LS2 Ignition Coil Swap DIY pics/vid/reference

[Dragon Humper]

Judging by the write-ups I have seen about these coils, there should be no reason why you can't run about .060" with a stock setup, they're that powerful. If I can run .050" at full rage that should translate into about a 10lbft jump all through the rev range.

Running a big fat gap helps everything, throttle response, spool, torque.....etc. I was running a .070" gap on my Omni with a Crane Cams Hyfire setup, made 20 more HP with only that change.



Jon.

[nimblestix]

Judging by the write-ups I have seen about these coils, there should be no reason why you can't run about .060" with a stock setup, they're that powerful. If I can run .050" at full rage that should translate into about a 10lbft jump all through the rev range.

Running a big fat gap helps everything, throttle response, spool, torque.....etc. I was running a .070" gap on my Omni with a Crane Cams Hyfire setup, made 20 more HP with only that change.



Jon.

Very good to know! I'm going to widen the gap this weekend.

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[Black BNR32]

interested in doing another harness or even a group buy?

[nimblestix]

i could look down that road, but i don't think it would be worth my time or you're money, after parts and labor the price would be close to that of new splitfires, this mod is really best done on your own to reap the rewards of a cheaper better ignition system.


If you wanted me to make you a harness we could maybe work something out, but it would only be partially completed for plug n play status because you need to cut out your ignitor and wire in the other half of the weather pack connector.

Pm me if you want to get serious about it though, im open to ideas! I could maybe think about even doing a full pre fab ls2 ignition kit for the right price.

[gezed]

does the other LS2 coils perform just as well as the truck coils?

from what I've read there's 2 types of LS2 coils, the truck ones being AC Delco D585, and the AC Delco D514-A for 06 vettes and GTO's

visually only difference I can see is that the truck coils have a aluminum heatsink

I'm guessing having the heatsink is definitely a plus, but in terms of ignition performance they should be the same?

[Dragon Humper]

The only "high output" coil is the truck coil with the heat sink. LS2 will work too but won't have the kind of amperage across the gap that the truck coils will have. Voltage is only part of the story, sure 45,000 volts is really good but you need some decent amperage in there as well to help push the spark across the gap and keep it lit for the full shot when you are running a lot of boost.

The truck coils are a higher wattage coil, hense the heat sink.




Jon.

[M13]

Great mod Brent, congrats on bringing DYI back.

[gezed]

going to attempt .9-1mm gap on 20psi boost with these coil packs on my dyno tuning session coming up, I'll post the results when it gets done

[nimblestix]

Excellent, I will post my results too once I go in for my power tune.

George, have you decided on a tuner?

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[gezed]

Yuri from Monkeynutz will be doing my tune, he actually didn't know how to set up the dwell times with the Power FC since it uses wonky units so that the ramp is rpm vs degree of rotation

After some calculations, I got the numbers needed for a 5ms dwell time, is that what your setting is at?

[Dragon Humper]

That's what he said, 5ms. That's what most of the writeups on these coils have stated that 5ms is plently of time without overworking the coils and shortening their life. A bunch of testing on the coils found that going past 5ms doesn't increase the voltage at the gap very much and the coils ran noticably warmer.

Let us other PowerFC guys in on the calcualtions to get 5ms dwell if you could, going to this setup as soon as I get a set of coils.....and time away from the wife and kids...lol.



Jon.

[gezed]

ok well the setting on the PFC tuning software Datalogit is called Dwell Time VS RPM and it looks something like this:

10000--------107°
8000---------86°
4000---------46°
2000---------25°
1000---------15°
400----------10°

these numbers are for the stock ignition system, and they represent how many degrees of rotation the computer is going to charge a particular ignition coil for so if you want to convert to time first you have to recalculate rpm into rps

Lets take 8000rpm for example, 8000/60 = 133 rotations per second

you then take 1/133 rotations/s to get .0075 seconds or 7.5ms PER rotation

now you look at the value 86 degrees given on the PFC, that means it will be charging the coil 86/360 of the rotation(rotation being 360 degrees)

now to get the dwell time in ms you simply multiply 7.5 x (86/360) = 1.79ms, this being dwell time for stock coil packs,

if you want 5ms dwell time at 8000rpm then you basically want 66% of 7.5ms which converted to degrees of rotation is: .66 x 360 = 240 and there you have it, the value you need for 5ms dwell at 8000 rpm

obviously at lower rpms, the rotational speed is lower thus you can see how the values are ramped accordingly

to save you guys the trouble of all that calculation crap heres the new values:

10000 -----------------101-----------------------------300
8000--------------------82-----------------------------240
4000--------------------43-----------------------------120
2000--------------------24------------------------------60
1000--------------------14------------------------------30
400-----------------------9-------------------------(left alone)

found it on NICO club

[Dragon Humper]

Thanks a heap man, Datalogit is a must too. Finally going to step up and get it. Holy crapola the stock dwell is short, I bet the bumped up dwell would help the stockers a bunch too.


Jon.

[Black BNR32]

hmmm, haven't heard of anybody bumping the dwell on the stockers. time for some research.

[gezed]

id be careful doing that, you can easily overheat stock units