwell timing to the correct specs and increase throttle response by having a lower charge time thus giving a faster spark on demand.



I still have not confirmed the supposed adaptive dwell timing of the stock ECU.



Edited for accuracy of dwell time stats and added Info on dwell time.

tibbytib

XTC29, I'd be interested in a reproduced plate. How are you going to do this? I would imagine the machining needs to be pretty accurate.



If you don't buy it from JonGTR.....



I'd be interested in purchasing it from you Jon. So....If it's for sale.....2nd dibs?!



Sorry to high jack this thread into a sale thread. LOL!

JonGTR

I asked for interest in this back in 2007 and no one really had the need or money to convert. There may be many reasons to do it, but I don't know of anyone around here truly needing it other than turbo owners. Again, the reason I didn't go through with it before was because it wasn't worth the hassle with the power I was putting down at the time, and I didn't have a proper standalone to adjust the dwell settings. Now that I do, I plugged in the Toyota coils, adjusted dwell to 2.1ms and it fired right up. The discussion is in my turbo build up thread. These could plug n play with only a few mils of play, but expect to be burning out coils every few thousand miles. No biggy since the coils are $15 a piece.







Hijack:

I paid a CNC shop $125 to get the initial prototype cop plate made with the intent to get a batch of 25 made at $75 a piece. Then bought the Chrysler coils for $40. For $100 shipped, I'll send the plate with 4 matching Chrysler coils and their wire leads ready to wire up. All you need is some good looking hex bolts to dress it up. I have a wiring diagram around here somewhere. Sound good to anyone? XTC, then Tibbytib, then.......





Not to add an advertisement here, but you certainly can't just rest the coils on the head cover. They need to be bolted down somehow otherwise they'll jump.

XTC29

I have a CNC machine and can produce many of these plates if need be. JonGTR if Tibbytib wants the plate and coils he can have 1st dibs. I appreciate the offer. As for burning the coils up, I really don't believe its going to happen. Like I said I have been running them for many more than 10,0000 miles. Yes a mount plate is needed to make sure the coils don't "jump" as you put it, although this has never happened to me. The coil boots are very tight when installed and take a good bit of force to remove, especially after being on for a few hundred miles. The best thing about the mount plate is the custom look. It sure is a lot prettier than my setup. As for only FI guys making benefit from this setup is purely untrue. I have no other mods on this engine right now other than the 1.8l cam and inter cooler from a Mercedes-Benz C230 kompressor and it definitely upped the performance.



A bit off topic, the next mod is a Eaton M52 supercharger from the C230. I am working on a mount bracket for installation where the A/C compressor goes. no modification to the existing Intake manifold is required, neither is using an aftermarket intake/supercharger from Alpine.



Eaton M52.JPG

Tibbi

Interest piqued and pardon my ignorance, but what benefits would befit a turbo application specifically? I am interested but it depends on certain factors.

XTC29

The coil is probably the most important thing to upgrade when it comes to forced induction performance, because of the additional voltage needed to jump a spark in a high pressure, high temperature combustion chamber. They deliver very accurate spark timing. Hotter Spark, More Accuracy, Eliminate Misfires. The added coils increase the amount of energy discharged to the plugs. A sufficient amount of voltage must be supplied by the ignition system to jump the spark across the spark plug's air gap (between the ground wire and electrode nose). The temperature of the spark plug's firing end must be kept low enough to prevent pre-ignition but high enough to prevent fouling. This is called "Thermal Performance" and is determined by the heat range of the plug. So a good set of plugs are also a must.

Tibbi

Has anyone looked into the Alpha coil packs?

They may be a closer match, but I haven't the faintest. Just seems like a logical place to start