How to run LS1 Coils

Advanced discussion of improving KA-T components
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EviltoM
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Post by EviltoM »

I didnt use the coil wizard because I am the wizard :P

I just read on the coils so much that I was able to determine what would work, and the sr settings were right on. I am also using the AEm trigger disk.

The effects, aside from it not operating like its supposed to, would be overheating a coil and eventually burning it out.
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Gonad
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Post by Gonad »

Ok, I used your settings and so far so good. Motor is running normally.

Oh for those that don't know, I have an SR not a KA-T :P

Anywho the only thing I noticed was that the RPMs on my gauge (stock cluster) is off by a couple hundred RPMs as opposed to the RPM shown on the EMS parameters.

Did I miss something?
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Post by Gonad »

Ok, as I've mentioned earlier, I have an SR and past few days I have been running the LS1 coils.

So far car is driving and I've done a few WOT pulls (all the way to redline) at around 8psi and the logs look pretty good.

But today I tried upping the boost to around 11-13psi and during a 3rd gear WOT pull, around 4000rpm or so, the motor started 'breaking'.

Looking at the log this is what I see. Is this some sorta interference? Is this even coil related?

When I got home I checked the coils/plugs and somehow (hopefully) I'ms tarting to wonder if the wiring got loose or something.

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Post by Gonad »

On the way home today I upped the Dwell Factor to about 20 and noticed it didn't break as much.

According to the HybridZ site and using the formula on AEMFOrums for calculating Dwell time (or just looking at the Dwell Time parameter in AEM), I should be safe to use a 3ms dwell time range.

I'm going to use the GM LS1 Coil Dwell wizard tonight and see how things go.
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Post by Gonad »

So yea, I used the coil wizard to select the GM LS1 Coilpacks. It put my dwell to around 3.3ms (as opposed to about 1.6ms that was before) and I am getting no breakup under load now.

As well, before, I had a slight breakup on low rpm/low load and that is gone too.

I have spare coils so I'll see how these fare with these settings for now. :D

So far so good. :)
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EviltoM
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Post by EviltoM »

Right on!
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tastyratz
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Post by tastyratz »

EviltoM:
You said you are using the AEM trigger disk. I know the AEM is 24 teeth, what's stock?
If someone is not running the aem cas disk and still using stock would the ign. tooth settings need to be different?
Is that what you defined when you set spark teeth at 24 (vs basemap default 6 tooth setting)

I just landed ls1 coils with bracket and wiring harness for 60 bux shipped on ebay and will be installing these on my sohc once they come in. I will be looking at how they are wired up since its only 1 plug on the harness. Ill be sure to post it up.

I also have a link on ls1 coils with megasquirt if anyone is curious. This spells out actual testing data on dwell time vs output.
http://forums.hybridz.org/showthread.php?t=120533

Here is a link to a post by sb on the Aem forums showing how to calculate your dwell time:
http://forum.aempower.com/forum/index.p ... 519.0.html

I spoke with AEM on the phone earlier today and they told me to use the ls1 coil dwell wizard - and if I tried to monkey with it any higher I could fry the drivers on the ems itself...

Also worth mentioning... Does this cause any issues with the tach? Specifically lance could you tell me if the ls2 coils gave you tach issues on the soch? I know when I switched to the msd 6a before I needed a tach adaptor - but I don't know if I will need it now.
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Post by 240-kid »

Any tried MSD Coils?
*Yes I know it's an SR, but you get the Idear...

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Post by tastyratz »

I found another link worth mentioning. This one goes into a technical explanation of the coils functionality and its actually quite an interesting read.

http://www.megamanual.com/seq/coils.htm

Its for the megasquirt but we can adapt for the AEM.
I plan on running an interpretation of the battery voltage compensation since the default ls1 wizard doesn't compensate for it (and it obviously SHOULD be compensated for)

Reading this makes me really wish I picked up ls2 coils though :-(
LS2 coils are incredible. Even compared to the LS1 coil, these are just crushers! On the LS1 coil there is around 40 milliamps of peak secondary current with 5 milliseconds of dwell time. On the LS2/truck coil (AC Delco D585), there is 120 milliamps!
According to that diagram, the coils are exactly the opposite of ls1 in wiring order, but the same requirements (12v, signal, ecu gnd, gnd)
300% spark energy in comparison too!

