LS2/ D585 Coil Dwell
 

I know this topic has been beaten to death. But I'm finding conflicting information.

I'm running the stock ecm on a Racing Beat street Reflash.

Do I need to absolutely change the coil dwell setting to run D585 coils? I understand that maintaining the maximum potential of them would require such, but is there an improvement over stock coils with no dwell changes?

I've read that the BHR harness eliminates this from being an issue. However I've seen BHR post saying it's not necessary to change the dwell time unless your flowing over 300 gms/sec.
I haven't logged my car since I had my engine replaced - but back then I was flowing 220gms/sec prior to engine replacement.
I don't plan on going FI.


And onto the flame. I'm making my own PnP harness, bracket, getting D585 coils, making my own plug wires as well. I'm totally competent to do such. (Been in the automotive business for 5 years, working on cars since I was 15 - not that it matters)

If someone is just going to step in here and say "it wont work". Elaborate. Tell me why it won't work, give me specifics. I've found a few threads of people making they're own kit, but no real follow up if it worked good for them or a lot of talk about coil dwell.
(Aside from Mark telling me about re-working the coil & help from olddragger)

made my own kit, works fine, can't adjust dwell settings because i have an S2, car hasn't blown up yet

Did you notice any improvements? If so were you coming from having issues? Carbon'd plugs, weak coils?

On a side note I picked up GM pigtails and the connectors for ~$60. I also pulled like 10 feet of wire sheathing out of a used car that had computers in it for airport parking ticket enforcement. I even kept the wiring cause it looks VERY high quality WOOT! haha.
All said and done the harness should look legit as OEM. I even got a huge aluminum plate out of it and some aluminum brackets I could probably use to make my own coil bracket. I'm not a fan of how the long bolts bracket looks.

Hey man, I think that if you're planning on doing this then go a head and go through with it. It's generally impossible for people on this forum to come to a consensus because of all our differing opinions, which often times makes decision making hard. But I'm sure you know that by now :lol2:

Personally I think that if you were running 220 before you rebuilt, then you probably aren't running over 300 now. I don't know much about D585s but I would say not to mess with the coil dwell time at first, look for improvement, and if you aren't satisfied maybe mess with it then. Ultimately it all comes down to what you're comfortable with, because it's your car and your work. I don't see anything wrong with your solution, and I'm interested to see your followup on how it worked for you.

No. The principal unambiguous improvement of doing so however, will be greatly increased reliability and coil lifetime.

Yeah I don't have a cobb, so I won't be messing with it anytime soon. Exactly my point though with only pulling 220. The car did/does feel much better though! It'll be interesting to see once spring comes around what I can log with my matco scanner.

I plan on updating this thread with continuing developments on the project. A lot of people seem very interested in this and I'll likely have additional parts/pieces left over for an additional harness.

Agreed. That is another reason I wanted to go this route is to not have to worry about rolling up on 30k miles with OE coils and questioning their functionality. I'd rather have reliable coil performance/longevity accompanied by piece of mind that I'm not going to get random misfires; though I have been lucky last spring/summer with the car running great and maybe only getting one misfire event. I do plan on routinely checking/changing out plugs though too.

There is this option. The coils typically cost more, but you get much more spark with OE dwell. The wire sizing is not an issue at OE dwell either.

https://www.rx8club.com/tech-garage-...-coils-221536/

Good info minus the on going children's play and nit-picking.

I would explore that route, but I'm trying to be somewhat cost-effective since I'm looking at buying a house in the immediate future. That and I already forked over cash for the D585 coils.

On a side note - I completely agree that the OE wire sizing wouldn't be much of an issue in a stock or lightly modified application(like mine), but toss in there some corrosion to spike some high resistance and I wouldn't be so sure.
I peeked at the OE grounding location that has a connector on it and it is rather small. I plan on potentially using a good 10 gauge wire for grounds since that should be plenty to stand up to environmental conditions/ time and a bit of "breathing room" per say. Giving the GM wiring 10 gauge for it's own ground as redundancy will just put a nail in the coffin(I feel anyway)

**Update**
So I found REALLY good pricing for building spark plug wires at Welcome to Race-Mart - Quality isn't an accident
Just called summit and they price-matched them no problem for $73 shipped. Not too shabby.
Prices may be found cheaper. I went with summit cause they ship from Ohio so I get stuff in 2 days, and have excellent customer service should there be an issue.

