280zex Posted May 9, 2013 Share Posted May 9, 2013 So I have been surfing the web for standalone COP ignition systems. There are few and very expensive units available. I do not run megasquirt, nor am I going to buy one just to run my ignition. I have decided to build my own out of existing Datsun ignition components and motorcycle COP coils. Why motorcycle coils??? My system will be a waisted spark COP / hall effect triggered unit. In a cop / waisted spark configuration there is 2 coils firing at the same time. So in effect when my engine is spinning at 6k rpm, my coils will be firing at 12krpm, I.E. 2 sparks per 1rpm. Automotive COP coils cant do this, however motorcycle COP coils can!! There is new types of COP coils on the market now, they are "smart". You can identify them easy, they usualy have 3 wires, some have 4. They have built in IGBT semi-conductors. IF you take an original Datsun 280z ignition pick-up unit and wire that to a "smart" cop coil you can get one hell of a ZAP!! TRUST ME zap zap zap!! I got nailed but good What about spark advance and retard?? My modified dizzy will be "locked" so no mechanical/vac movement. I plan on using a 555pic flyback board to delay the hall trigger event. Instead of using the installed variable resistance "knob" I will be using a 3 bar map unit and converting its variable output voltage signal into a variable resistance signal. What this does is this: my dizzy is locked at my maximum total advance, 38 deg btdc. When I then start my engine the vac signal from the map goes to the 555 board. Now depending on the map signal VIA the 555 board is where I get a trigger signal delay for my coils. Lots of vacuum = no signal delay = initial locked dizzy settings set at 38 deg btdc, NO vacuum = signal delay via 555 = LESS total ignition, or elecronic retard!! So far I have been working with some people on an electronics forum. I have been designing my circuit boards and doing the math. They in turn are giving me the yes/no answers I need. That being said, I am currently learning on how to etch PCB board and trying to figure out how to package the electronics. I have to do this correctly due to EMI kick back from the coils. Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 9, 2013 Share Posted May 9, 2013 I think that your reasoning for motorcycle coils might be off. Wasted spark doubles the load, COP reduces it to 1/6 (six coils instead of one). So a reduction to 1/3 the load of a single coil system - 2 * 1/6. A three coil wasted spark would be 2 (the doubling) * 1/3 = 2/3 the load of a single coil system. So your COP wasted spark reduces the load to half of a standard wasted spark setup but still doesn't need motorcycle coils. Your math might be assuming that all coils fire at any single cylinder's combustion cycle. That would be a lot of wasted spark and each coil would see the same duty cycle as a single coil. The only benefit would be redundancy of coils to allow the engine to keep runing if a coil failed. I think that the MSD 7AL uses spark retard for timng control also (not positive, it's hard to find rechnical details on it). Controlled by dials on the box or programmable by computer. My reasoning or understanding could be off. Looks interesting though. Quote Link to comment Share on other sites More sharing options...
Domzs Posted May 9, 2013 Share Posted May 9, 2013 Interesting . Quote Link to comment Share on other sites More sharing options...
280zex Posted May 9, 2013 Author Share Posted May 9, 2013 I think that your reasoning for motorcycle coils might be off. Wasted spark doubles the load, COP reduces it to 1/6 (six coils instead of one). So a reduction to 1/3 the load of a single coil system - 2 * 1/6. A three coil wasted spark would be 2 (the doubling) * 1/3 = 2/3 the load of a single coil system. So your COP wasted spark reduces the load to half of a standard wasted spark setup but still doesn't need motorcycle coils. Your math might be assuming that all coils fire at any single cylinder's combustion cycle. That would be a lot of wasted spark and each coil would see the same duty cycle as a single coil. The only benefit would be redundancy of coils to allow the engine to keep runing if a coil failed. I think that the MSD 7AL uses spark retard for timng control also (not positive, it's hard to find rechnical details on it). Controlled by dials on the box or programmable by computer. My reasoning or understanding could be off. Looks interesting though. yes the msd 7 box is nice, the price is not. My system is a dual fire 6 coil cop. so each cylinder has a coil, but they fire on intake and exhaust. This is why I need the motorcycle coils. I dont have much saturation time. I have already tried with LS1 cop coil and it just didnt do the job. The 1100 ninja coil worked like a charm!! Quote Link to comment Share on other sites More sharing options...
