Chewievette Posted September 19, 2006 Share Posted September 19, 2006 I have been wanting to upgrade the ignition on my daily driver for quite a while now to coil per cyl using LS1 coils but I havn't been able to figure out what I need to know to get it to run correctly. I have a coil pack with three pairs of terminals to run my v6 in a waste spark type ignition. I want to split it up into six individual coils but I need to know what numbers to look for when shopping for coils. What needs to be the same for my stock ignition to not freak out and die. All I want to do is run six coils but keep the waste spark so that I dont have to make some sort of sequencer. I hope this is making some sense. I guess what I'm trying to say is, what do I need to know when looking for the coils? Should I look for performance coils right away or stick to off the shelf parts until I get the system working? Quote Link to comment Share on other sites More sharing options...
dapiper Posted September 20, 2006 Share Posted September 20, 2006 I use the LS1 coils in wasted spark on a brkt mounted to valve cover bolts. Brkt was plazma cut then each coil mtg has angle brake for stiffness. See my pix in member pix. I can get more made. The 3 guys at SEZ that wanted one are you reading this? Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 20, 2006 Share Posted September 20, 2006 I must be missing something - what is the advantage to doing this? Quote Link to comment Share on other sites More sharing options...
Chewievette Posted September 20, 2006 Author Share Posted September 20, 2006 I must be missing something - what is the advantage to doing this? -Its something to waste my money on -It looks cool -I'm building a custom intake manifold, twin turbo setup, modified porsche six speed, custom built engine, etc... basically I'm shooting for 450hp from my little fwd v6. A set of performance LS series coils from MSD would look and I assume perform really well under the hood. and in case your wondering, its only my daily driver till I find another car to replace it which will be very soon. I use the LS1 coils in wasted spark on a brkt mounted to valve cover bolts. Brkt was plazma cut then each coil mtg has angle brake for stiffness. did you just plug the coils in and hope for the best or are there numbers attached to your conversion? I'm just worried I'll do the conversion and it'll stop running Quote Link to comment Share on other sites More sharing options...
Phantom Posted September 20, 2006 Share Posted September 20, 2006 You might also look at the setup used on the GM 3.8L V-6. Quote Link to comment Share on other sites More sharing options...
dapiper Posted September 21, 2006 Share Posted September 21, 2006 Accurate, repeatable spark timing permits higher output on 93 octane fuel. More reliable than MSD and less parts and interconnection wiring. Obviously more dwell time, smaller package, shorter wires, less EMI. Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 21, 2006 Share Posted September 21, 2006 Accurate, repeatable spark timing permits higher output on 93 octane fuel. More reliable than MSD and less parts and interconnection wiring. Obviously more dwell time, smaller package, shorter wires, less EMI. I guess the way I read that was that he was going from 3 coils in waste spark to six coils, but also in waste spark. So, even though there is now 1 coil per cylinder, each of them still fires once every 360 deg of crank rotation, so there would be no advantage in dwell time, wiring, EMI or packaging. That's why I said I must be missing something. Quote Link to comment Share on other sites More sharing options...
Phantom Posted September 21, 2006 Share Posted September 21, 2006 Well - actually - since the engine is a 4-cycle - they fire once every 720° of rotation. 6 coils will fire half as often as 3 coils asuming thy're set up the same way which allows the coil more recovery time and the shorter coil-to-plug wire results in reduced EMI and reduced power losses through the wire. We're dealing in very small differences here but perhaps the big question is - If there isn't a significant advantage to it why would GM do it? Look at the performance of the LSX motors vs the earlier generation engines - in stock form - and it is pretty apparent. Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 21, 2006 Share Posted September 21, 2006 Well - actually - since the engine is a 4-cycle - they fire once every 720° of rotation. 6 coils will fire half as often as 3 coils asuming thy're set up the same way which allows the coil more recovery time and the shorter coil-to-plug wire results in reduced EMI and reduced power losses through the wire. We're dealing in very small differences here but perhaps the big question is - If there isn't a significant advantage to it why would GM do it? Look at the performance of the LSX motors vs the earlier generation engines - in stock form - and it is pretty apparent. No - that was my point. He said he was still setting up the 6 coils in waste spark, which means they will still be firing at the same rate as three coils (every 360 degrees), there will just be twice as many of them (coils, that is). I understand why you would want to go to coil per plug, but this setup would not reap any of the advantages. Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 22, 2006 Share Posted September 22, 2006 I understand why you would want to go to coil per plug, but this setup would not reap any of the advantages. I should clarify this - I meant to say that this would not have an advantage over the 3 coil waste spark setup. Sorry if I offended anybody - should have worded it better. Quote Link to comment Share on other sites More sharing options...
