JZ coils and standalone EMS's

[becauseican]

I have been fighting these JZ coils/ ignition on every car that we tune here. No we all know that JZ coils like to crack at the screw area where it mounts to the bracket and under the plug boot, which causes missfire at higher boost. When ever we get to the dyno, and try to run 17-20 psi we get spark blow out/ ignition breakup....so pull the plugs, gap them smaller sometimes down to .022" , and it helps a bit, but still happens. I always go over the coils, and epoxy up any cracks that may be there. We have had these ignition problems with Microtech, Haltech and AEM EMS's, with factory ignitors. We used a HKS DLI and it worked on the AEM, but I feel that it is just masking a problem.

Now the question is what is the problem?, the weak factory coils, or the ignitor?. I really dont want to have to replace the coils on every car we try to run 17+ psi on. What ignition setups do you guys use, new coils, LS coils, AEM pencil coils, or just add a HKS DLI ?. I have heard that the factory ignitors are not so good, so will an aftermarket ignitor do the trick?

Thanks,
Randy

 

[rakkasan]

I don't know the exact answer, but I'm going to switch to HKS DLI in the near future. I don't want to have an add on ignition system when I can control a completely different system with stand alone.

 

[10secdream]

The problem lies in that most standalones operate in wastefire. The solution is an hks dli, different coils or a full sequential ignition.

 

[becauseican]

Well this "spark problem" plagues me with stock ECU cars and Standalone cars, which leads me to belive that its the coils. One one car after it was breaking up at 15 psi, we put another set of coils in and we were able to get up to 17 psi before it was breaking up again, this was with a Microtech LTX12. All the EMS's we were using were running full sequential. We did try to play with the dwel and it helped a bit.

 

[2jz88mk3]

I did a bit of searching. Most people complain about the coils being 10+ years old and new ones would fix the issue. Some people replace them with LS1 coils becuase of more spark power and the ignitor is built in (cheaper) but supposedly leads to a very cluttered engine bay. The same people recommending LS1 coils (they use them with haltech) said if you have the money new oem coils + HKS DLI would deliver more powerful spark.

... everyone using msd says its hit or miss.

One bit i found said the ls1 was better then stock coils plus HKS DLI but it would seem they were comparing old coils helped by DLI vs new LS1 coils...

hope that helps...

I was wondering lately if anyone has stock ignition issues at 500+ rwhp... i suppose i have my answer

 

[Turbo Drifter]

Its a simple fix, buck up and get new OEM coils most the time the coils are 15+ years old. The Cracks are part of the problem the other one is that as they age the coils resistance goes out of spec.

AEM running stock coils needs some kind of amp (HKS DLI) as they are batch fire. In batch fire the stock coils do not have enough charge time and leads to a weak spark.

If you want to keep stock coils spend the $400 and get new coils and a then a HKS DLI do not be cheap and look for lame band aid fixes.

You guys have to rememeber things go bad coils being on of them. Look at any MKIV making good power on stock coils and they have new ones. Its one of those costs that go along with the power, same as getting bigger injectors.

I have swapped over to LS1 coils and they fit under the stock coil cover on my 2jz. The reason I went this route is I wanted to lose the ingniter and have a EMS direct to Coil wiring. I also wanted the power of the LS1 coils and I would be able to run a larger gap .030+.

I now have my car running on the ViPEC V88 and LS1 coils, I will find out soon how this works out. I know with the testing the coils I have a much much larger spark with the LS1 coils.

I maybe putting the bracket to fit the LS1 coils into production soon if any one is looking at going that route.

Jeremy

 

[rakkasan]

I maybe putting the bracket to fit the LS1 coils into production soon if any one is looking at going that route.

I'm interested, let me know what's planned.

 

[10secdream]

Interested as well. How much do LS1 coils go for these days?

 

[BLK-SUPRA]

I'm interested, let me know what's planned.

Same here.. im interested in the LS1 brackets, but are the 2JZ coil packs the same as the 1JZ? cant we just use them or do they also tend to crack?

 

[IJ.]