MSD -34039 (x2)
Taylor -46069 (x1)
Taylor -46061 (x1)
Taylor -43390 (x1)

Ok that is an ass-ton of wire (unless you gave the wrong number, 34049 is their 100' spool of 8.5mm)

Dont forget to get your hands on some dielectric grease and more importantly wd40 or else you are going to have a shitfit trying to slide on the boots.

I have that same crimper, does a good job, but FWIW it will loose its alignment after a few uses (no biggie unless you plan on making like 20 sets of wires with that 200' of wire you ordered lol)

you might want to rethink throwing the nitpicker card around like a rock in a neighborhood full of glass houses

12 feet should be enough of wire (see summitracing). Yep I got access to all that at work. :yesnod:

Mark, I think you took that comment as an insult towards you. However it was not. Instead it was rather directed at BHR & MM making childish remarks to be "politically correct".
I mean seriously guys. There is more important things in life. But I don't want to get off topic and start a pointless bicker back and forth. :dunno:

12 is plenty, thats what i used. But the number you gave was for the 100 feet bulk pack lol.

MSD 8.5mm Super Conductor Wire Rolls 34049 - SummitRacing.com

Pretty sure you meant 34039 ;)

Whoops! Fixed!

I have had experience with these coils on OEM dwell , MMs' recommendations and more lately the 'correct' dwell .
On stock dwell I believe they are under charged but still sufficient to provide similar spark to the stock coils while lasting a lifetime. Starting performance over stock (good) coils is diminished ,however most people wont notice this.
With the 'correct' dwell they are a significant improvement over the stock coil in all conditions.

I'm too lazy to research, but what are the dwell settings you speak of here?;)

I'd be interested for future reference of when I may potentially pickup a Cobb.

apparently you didn't realize I was only joking, guess I should have included the ---> :cwm27:

check the last few pages of this thread :


https://www.rx8club.com/engine-tunin...ssport-178635/


Read the whole thread for some good entertainment and history

/\ search faster next time LOL

except that I linked directly to my specific post 8 pages in

I think grabbing a cobb would be a worthwile investment, and feel free to sell me those leftovers! :naughty:

Confucius say, man who live in glass house... should change in basement.

dont forget to mention the msd 8247 coils that are also designed to work with less dwell.
Just saying..............(flame suit on)
They are more expensive.

They actually perform worse than the D585 with OE dwell, especially on startup

findings on that?
Mine, to date, have perform flawlessly. Cold start, hot start etc etc--np's,my plugs look great.
I do run the oem dwell (for people that may not know)
The Ig Mercury coils (? proper name) were my second choice and only because I was not familiar with them at the time, but the msd's have been great not only for me but for another member as well.

mine started cold fine, but then not warm

got a set I'll let go cheap if you know somebody, been sitting in a box for four or five years

i will ask around and let you know. I may know someone here in Ga.

**Update**
Made my first PnP harness. Im not sure if I want to explore a different wire sheathing just yet. The connectors look perfect. Right now I left the common ground out to tie all together. I just want to verify the pins on the Mazda harness before I go nuts and make em wrong. LoL

Attachment 228584

It would help people to know what you are using for the OE harness connectors.

Verified the pins so I can go crazy making my harness.

I was going to wait to provide a link but here ya go.
http://www.spoolinup.com

http://www.szabaga.com/store/images/IMG_1972.JPG

Imagine that, we share parts with EVO's lol just kidding. They all use similar connectors for asian import manufacturers. After doing some digging I found this place, owner is super cool and ships fast with good communication.

