So i'm ditching the fuel-only Haltech F9 computer, specifically due to limitations of aux outputs, but also because I know I will want a fully managed ignition down the road. Looking into the Megasquirt MSIII w/ msx board.

So I'm in the market for an ignition setup, and I'm going to need to buy everything as I currently have the GSL-SE distributor ignition, coils, and ignitors.

I'm budgeting about $100 for a complete OEM FC ignition, including CAS, and I do believe that 4 LS1 coils would go for $280 (minus CAS which would probably be like $30)

So basically the LS1 route would be 3 times the expense, but I'm wondering if I would regret not getting it right up front, and having to pay for additional dyno time and re-tune down the road if/when I decide to upgrade.

Engine setup is an S5 street port 6 port w/ VDI, 2.75" exhaust.

My goals for the car are as wide a power band as possible, ultimate streetable machine, fully track capable. Looking to get into hillclimbs and auto-x.

 

https://www.rx7club.com/naturally-as...hread-1035364/

best bang for the buck is 4 FC trailing coils…

 

You're comparing used FC stuff to new aftermarket stuff.

You should be able to get a rack of LS1 or LS2 style coils from a junkyard for $40-50. They never go bad so there's little demand for them.

 

Not comparing - asking if its worth the extra (lots) of cash for (how much?) gain?

I wouldn't even know where to start looking in a junk yard for LS1 coils. Start at the first car and go down the line? Look for cars with signs of aftermarket upgrades?

 

i think i misunderstood you when you mentioned the LS1 kit. i didn't realize that you were talking about coils ONLY. no ... please look around because better prices are out there!

a couple things i think are worth mentioning ...

1. i can't confirm the price range Peejay mentioned, but i do know that some of the Rx-8 guys buy a "full set" and split them.

2. i think the Yukon/Tahoe is one of the vehicles that they came in

3. do some homework on this before you start looking for coils because i vaguely remember reading over at the Rx8 Club (hella reliable source, i know ) that there is a potential issue with dwell times for the LS1 coils. basically, the conclusion was LS2 coils were better for our applications/needs ...

whichever ones correspond to part numbers: D585, D581 and D514A

 

the FC coils offer more spark energy than the LSx coils.

 

Find any GM truck made after 2000. If your junkyards are like ours you're not going to find anything older than that anyway so this is not a problem.

Unbolt coil rack from either side of the engine. Done.

Or you do like me and check out car-part and have them deliver the parts to the shop

 

for n/a application, you cant beat the factory coils, mazda was not fooling around in their design. best spark duration and energy output of anything ive tried so far

 

Awesome - thanks for the tip on the OEM setup guys.

I'm either going 4x trailing, or just the stock dual leading coil, individual trailing coils. My buddy told me that because I'm NA I wouldn't benefit from 4x trailing coils much?? Seems to me that direct coil-near-plug x4 would be the tech. What's the practical difference? anyone got some links I could read up on?

 

I don't want to seem stupid, but how would you wire this setup?

Eric

 

+1 this would be my next question!

 

with 2 trailing ignitors.

 

with 4 coils, you need 4 ignitors. i think gxl90rx7 is running a subaru ignitor, which is a single 4 channel unit. you can also run 4 one channel ignitors, like the leading FC ignitor

 

I thought the igniters were built into the coil packs??

 

I just ordered my Mercury IGN-1A set today. If your ECU can support 4 ignition outputs you can use these. These have the ignitors built in, pretty well priced also.

Hit me up if you want a set.

 

Forgive my unknowing questions, but is it better to split the signal leads to the coil packs and run the 4 coils from the split signals? I am looking for a stupid person wiring diagram.

Also I am assuming that you use one of the trailing coil spark plug wire recepticles and block off the other one.

Yes???? I can do the mechanical or physical setup of the systems, I am a bit uncertain as to the theories of exactly how to do it.

Thanks,

Eric

 

im unfamiliar with MS ecus, but if you have 4 ignition outputs (direct fire) bosch makes a really nice ignitor module that puts out more current than the factory ignitors. use this with the factory coils, charge to 4-5ms and you would have a beastly spark

Bosch 0 227 100 211 Ignition Control with MegaSquirt-II

if you are lmiited to running factory setup (wasted leading spark and toggled trailing), you can actually run direct fire by swapping the factory leading coil with a trailing and splicing into the toggle signal. I think BDC has a writeup for it in the haltech section of this forum. you have to run the factory ignitors in this setup to get the toggle function, which max out at around 3.5ms charge.

you could also run the bosch ignitor on wasted spark too and you could squeeze a little more energy out of them, but it will not be ideal. the leading coil has less energy output than the trailing, since it gets fired into two spark plugs instead of one

 

Can anyone else confirm that you can use any LS1 coils that are made after 2000?