zack_280 Posted May 9, 2013 Share Posted May 9, 2013 (edited) What NewZed was trying to say is that a standard coil fires 3 times per revolution in a 6 cylinder motor (more in an 8 and less in a 4), so at 6kRPM it is firing 18k times per minute. You are putting a wasted spark COP ignition system so it is firing 6k times per minute at 6k RPM on a 6 cylinder motor. 6k < 18k so an 'automotive' coil could work. Note that you only spark once per every 2 crank revolutions 'normally'. In wasted spark you fire once every revolution. Edit: fixed my math. Edited May 9, 2013 by zack_280 Quote Link to comment Share on other sites More sharing options...
280zex Posted May 10, 2013 Author Share Posted May 10, 2013 What NewZed was trying to say is that a standard coil fires 3 times per revolution in a 6 cylinder motor (more in an 8 and less in a 4), so at 6kRPM it is firing 18k times per minute. You are putting a wasted spark COP ignition system so it is firing 6k times per minute at 6k RPM on a 6 cylinder motor. 6k < 18k so an 'automotive' coil could work. Note that you only spark once per every 2 crank revolutions 'normally'. In wasted spark you fire once every revolution. Edit: fixed my math. your right! I goofed on my math, oops. I'm not sure why my LS1 coil over heated then?? Right now I'm on the hunt for the most compact cop coil. I have found some pen styles that might work. Looks like its time to go back to the junk yard and have a look around again. Quote Link to comment Share on other sites More sharing options...
280zex Posted May 10, 2013 Author Share Posted May 10, 2013 this is my basic circuit design. this is how I first wired things up, and zapped the hell outa me!! Quote Link to comment Share on other sites More sharing options...
Domzs Posted May 10, 2013 Share Posted May 10, 2013 With your plan , each coil fires 2 cylinders , then GM coils would be the cheapest way to go . Quote Link to comment Share on other sites More sharing options...
NewZed Posted May 10, 2013 Share Posted May 10, 2013 You didn't mention the RPM component of your timing control scheme. Only manifold pressure. Maybe it's in there just not described. By the way, as you can see from your diagram, the 280Z sensor won't work in that scheme. It produces its own voltage as the rotor tip passes by. It doesn't have external power. Quote Link to comment Share on other sites More sharing options...
280zex Posted May 10, 2013 Author Share Posted May 10, 2013 You didn't mention the RPM component of your timing control scheme. Only manifold pressure. Maybe it's in there just not described. By the way, as you can see from your diagram, the 280Z sensor won't work in that scheme. It produces its own voltage as the rotor tip passes by. It doesn't have external power. Probibly why the system failed. Looks like this is what I'm after, however I would need to make the rotory vane myself then... http://cherryswitches.com/product/digital-vane-switch-vn1015/ Quote Link to comment Share on other sites More sharing options...
zack_280 Posted May 10, 2013 Share Posted May 10, 2013 How are does your ignition module fire three separate outputs? You would have to have three separate firing reference points to do wasted spark. Are you using 3 Hall effect sensors? Quote Link to comment Share on other sites More sharing options...
280zex Posted May 10, 2013 Author Share Posted May 10, 2013 How are does your ignition module fire three separate outputs? You would have to have three separate firing reference points to do wasted spark. Are you using 3 Hall effect sensors? yes, separated by 120 degrees Quote Link to comment Share on other sites More sharing options...
280zex Posted May 10, 2013 Author Share Posted May 10, 2013 With your plan , each coil fires 2 cylinders , then GM coils would be the cheapest way to go . this type of coil will not work with my system. It is a "dumb" coil, I.E. it has no built in IGBT circuitry. the newer COP coils have integrated circuits that can provide internal triggering. This is how the newer ignition units can separate the "signal" from the actual trigger, thus preventing EMI back flow from the unused voltage off the coil. Quote Link to comment Share on other sites More sharing options...
kopcicle Posted July 7, 2013 Share Posted July 7, 2013 http://xs650temp.proboards.com/thread/7899/19-junkyard-electronic-ignition and http://www.gofastforless.com/ignition/tfi.htm just some cool reference material ... ~kop Quote Link to comment Share on other sites More sharing options...
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