Go to -> Products -->DIY EVO Parts, Sensors, Connectors --> Connectors.
I chose to go with the 8th one down, however the 9th will work as well.
Note: Crimping these are a bitch with a regular crimper. I soldered mine in place so I'd go with the solder ones in hind-sight. This way no wires will pull out or become loose.
A little bit of dielectric grease or silicone paste on the little yellow insulators help pull them properly into the connector. I'll upload some more pics of this when I make my next harness.
http://www.szabaga.com/store/images/IMG_1969.JPG

At this point I just kind of picked a length I found suitable for mounting my coils in the OE spot, while still having some wiggle room in case things were too short.

The GM pigtails I sourced from auto wiring solutions on ebay.

The wire sheathing I had gotten for free, like mentioned prior but a good business sells similar high temp stuff here. I'm sure you can find it other places, but they're local to me and ALWAYS have every fitting in stock. https://www.pegasusautoracing.com/pr...GroupID%3DWRAP

So as of right now the harness looks great. My only concern is the depth of the pins for the OE Mazda male connector. They appear to be pretty shallow but I will verify this when I can get access to an RX8(either mine or the one I'm working on).
Stay tuned for an update on the connectors.


Making the pins and PnP harness is quite easy but you need to pay attention to detail.

First cut the harness to desire length. BEFORE you strip the ends, put the weather insulators on the wire and run them back so they don't get damaged.
Strip approximately 1/4" of wire. (This is important because if your wire is too long it will stick past the first crimp area and block the 'lock' for the connector housing to keep the pin in place.)
Run the little yellow weather insulators to the edge of the wire insulation.
Should look like this.
Attachment 228578

Wire inserted, note the crimp locations and wire length.
Attachment 228579

Next Crimp down the two stages. I did the forward most to the pin first to ensure the wire wouldn't block the 'lock'. Then crimp the second for added security/rigidity. I didn't like crimping these, nor do I trust the crimping tool mentioned in my previous post for doing small wiring like this. I soldered them in place. NOTE: If you're not good at soldering your going to have buggers/"slag" left over, you need to file the backside of the pin to get a smooth surface and ensure the pin slides into the connector with NO interference. Shown here is the soldered wire, note the insulator isn't crimped yet. Make sure you crimp this connection evenly since this also will not allow the pin to enter the connector.
Attachment 228580


Wire up the rest of your pins.


Next slide on your wiring sheathing/protection of your choice. Insert them into they're according pin locations. I did this by inserting them by hand and GENTLY pulling them through with a small needle nose. Once they are through take a small pick or pocket screw driver to push the lock into the locked position and GENTLY pull the wire out of the connector to lock the pin in place. Double check its locked by GENTLY pushing on the pin from the connector side to make sure its not going to back out.
Patience is the key, DON'T force anything!

The end result is pretty PnP harnesses. My LS2 coils arrived just in time as i was completing the last harness.
Note the ground wire is left unfinished to find a ground location to my liking with the extra amount of wire left over.
Attachment 228581

Good job......tip though :).....the correct crimp tool saves you a lot of work :)

I did just try the Taylor crimper (which arrived after I made all my harnesses) and it does work quite well. So for those who aren't experienced with soldering still have the option of using the crimp connectors.:icon_tup::D:

Proper crimp is better than solder ( can't believe I'm saying that :), I've been a crimp and solder guy for 20 yearrs) but it is true.

Solder joints on connectors make the joint much more susceptible to failures from vibration, and don't improve the connectivity if the crimp is good

Yep, I do agree with that statement. However I feel the difference would be negligible in terms of amperage and resistance. (At least in my application)
Most OE manufacturers went away from soldering in repairs because of that and because most people were never taught how to solder properly. They'd booger up a connection and result in high resistance, or not weather-proof it properly and it'd be overly susceptible to corrosion.

This way the joint will never come loose/ have to worry about it. If I had that Taylor crimper I probably would've just done it that way since it is much faster. :D:

You in the auto/ wiring business too Dan?

LOL...no :)

30 year hobby

the only reason it is not a business of Dan's is because he is not getting paid for it--lol! Like a lot of us....