Chewievette Posted September 22, 2006 Author Share Posted September 22, 2006 Since I'm retaining waste spark, you are correct, mostly. The one advantage that coil per cyl would have is shorter wires. My coil pack is currently one huge pack with three seperate areas each with two terminals. The wiring hookup only allows to be split into a three coil waste spark(which is how it is done internally already) however with some splicing it can be easily made into a six coil waste spark. but I have been doing research on how to build a sequencer that would switch between one cyl and the next cyl every time it gets the fire signal. which would allow it to operate non waste spark even though the ecu still thinks it is. Quote Link to comment Share on other sites More sharing options...
Phantom Posted September 22, 2006 Share Posted September 22, 2006 TimZ - It didn't click with me before that the ignition would be firing two coils simultaneously each rotation like it does when using a single coil to fire two plugs, one essentially at TDC and the other at BDC, each rotation. One more advantage of the coil on plug set-up would be that you'd only lose one plug if a coil fails! I'd sure be looking at a way to eliminate the waste spark function and let those coils fire only once each 720°. Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 22, 2006 Share Posted September 22, 2006 Since I'm retaining waste spark, you are correct, mostly. The one advantage that coil per cyl would have is shorter wires. My coil pack is currently one huge pack with three seperate areas each with two terminals. The wiring hookup only allows to be split into a three coil waste spark(which is how it is done internally already) however with some splicing it can be easily made into a six coil waste spark. but I have been doing research on how to build a sequencer that would switch between one cyl and the next cyl every time it gets the fire signal. which would allow it to operate non waste spark even though the ecu still thinks it is. Okay - better packaging makes sense. I really didn't mean to make that big a deal out of it - I was just concerned that it sounded like maybe you were going to a lot of work for a performance gain that wouldn't materialize in the way you expected. Phantom pointed out that you will get better failure modes, and also, you will probably get a bit stronger spark since you don't have to pull it through two spark gaps. The dwell time advantage just won't be there unless you implement the sequencer that you spoke of. Quote Link to comment Share on other sites More sharing options...
Chewievette Posted September 22, 2006 Author Share Posted September 22, 2006 Ah yes, its all becoming clearer. As you can probably tell I'm still trying to stumble through some of this and what you guys are, and have been saying is all starting to make perfect sense. The sequencer that I'm trying to develop is acctually much trickier than I originally thought because it is easy to make a circuit switch back and forth, like a turn signal, the hard part is making it remember where it was the next time you start the car, if it doesn't then the car wont run at all. Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 22, 2006 Share Posted September 22, 2006 The sequencer that I'm trying to develop is acctually much trickier than I originally thought because it is easy to make a circuit switch back and forth, like a turn signal, the hard part is making it remember where it was the next time you start the car, if it doesn't then the car wont run at all. Yes, that's right - you'll need some sort of cam position sensor so that you can tell whether you are on compression or exhaust at #1tdc. For my L6, I went out and got a stock electronic distributor and modified it for this purpose. Basically, I eliminated the vacuum and mechanical advance mechanisms, and ground off 5 of the six trigger teeth, leaving just the one for #1. Quote Link to comment Share on other sites More sharing options...
Chewievette Posted September 22, 2006 Author Share Posted September 22, 2006 I've been looking into the possibility of using the stock crank position sensor to run my sequencer. I'm sure its possible I just need to figure out exactly how. Since my car came from the factory with electroic ignition, there is no provision for a distributor. Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 22, 2006 Share Posted September 22, 2006 I've been looking into the possibility of using the stock crank position sensor to run my sequencer. I'm sure its possible I just need to figure out exactly how. Since my car came from the factory with electroic ignition, there is no provision for a distributor. I don't think that crank position is going to be enough. If your engine (what engine was it again, all I remember seeing was that it was a v6) ever came with sequential fuell injection/ignition, you might be able to find a cam angle sensor for it. Quote Link to comment Share on other sites More sharing options...
Chewievette Posted September 23, 2006 Author Share Posted September 23, 2006 The engine is the 3.3L v6 in a Dodge Intrepid. It came stock with sequential fuel injection and DIS. It has Both crank and cam position sensors and from what I've discovered, it reads the crank position then finds which is the next cyl at tdc to know exactly where the crank is. The cam position sensor acctually has marks for all six cylinders I just have to figure out how to tell my sequencer which is which. Maybe I could use the fuel injection system to fire the coils, I'll have to look into that. Quote Link to comment Share on other sites More sharing options...
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