Using JZ's igniter in 7M-GTE (+)

[bigaaron]

What would be the difference? Once the coil is triggered, you get spark. Why would it matter if the 7m ignitor triggered the coilpack or the 1j coils? I can see that changing the ignitor might affect the timing but why would using cop change the timing? I am not saying im not wrong, but I am trying to figure this out. If this does not work out I am going to go with the msd type coils. I have $20 into this 1j cop project, no big deal to take them off if needed.

 

[Dirgle]

Ok some of you need a little clarification on how the 7M ignition system works. I read an article once that was extremely informative. It took a little while to find it again but I finally did, it was in a weird place but it's the right article. The 7M system is towards the end but the whole article is good to know. I'm not going to get in to this argument but I will give you a little info and let you work it out for yourselves.

http://www.offroadpakistan.com/downloads/tech/23 EFI#4 Ignition System.pdf

 

[bigaaron]

Dirgle, you are the f-ing man! That is exactly what I was looking for!

IGT tells the ignitor when to fire a coil.
IGA and IGB together determine which coil to fire
IGF tells the ecu when a coil has fired

Very nice. I have an idea of what I am going to do now. I will post the outcome when it is done. Thanks bro!

 

[chevyeater]

I don't think you've got enough dwell time for those JZ coils. MK4 guys have plenty of trouble trying to run wastefire with thier COPs. The 7MGTE coils are higher output than the MK4 (since they were designed for wastefire and 1/2 the dwell time) ones and don't need the longer dwell. You could use a DLI or CDI to improve the charge rate on the JZ coils if you really have your heart set on them.

 

[bigaaron]

I kinda do want to use them, as irrational or rediculous as it may be. Would 3 ignition amplifiers fix the problem? Please explain the CDI or DLI equipment, if you don't mind. So is the problem that the output from the 7m ignitor is not on long enough per cycle to charge the coils fully?

 

[siman]

I kinda do want to use them, as irrational or rediculous as it may be. Would 3 ignition amplifiers fix the problem? Please explain the CDI or DLI equipment, if you don't mind. So is the problem that the output from the 7m ignitor is not on long enough per cycle to charge the coils fully?

I would assume your right, those coils are significantly bigger than our stock coils....

Either way I commend you greatly on this project, its something I always thought about and something that would REALLY clean up the motor bay!
Not to mention improved spark/power :icon_razz

-Jonathan

 

[chevyeater]

I kinda do want to use them, as irrational or rediculous as it may be. Would 3 ignition amplifiers fix the problem? Please explain the CDI or DLI equipment, if you don't mind. So is the problem that the output from the 7m ignitor is not on long enough per cycle to charge the coils fully?

Yes, that is exactly what I'm thinking your problem is.

CDI is AEMs brand name of ignition amplifier and DLI is the HKS version. The AEM one has apparently been recalled now so that option is off the table for a little while. Basically, they use capacitors to increase the charge rate of the coils, providing a higher output in less dwell time. The HKS DLI also incorporates a transistor control circuit that is supposed to increase dwell time. You'd only need one DLI for all 6 coils, luckily. Get ready for some sticker shock when you see what it'll cost to make those $20 coils work good.

 

[siman]

Yes, that is exactly what I'm thinking your problem is.

CDI is AEMs brand name of ignition amplifier and DLI is the HKS version. The AEM one has apparently been recalled now so that option is off the table for a little while. Basically, they use capacitors to increase the charge rate of the coils, providing a higher output in less dwell time. The HKS DLI also incorporates a transistor control circuit that is supposed to increase dwell time. You'd only need one DLI for all 6 coils, luckily. Get ready for some sticker shock when you see what it'll cost to make those $20 coils work good.

Yes, the HKS one is about $550-600 bucks last time I checked:
http://shop.store.yahoo.com/sgpracing-store/hksdliignition.html

-Jonathan

 

[group a supra]

so will it work 6 coils of my motec m48 ecu which has 2 ign outputs

 

[chevyeater]

so will it work 6 coils of my motec m48 ecu which has 2 ign outputs

Only if you want to fire three of them at once (no). I believe you'll have to pony back up to the Motec bar for an "ignition expander" unless you want to use a distributor. :aigo:

 

[bigaaron]

Ok, I did some more research and I talked to a tech at MSD today too. The dwell time is not long enough AND the output current is not high enough from the stock 7m ignitor for it to fire the paralleled 1j coils. The MSD DIS-4 HO can interface with the stock ignitor, they have an inexpensive tach adaptor needed for toyotas, and (unlike the overpriced hks unit) it gives you multiple spark discrarge under 3k rpm, an adjustable 2 stage digital rev limiter and adjustable timing retard for big boost or nitrous. All that for the bargain price of around $425 retail. :aigo: The HKS unit costs more because it has HKS printed on it. :biglaugh:
It's not cheap but I just might do it. I have not ruled out the use of stock components from another vehicle though. Now I have a good understanding of how everything works so I will be looking for an inexpensive alternative and we will see how it goes.

DLI stands for "distributorless ignition"
CDI stands for "capacitive discharge ignition"
HKS stands for "Hong Kong Shanghai" or "Honk Kong Sport" :biglaugh:

The 7m-gte is a DLI system stock, I need to add a CDI box like the msd unit in order to boost the output to run the 1j coils.

 

[I<3Supras]

So i'm guessing either will work but the twin power just cost more and the msd has more abilities is that correct?

 

[siman]

So i'm guessing either will work but the twin power just cost more and the msd has more abilities is that correct?

The twin power has less fuctions as well, you cannot set rev limit ( and how fast the rev limit will hit) and you cannot program it....it is what it is.

I have always "known" about the MSD system but didnt know if thats what you or I needed to get the coils to fire right.

Looks like we have a winner.

Where can I get 1jz coils? Arent they the SAME as the 2jz coils?

-Jonathan

 

[I<3Supras]

The twin power has less fuctions as well, you cannot set rev limit ( and how fast the rev limit will hit) and you cannot program it....it is what it is.

Yeah i see but can't you do that with the aem-ems? which i plan to do in the future so i wouldn't need the extra functions that the msd system provides. So i'm guessing the Hks twin power will do fine.

 

[chevyeater]

I didn't mention MSD simply because I haven't been too impressed with thier products. They aren't as powerful as other CD ignitions, at least in practice and the MSD products I've owned and seen in service aren't reliable (notice NASCAR teams have a spare MSD on thier cars and they only need 500 miles out of them) . If you like all the bells and whistles that come with the MSD, try it out, it may be sufficient. IIRC, you'll need three of those "tach adapters" for the 7MGTE application. They two step limiter may make for better dragstip launches if you are into that sort of thing.

Autronic also makes a very high quality and high power CDI ignition (only rivaled by the currenty unavailable AEM for power output). The HKS DLI is 100% reliable, sufficient in power output and doesn't need any tach adapters, hence my recomendation.

 

[chevyeater]

Yeah i see but can't you do that with the aem-ems? which i plan to do in the future so i wouldn't need the extra functions that the msd system provides. So i'm guessing the Hks twin power will do fine.

Yes, most full featured standalone EMS's (AEM included) will do much more than the MSD box.

 

[I<3Supras]

Thats great Thanks Chevyeater that what i wanted to know

 

[siman]

so disregaurding price, the Standalone units or the simple HKS unit seems to be the best eh?

-Jonathan

 

[I<3Supras]

From what i read all u need is the Hks twin power to run the 1jz coils. So i guess yeah

 

[siman]

and.....

"you'll need three of those "tach adapters" for the 7MGTE application. They two step limiter may make for better dragstip launches if you are into that sort of thing."