The bottom of the page also has a spark plug gap calculator which is pretty interesting as well.
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Post by Truck »

http://www.msdignition.com/product.aspx?id=5093

This looks very similar to the stock coil on a s13. Perhaps it could be used instead of ls1 coil near plugs. It is MSD (multiple spark discharge) with greatly increased voltage. And you only have to buy one coil pack, plus maybe new wires for ecu ground etc. No msd ignition needed, oem replacement.

I want it. :D
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Post by tastyratz »

eh, msd is overrated
Their coils just don't hold up to snuff if you ask me.
I think you might be confused too. That's a single coil replacement but the ls2 uses 8 coils - in application you would need to buy 8 of these for the ls2. You would need to buy 4 for the KA (can't just use 1).

That coil spec's out at 150ma peak current. The ls1 generates 40ma in 5ms, and the ls2 generates 120ma in 5ms... but they can both be charged up to 8 ms. msd does not mention how long it takes to get that charge. Chances are the "advanced circuitry" in that coil just gives it an extra ms of charge time (which you can just set in the aem on stockers) I would be willing to bet you would get 150ma out of a hard charged ls2 coil... it just shortens the life.

The seller for msd products is the multispark - but with an ignition this strong it wont matter nearly as much vs our factory. also, it usually only multisparks under 3k.

I doubt its a better coil and its certainly not worth the $400 cost vs getting a set of gm ones for 60 bux on ebay.


I installed my ls1 coils last night. I haven't fired the car up yet (forgot to bring my key to the garage I work on it in... doh!)
These are on my sohc. I removed all the emissions in the back of the head and that's where I put them with the stock GM bracket and wiring harness. I was able to get stock sohc plug wires to work fine although a couple of them are a pretty tight stretch. That's fine because it pulls them tighter and away from the turbo so they don't melt.

The ends on ls1 coil wires are very small center pins vs the factory KA where your outer edge is the contact surface. I used needle nose pliers and bent the metal in the ends to make sure it made a snug fit and contact. T
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Post by Truck »

It doesn't seem like there is any reason why it shouldn't work by itself. But if you were to use the coil pack on all four plugs it could get overheated, especially since it fires multiple times.

The reason is i'm thinking you could just wire in the msd coil where you had the old coil. If the old coil, (from 89) can handle 4 spark plugs, then I would think the msd coil could do the same.

I don't really understand the reason for using all these coils anyway. :dunno:

EDIT: I went ahead and looked at the instructions for installation of this coil, and it has one picture. It is a coil near plug setup, and would require 8 coils for the ls2.
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Post by tastyratz »

Truck:
Bingo - they sell them 1 by 1 but you need 1 per cyl. so ls2 needs 8 and we need 4.
Switching to individual coils splits the load, and gives you a bigger stronger spark. This allows you to run more gap, and it will more completely combust mixtures far from stoic . More power/gas mileage/ etc. Also complete digital control for accuracy vs relying on mechanical timing.

-

I completed the ls1 coil conversion the other day on my car and got it working. Note my ignition sync value changed from 4.x to 16.x - I had to monkey with it to get the car to even start. Once I did that and sync-ed it with a light it worked.

The car really does like to run after you pull the key like people mentioned though.
The car will shudder and stumble 3-600rpm until it finally dies. The car might run another 5-10 seconds. It feels like when you just pull the fuse on the fuel pump.

I would prefer to have the car just shut off right away when I pull the key instead of dying a slow violent death every time
(especially if I have to shut the engine off because something is wrong)

Has anyone found any kind of workaround to this at all?
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Post by EviltoM »

tastyratz wrote:Truck:
Bingo - they sell them 1 by 1 but you need 1 per cyl. so ls2 needs 8 and we need 4.
Switching to individual coils splits the load, and gives you a bigger stronger spark. This allows you to run more gap, and it will more completely combust mixtures far from stoic . More power/gas mileage/ etc. Also complete digital control for accuracy vs relying on mechanical timing.

