Ls2 Coil On Plug Mod

[rickskylinebnr32gtrjp]

Photo of the Mojo harness/kit:

[rickskylinebnr32gtrjp]

The wiring from the ECU side (firing order) that was given to me in the Mojo kit instructions looks like it's wrong. I'm going to test it shortly to see if what I found checks out. I guess I should have looked before cutting wires.

[Ben C34]

The wiring from the ECU side (firing order) that was given to me in the Mojo kit instructions looks like it's wrong. I'm going to test it shortly to see if what I found checks out. I guess I should have looked before cutting wires.

Sounds like you are on the right track.

I know that with stock dwell ls coils misfired at 15psi plus with me. Below that no worries.

Once dwell sorted they are sweet as!

[Rbdirty30]

Would it be worth buying the msd ls2 coils? Or are the factory Gm coils just as good?

[mojorick]

Oops, This was my first production Series 1 harness and my instructions were wrong - Mirror imaged the igniter input connector .

Looks like it's straightened out now.

rickskylinenr32gtrjp, Let me know how this works for you.

[mojorick]

I have not tested the MSD coils - But so far have found no aftermarket items that match the spark plug current provided by the OEMs.

Accel also makes a D585 copy that I intend to test when I get the time.

[rickskylinebnr32gtrjp]

Good to go! Started right up faster than my old Splitfire coil packs and no throttle modulation on cold start like I used to have to do to keep the idle from dying before warming up. That's impressive. Going to take the car out for a spin in the next day or two to see how the boost holds up with stock dwell.

Regarding the aftermarket coils, it is my understanding that there are varying qualities and while pretty much all of them are made in China, many of the OEM's are also made in China. The coils I bought are made by Araparts and they seem to have a decent reputation and on Amazon most of the reviews for these coil packs are "5" with only a few "4"'s. I should find out soon enough if the aftermarket ones can't stand up to the abuse.

Rick B: Do you have any specific test data or videos that I can look at to see what you're referring to?

[scotty nm35]

It is interesting all the Toyota and Mitsubishi guys swear Yaris coils are the go, yet RB owners are unwilling to try anything other than these tractor coils...

VQ coils are where it's at for Nissan engines.

[mojorick]

scotty, Toyota Guys in the US (and in Australia) are increasingly using the GM truck (not tractor) coils. There are about 400 of my kits out in the worldwide Supra community. They are built with an igniter (not just a simple switch transistor) that can build charge much like a CD amplifier. This enables the use of increased dwell for more output. I have also verified that the D585 produces more plug current than the stock 2J coil given the same dwell, even using the HK$ DLI. These coils were put on flex fuel vehicles and were designed for increased spark power. The genuine AC Delco D585 coils are mostly made in Mexico.

Rick, I have done some coil testing using a current probe and an oscilloscope to monitor output current, in addition to looking at igniter current across a shunt resistor. These two measurements give some insight into coil saturation point as well as ultimate spark power. My cheap current probe does not deliver values easily translated into amperage, but does make an excellent tool for comparisons. I am a retired test engineer, and still love this geeky stuff. Just wish I could afford better equipment.

The link shows comparison between the GM D585 and the Toyota 2JZ- GTE coils with DLI box. I was trying to test the 1ZZ coils (same as the Yaris I think) but they didn't like the shunt resistor so those results are not valid. I did later verify that the 1ZZ provides about the same spark output as the Supra TT coils sans DLI.

I have similarly tested several "parts store" type coils and found that none of them provided the performance of the "real' D585s.

I do plan on doing more testing with better documentation when I get time, especially interested in the MSD and Accel parts.

http://www.mojoperf.com/drupal/node/17#overlay-context=user/1

Edited December 9, 2014 by mojorick

[rickskylinebnr32gtrjp]

So the real D585's are made by AC Delco, right? I just want to be sure so I order the right set.

[mojorick]

If it's the GM part 10457730 ( and actually has that number on the box) , That's the genuine AC Delco D585. Lots of cheap AC Delco BSC-1251 on ebay, advertised as D585/BSC-1251 - Made in China. I actually ordered a set of these and tried them on a customer car - on the dyno they worked fine until about 20 psi, then started to misfire. My bench test confirmed that they just don't deliver the plug current of the OEM part. I contacted AC Delco the see if this was a real branded part, and they confirmed that it was - a lower cost, lower performance coil.

Tons of these in American junkyards - the used coils have been super reliable in the field.

[XKLABA]

Have you tested any of the OEM Honda coils, my tuner swears by then and suggested me to upgrade to them on my BNR34

I currently have the splitfire coils rewired to get direct current from alternator and at 28psi I run out of spark

I am using Denso IQ24 plugs, if it makes any difference

[scotty nm35]

Pointing an oscilloscope in the general direction of the output of a coil won't tell you the full story, coil efficiency and voltage output would perhaps be a more important measurement. I like to test things like this in the real world, no amount of bench testing makes up for a good hot load test at high boost and running rich.

Personally the timing drift associated with mucking around with dwell on these scares me. I would prefer something that just drops in and allows 40psi at 1.1mm, like the Yaris coils apparently do. I will give some real world feedback on them soon seeing they are in and running fine on my evo.

After running my original 13 year old VQ coils to 40+psi I have great respect for them, I don't suggest them for any other reason other than they work, I have nothing to make out of it...

[mojorick]

XKLABA, I have not tested the Honda coils - Maybe will take a look next time I set up the bench.

scotty, Even if you could understand the test criteria I use, I doubt that it would change your made up mind. The testing I did was mainly to compare two known good systems as used in the 2J world. It was not meant as a substitute for real world function, which incidentally has supplemented and validated my testing hundreds of times over.

The overdwell characteristic of the truck coils is well documented and is totally in control and safe by correct EMS setup.

I have seen many of the local Nissan guys using the VQ coils with good results.

Sorry I called your baby (Yaris coils ) ugly....

Edited December 10, 2014 by mojorick

[etang789]

Oops, This was my first production Series 1 harness and my instructions were wrong - Mirror imaged the igniter input connector .

Looks like it's straightened out now.

rickskylinenr32gtrjp, Let me know how this works for you.

So I can purchase your kit with the harness now?

[XKLABA]

What about the complete kit ?

Do the Delco coils have inbuilt ignitors ?

[rickskylinebnr32gtrjp]

What about the complete kit ?

Do the Delco coils have inbuilt ignitors ?

I'll let Rick B answer your questions about the kits available.

As for the igniters, yes, they are built into the D585 coils.

[rickskylinebnr32gtrjp]

Okay, so I just tested my "parts store" made in China Araparts D585 coils and I have to say that I am pleasantly surprised that it ran a full 32psi of boost with no misfire. Although, I didn't do a full run through all the gears to redline, I thought if it was going to break up at all I would have seen or noticed it. Now, I haven't talked to my tuner yet about changing the dwell so I assumed that my HKS FCon V-Pro was still set at stock dwell settings. I'm thinking that either the dwell was already increased with the Splitfires that were in the car before or the HKS ECU is doing something that I don't know about.

[etang789]

is it better to use a relay and directly connect to 12v power?

[Scott Black]

for stockish application providing the coils are in good condition the 2500ms or so dwell the factory ecu uses works well, at 3000ms dwell at 15psi on stock turbo and stock engine they can ignite a richer than 10:1 98 ron fuel mix at 7000rpm that the factory coils couldnt. ( this was before tuning the car hence the stupidly rich mix from a ecu basemap)
and for what its worth it would idle and free rev fine at 500ms to lol. (small mistake in entering updated dwell on ecu)