With the MoTeC I run some extra dwell at high boost to prevent the spark blowout at torque peak, this way I can be gentle on the coils for day to day use and it only drives them hard when needed.

ie: I run 2.3ms @ atmospheric and 5.0ms above 15psi when at 13v.
(rough interpolation between the 2)

Not sure how configurable your ECU's are for dwell and you'd need to find out how hard the Jz coils can be driven but I find this approach cured my issues.

 

[10secdream]

So with dwell in mind how far can the stock JZ coils be pushed before they overheat? I currently have my dwell set at 3.5ms under all conditions. Would it be safe to bump it up to 3.75 or 4?

 

[t4boost]

ls1 coils will not work if your using the wasted spark setup though right?

 

[becauseican]

I hear the LS2 truck coils are smaller in size, anyone confirm this?.

 

[Turbo Drifter]

I hear the LS2 truck coils are smaller in size, anyone confirm this?.

No they are not, in fact they are a bit larger than the LS1 coils as they have a heat sink built into them. They are also triggered a bit differently.

I have LS1 truck coils in my car and they are about as small as you can get size wise that fits in the 2jz.

The LS1 coils are a huge improvement over the 15 year old 1/2jz coils. You do need to have a standalone to properly utilize them though. With my ViPEC V88 I have the dwell set quite conservatively right now as I have not put any power though it yet. My Dwell is set on a few factors i.e. Voltage (at lower voltage you need more Dwell to charge the coil) and RPM. At around 11.5 volts (usally seen when cranking) I have 7ms and at idle I have about 4ms. As we go with it we will adjust the Dwell to best saute the conditions.

There is lots of info out there on LS coils and its a great resource. From most the testing I have seen the LS1 coils are in the sweet spot around 4.5-5.5 ms at 13 volts. Any more than that you start making more heat and the benefit is marginal.

Jeremy

 

[IJ.]

So with dwell in mind how far can the stock JZ coils be pushed before they overheat? I currently have my dwell set at 3.5ms under all conditions. Would it be safe to bump it up to 3.75 or 4?

There is usually quite a bit of overhead in the coils but I don't have specific numbers for your coils, keep in mind driving them that hard all the time will reduce their lifespan.

 

[MK-111]

iirc the factory map sensor only works upto 17psi as well,
so using the factory ignitor its not unreasonable to conclude that it is at the max of its capability at that level, thats assuming the ignitor does all the dwell
timings itself,
I had a pm off one of the megasquirt guys who was using the 2jz coils with
vb921 IGBT coil drivers, and he was using 3.5ms cranking dwell, and 2.5ms
running, and said he had no problems with them overheating, or any issues with missing. but I don`t know what boost levels he was running

 

[soapra]

I have JZ coils on AEM and HKS Vpro runing over 30 psi on two different cars. AEM car has HKS DLI and the other has the Vpro with stock coils and stock igniter. We do run a heat rage of 9 on the plug. What heat range do you run Randy? BTW coils are 14 to 15 years old.

 

[becauseican]

I normally run BKR7E's but I am getting tierd of swapping them out every few weeks. I think I am going to try the LS coils on my car, now I just gotta find some.

 

[soapra]

Randy,

The BKR7E plugs are to hot, also the plug is a non resistor plug. Try the NGK iridium in the 8 or 9 heat range before you do change the coils. also iridium plugs are resistor plugs. The BKR7E plugs can cause interference with our ECU's especially at higher boost levels, I've seen weird things happen, like the PC that runs the dyno shut down because of electromagnetic interference.

 

[bfr1992t]

AEM running stock coils needs some kind of amp (HKS DLI) as they are batch fire. In batch fire the stock coils do not have enough charge time and leads to a weak spark.

If you want to keep stock coils spend the $400 and get new coils and a then a HKS DLI do not be cheap and look for lame band aid fixes.

Funny, I consider having to add an ignition amp a lame band aid fix to the shortsighted design of the AEM EMS. Better to mod the AEM EMS for sequential.

I do agree that the OP's plugs are the wrong choice, however 7 is COLDER than 6 and BKR's do have resistors. BCPR6ES works great for me and many others. Do not switch to a colder plug until you have evidence that you actually need to.

http://www.ngksparkplugs.com/techinfo/spark_plugs/partnumberkey.pdf