-

I completed the ls1 coil conversion the other day on my car and got it working. Note my ignition sync value changed from 4.x to 16.x - I had to monkey with it to get the car to even start. Once I did that and sync-ed it with a light it worked.

The car really does like to run after you pull the key like people mentioned though.
The car will shudder and stumble 3-600rpm until it finally dies. The car might run another 5-10 seconds. It feels like when you just pull the fuse on the fuel pump.

I would prefer to have the car just shut off right away when I pull the key instead of dying a slow violent death every time
(especially if I have to shut the engine off because something is wrong)

Has anyone found any kind of workaround to this at all?
Sorry I missed all your above posts. I had this problem too until I switched from the stock KA CAS disk to the AEM disk. The car would shut off right away.
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Post by tastyratz »

It's all good, I forgot to update. I DID end up switching to the aem cas and that fixed my problems. It also lended some sanity to my tunes which up until then were making 0 sense! cas issues extend to the sohc as well apparently. too bad - 360 deg. wheel has a lot nicer resolution than a dinky 24 tooth. What a hell of a spark I have now though. I still haven't figured out what I'm going to stick on the distributor where the old rotor was. I want to do something fun like an antenna topper. It looks so naked the way it is.
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Post by that1guy »

So in doing this do you also remove your stock ignitor?
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Post by EviltoM »

Where are you getting an ignitor from? The KA only uses a single coil with the distributor...
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Post by AK-Z »

What are the benefits of going coil pack?

If you are still running the distributor as a CAS then there is still some resistance on the engine.
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Post by AK-Z »

kedbmx wrote:
AK-Z wrote:What are the benefits of going coil pack?

If you are still running the distributor as a CAS then there is still some resistance on the engine.
ls1 coils are simply for more spark. not running a distributor just the CAS. without the CAS the car wont run. and what do you mean "resistance on the engine"?
I mean for less money you can go with a EDIS setup. I know its a minimal amount of resistance. I though it was the point of going coil pack. Wouldn't you get the same results if you just got a MSD coil?
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Post by tastyratz »

Spinning the distributor is almost no load on the engine - its free spinning with no resistance so its a moot point even if could be pulled. 1/1000 of 1hp type of deal and plays no factor.

The point of going to individual coils is a significantly
(multiples) greater spark energy with infinitely flexible timing and far more precise control over a mechanical system. You cant really tune spark dwell time on a mechanical system.

Going to an multi spark - while a good step up from stock - is a completely different class of ignition.
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Post by AK-Z »

Ok. Is there a way to run coil packs with a sotck ecu or nistune setup?
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Post by that1guy »

EviltoM wrote:Where are you getting an ignitor from? The KA only uses a single coil with the distributor...
Sorry I meant the power transistor that is located next to the stock coil. :oops:
Also, do have to run the other ground to the ecu or can you just tie it in to the other one.
Thanks in advance.
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Post by that1guy »

EviltoM wrote:Where are you getting an ignitor from? The KA only uses a single coil with the distributor...
Sorry I meant the power transistor that is located next to the stock coil. :oops:
Also, do have to run the other ground to the ecu or can you just tie it in to the other one.
Thanks in advance.
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Post by FastKA24DE-T »

How would this work on internal coil.
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Post by that1guy »

Did any of you guys have any problems with cold starts after you installed the ls1 coils? Because I didn't have any before but now I do. It seems like its not in sync when its cold out.
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Post by Impetus »

is this set up compatible with the internal coil KA's
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Post by Impetus »

So to answer my own question, yes they do work in a internal coil KA24DE. I started the install on Fri. and finished tonite. great info guys. Although some of my settings were different to get it started and running properly everything was spot on. My tuner said that it was attributed to every car just being different. thanks again guys will post pics.
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