1jz coils on a 7m, here's the wiring diagram

[limequat]

I have heard several people say that the 1j coils do not work well with waste spark, but I think that is just info regurgitated from some unknown source,

I think there is some confusion on this. Prior to the dual ignitor idea, this was true. If you were to try to run 1J coils on a SINGLE ignitor setup, it would surely affect ignition, as the current would choose the path of least resistance.

I will be testing the secondary voltage of both setups to see if there is a big difference. The miss I was experiencing could be totally unrelated because I had a small idle issue before I installed the new ignition system. What would make you believe that the stock coilpack with dual secondaries would be able to handle any higher frequency then the 1j cols? We are only talking about 6500rpm here.
They are both made with a similar design and materials, the 1j coil is just mounted on the plug. I would think that the coil mounted on the plug would be able to handle higher rpm because there is no extra impedance added from spark plug cables. Also, what makes you think that on a stock 1jz ignition system the ignitor output is actually on for any longer on a 7m? I do need to check this, I better dust off the o-scope again... There is a certain rise time but after that the coils would just overheat and the spark would not get any hotter

If anyone can prove me wrong on any of this then please, let's hear it. This is a "open source project" now, right?

You are correct about the coils. Required dwell time is proportional to coil size. The dual ignitor setup should be good to a higher engine speed than stock.

I think the only question about this being and upgrade or downgrade is that regarding of the coils themselves. This could be calculated if we new the number of windings of each side...but I'm inclined to say that if it's good for a 1J, it's good for a 7M.

Thanks for sharing, Aaron.

 

[bigaaron]

Well I have lots of trouble free miles on this setup now. The miss I mentioned early on turned out to be a combination of a hard to find boost leak and some old crappy engine ground cables. Now I have run 25psi with no hint of any ignition issues. It's set at 18psi daily and it spends more time at 18psi then at 0psi when i'm driving :naughty: I'm going to try and put on a 60trim ct26 (to replace the 50trim) before Vegas and take care of an exhaust restriction I have had for a while. I have the stock 2.25" dp flange bolted to a 3" high flow elbow with 3" piping welded to the flange.

 

[Dirgle]

Hey bigaaron, that was really cool of you to throw that diagram up. I noticed it while searching the web the other day and just now saw this thread. I'm glad to hear you got the kinks worked out. I had a few ideas of how you did it but didn't have anyway to test it so I kept quite. It seems your way is a little different than mine, but since yours works well stick with that. One question though, was there a reason you went with a buffer instead of a voltage follower?

 

[bigaaron]

Thanks! I went with that IC because it can source up to 500ma! TTL or CMOS ic's would probably not be up to the task. Basically you are just taking the output from the ecu and making two outputs without loading down the outputs of the ecu with two ignitors in parallel. This is the only high current, non inverting buffer I could find from any manufacturer, but if you can find something better then we could try it out.

 

[bigaaron]

Oh, and I got an adjustable 12-24vdc 60w dc to dc power supply to up the voltage to the coils but at redline the coils can draw over 7 amps! That is 105watts at 15 volts! I only got a 60w unit so I didn't even try it yet.

 

[Allan_MA70]

just wondering if the 1jz coils will fit under a NA intake manifold?

 

[bigaaron]

Try it and let us know :icon_bigg

 

[Allan_MA70]

i will Soon! yoU see im waiting on my 1jZ-gtE coils turn up from some slacker

I REALLY dont want to cut and shut manifolds but i know some one with a TIG moohhahahahah *cough* Ian *cough*

i wont get to play with toyota ignitors tho i have stumbled across a ecu with sequentual ignition

 

[NavySupra]

Does the increased voltage to the coils risk having them overheat and fail?

 

[Allan_MA70]

more performace = less life, what go's up must come down... same thing

*throws apple at your head*

 

[NavySupra]

more performace = less life, what go's up must come down... same thing

*throws apple at your head*

Normally I would agree with you, though this is a 7m we're talking about here. I mean if you do one little thing wrong to the engine it sucks your wallet dry.

 

[suprra_girl]

i will Soon! yoU see im waiting on my 1jZ-gtE coils turn up from some slacker

I REALLY dont want to cut and shut manifolds but i know some one with a TIG moohhahahahah *cough* Ian *cough*

i wont get to play with toyota ignitors tho i have stumbled across a ecu with sequentual ignition

LMFAO

blame the slacker nz post

should be there tomorrow

 

[Allan_MA70]

LMFAO

blame the slacker nz post

should be there tomorrow

if there here on a sunday ill give you a supra! maybe even a hug if your lucky!

ohh and i found the pressure sensor! ill post that monday if i get a chance

 

[suprra_girl]

ahh but if you look at the time i posted technically "tomorrow" would have been monday

woohoooooooooo... now i just gotta get a 550 chip
a japanese one :icon_conf

 

[NavySupra]

edit: opps wrong thread.

 

[Allan_MA70]

ahh but if you look at the time i posted technically "tomorrow" would have been monday

woohoooooooooo... now i just gotta get a 550 chip
a japanese one :icon_conf

ok you can still have a supra... but no hug

 

[bigaaron]

Sorry to dig this up from the dead but I have something to report. I thought that the miss I was experiencing was from a voltage problem, but it was not.
Check this out:




So now I am more confident then ever in my design. 4 of 6 coils had cracks in them. When the engine is under heavy boost the resistance through the plug is much higher, and the spark takes the path of least resistance which is to the head itself through the crack in the plastic. This causes a misfire that can be sporadic and hard to diagnose.

 

[suprra_girl]

2 pac epoxy/resin
coat em up and go again

we had that problem too and spent way too much money on replacing coils

 

[bigaaron]

I already did this on a set:

1" shrink wrap

 

[Boostaddctn]

Anyone else with a 7m do this?