morganson's COP S-Type setup

supraguy@aol

Well-Known Member
Dec 30, 2005
4,235
37
48
Atlanta
It's 21 7/8".
Grim- it sounds as though you're saying that the DG coils are being limited on output due to the ignitor?
I'm really not that good at electricity in general. Once you're finished with the measurements, it would be awesome if you'd break down all the info on the three different coils, and give a side by side comparison, along with a short description of the parameters, as well as desireable vs. undesireable characteristics, for us noobs. That way, we can see a clear cut synopisis on what the best option is. Also, i understand that you are exploring the possibility of doing away with the ignitor altogether. It would be great if you could expand your explanation of what the possible alternative might be.
And thanks.
 

nathaninwa

New Member
Jul 1, 2012
377
0
0
Aberdeen, WA
I just figured a 2x2 sheet of material, and getting 7 coil holders from that sheet. With material and plasma time, and since I do this in the garage in my spare time Im seeing cost out the door at like 19.00 each from 1/8 material. Since its a hobby!, I can do singles or batches. Not sure what the best shipping method would be, priority mail in a tube as suggested, or something flat.

If youd like I can post some work, or even cut one out and send to someone for testing.
 

grimreaper

New Member
Jul 2, 2008
2,180
0
0
Dallas
^ No Problem. Im going to start another thread in the next few days that will cover all of this and what I have found about the ignitor and all its signals. Clever little device!

in the mean time, the ignitor current limits to 7.2-7.6 amps (limit of mV range (X) of waveform i saved) Call it 7.5 amps. The ford coils do not reach this current at any rpm over 1,000rpm or so. They should always be close to this charge level but will rarely hit it. So there output might be limited. I do not have any way to analyze the secondary side so actual output of the coil in KV/mJ is still unknown.

I've seen a few graphs of the dg508 coils needing only 5 amps or so for a full charge. Its very likely the slight undercharge is still producing an effective spark output. Especially when compared to stock 25 year old coils. Have yet to see any OEM application that push the coils to their max. The lower charge should help them run cooler too.
These could be run in parallel to reduce the charge time. Nothing I can really think of to increase the current limit though.

make sure you guys thank supraguy@aol, these are his coils i have been testing on..
 

pete05

New Member
Nov 24, 2012
64
0
0
australia
grimreaper;1981962 said:
I need to organize the scope images a bit before posting them. Way to many measurements that can be shown off one image. Makes it a cluster to see things.

The short story is this. Im almost certain the ignitor performs current sensing. A block of dwell time is provided that should allow the coil to fully charge, then current limiting takes place until the ignition event is triggered. The times listed below are from coil shorting (begin to charge) until current limiting takes place.

Stock 2.96-3.16ms
IS300: 3.16-3.2ms
Ford: 4ms+ (2 coils wired in series)

The ford coils do not reach the current limiting state at any rpm except idle. The ignitor appears to calculate a dwell window based off rpm, all calculated internally. This window has always been 3ms+ even as rpms increase. What you see on the scope is that the dwell window may 'shrink' a bit, but the coil has enough time to charge to current limiting state. Usually this window is 3.5ms-4ms as rpms increase.

At 6500rpm, the ignitor has 9.231ms per 360degrees of crank rotation. Coil for 1/6 fires every 9.231ms. Plenty of time and duty cycle left over to allow things to cool on the coil side. The stock coils need about 1-2ms to recover after a firing event, judged by the burn duration and oscillations. This varies a bit though.

The stock coils appear to be CDI coils with out a capacitor. Very low resistance. The Is300 coils are 0.6-0.5 ohms, stock 0.4-0.3ohms, ford 1.0-0.9ohms.

Installing a sense resistor to test the current ramp of each coil tonight. I believe the ford coils may be reaching a sufficient charge, although not the current the ignitor expects to see. Even if these are wired in parallel, the current limiting of the ignitor will prevent additional charge.

Once the ignitiors current limiting value is known, it should be easier to plan what will work best going forward.

Thanks for the great feed back, I look forward to any further information you provide, I am currently running this setup with 12psi boost pressure on my car with the standard ct26, the car regularly sees 6000rpm. I have just recently pull out my stock Ngk plugs and inspected them using the Ngk chart as a comparsion, the plugs appear to be burning perfectly with no signs of miss fire or and sign of the plug being overheated. The car runs clean and pulls hard all the way to red line, I have just fitted a new set of bosch platinum plugs so I will watch these and see how they perform. Also you mention running them in parallel rather than series, when talking with morganson in the early stages he said he tried parallel at the start and the car would not run.
 

grimreaper

New Member
Jul 2, 2008
2,180
0
0
Dallas
hmmm thats odd. The total current will not exceed 7.5 amps. Technically, if the coils are matched or closely resemble each other electrically, each one will consume 1/2 the 7.5 amps. exactly how the injectors are wired on the stock 7m.

might be the difference between the coils that caused one to draw more current.

If there wasnt current limiting, it would fry the ignitor by doubling the current draw. In our setup it just cuts down the charge time, or should. might be something in the ignitor that monitors for a short circuit too. Id guess the charge time being cut in half to be around 2-2.1ms Looks like i might need to sacrifice an ignitor to test..
 

morganson

New Member
Jan 19, 2012
274
0
0
Columbia, SC
I will step in on this one. If you wire them in parallel there is a feedback loop through all the coils on the 12v. The kv signal will fire all the coils at ons and you will not be able to start. The current wiring solution was the only setup that worked short of using diodes to gate the harness. In short if you string in parallel you have continuity on all pins to all coils at any time.
 

grimreaper

New Member
Jul 2, 2008
2,180
0
0
Dallas
Why wouldnt this occur with them wired in series, 12v is still shared across all the coils and the injectors on this leg of the power circuit.
 

morganson

New Member
Jan 19, 2012
274
0
0
Columbia, SC
I can't answer that question. I built a harness in parallel it didn't work, built a harness based on the dsm harness and it worked. I don't have the tools to tell you why it worked where the other didn't. The answer lies in the coils but I can't get the published information to find the answer.
 

grimreaper

New Member
Jul 2, 2008
2,180
0
0
Dallas
I did, lol. Cant sleep when something goes unanswered!

Ran the ford coils with polarity hooked up both ways in parallel and in series. Only way it works is if the 12v+ is on the right pin and they are in series. Swapping polarities drastically reduced the charge time but missfired when free reved.

parallel works but very very poorly. Dwell significantly reduced, less than 1ms.

Which pins are you guys putting 12v/gnd to?
 

satx88supra

New Member
Aug 16, 2009
388
0
0
San Antonio
So if i remember my math (Ohms Law) the ignitor is built with three series circuits. Each circuit running two coils. The return of the first series sets of the second series then the third. Parallel would cause too much voltage/amperage drop from the first fire to the last. Sounds like the ignitor is a pretty stout piece of hardware.

Sent from my LG Optimus G
 

grimreaper

New Member
Jul 2, 2008
2,180
0
0
Dallas
Close but the transistors that turn the coils on are in parallel. So it's only dealing with 7 ish amps at one time. There are three transistors in parallel.

Still one stout device. Under hood temps aren't even remotely friendly of electronics. The whole case is a heat sink
 

satx88supra

New Member
Aug 16, 2009
388
0
0
San Antonio
Wow. Learn somethin everyday. Just amazes me sometimes when dealing with this car about the tech used from back then. Well i guess if you have the know how almost anything from the new era can be Franensteined into old tech. Keep us informed. I'm really wanting to do this when i start on my car again.

Sent from my LG Optimus G