Temporary mock bracket made. I grounded the coils to the bracket to keep things simple and somewhat clean. This way there isn't random wires running everywhere. Just gotta mount it in the car yet and make adjustments.

Attachment 228537

Original bracket idea is scratched. Way too big, and ugly IMO.

Got some aluminum strips bent to conform around the individual coils so each has it's own singular bracket to mount to the existing coil studs.
Probably will have an update around spring-ish since I'm in the process of buying a house so this project will likely go on the back-burner.

UPDATE on the pin depth.
The depth will work okay. I measured resistance and they're all less than 1 ohm back-pinning the GM harness to the OE harness in the car.

nice to have a clear brief answer about the dwell settings. should be a sticky somewhere.

at the risk of sounding like a BHR fanboy, haven't you spent a lot of time and money to recreate the wheel here..?

Not really. I don't ever like paying someone for something I can do myself, especially at that high of a price. I've been fabbing stuff up in between "lulls" at work. I guess some people just want to install parts - understandable, some things like an intake, or exhaust I gladly pay for, but simple brackets, a wiring harness, and spark plug wires are not difficult to make.

Time invested: 3 hours or so give or take a half hour.

My running total:
8 Coils with separate wiring (will likely sell the other set and wiring eventually) $140.
GM pigtails $38.50
Mazda connectors $33.00
Spark plug wiring $73.18
Wire sheathing: $0 (See post above for link to similar stuff)
Brackets: $0 (Can be purchased at local hardware store for less than $8)

Total: $284.68

Sub $300 was my goal. Add in the reduced overall long-term cost by selling the (2x) sets of GM pigtails, and the 4 other coils(given all 8 coils work good), and it should easily be under $200.

They enjoy paying $500 + shipping to avoid reinventing the wheel and get fancy colors

I used a piece of aluminum U-channel and tie wraps to hold them together as an assembly, then a big tie wrap to hold them down on the factory mount. It's light, simple, and does the job. It sounds ghetto, but you can't really tell it is anything more than a set of four coils sitting in there.

I still hate the special GM coil-plug wire connector. If you lose a plug wire for whatever reason you can't just go to the parts store and buy a generic one to get you by. Maybe not that big of a deal for a street car, but not so great for a competition car. I made a long spare wire assembly just in case for that scenario.

I found a few local suppliers at the whooping price of $30 a pop. Yeah no thanks!!

I have never had any issues with the MSD coils.

/did not stop me from buying spare coils when I thought I had coil issues...

/sigh

I'm trying to be a bit overly analytical about this topic, I've spent hours upon hours reading/searching. My question is related to the initial question in this thread. I understand that the D585s will work with the stock ECU and that it's the most powerful of the LS2 coils and possibly the most reliable. However, if there are potential hot start issues and it's more optimal to adjust the dwell with a aftermarket solution, is there a better LS2 ignition for those running the stock ECU? All of the LS2 coils are powerful, will any of the other avoid this issue and perform like the OEM Mazda coil, only more reliably?

Here are the options:
D580 Corvette Coils (LS2)
D581 (12558693) Truck Coil
D585 (10457730-Delco, 19005218-Delphi) Truck Coil
D513A (12570616) LS2/LS7 First Design
D514A (12573190) LS2/LS7 Second Design
Megasquirt Sequencer Coils

I don't really understand the difference between the D581 and the D585. If they're applicable for the same models of vehicles, why are both still available (why hasn't the D585 superseded it)?

Comparison of LS2 d580 and D585 coils. The D580s appear to be "fine."

Brand does seem to matter: AC Delco D585 vs. generic:
Toby Lawrence - YouTube
VWVortex.com - LS2/Yukon coil conversion

Also, does anyone know if there is a difference between the "Delphi" LS2 coils and the AC Delco? Sometimes Delphi manufactures parts for AC Delco, sometimes it's someone else, I don't know which is it in these LS2 coil cases.

Being that no one has made a solution for this other than adjusting the dwell time via mapping - I don't think so. Even so you will have a slight gain in overall performance by adjusting the dwell time. The hot start is the only issue I've heard of when running OE dwell.

It appears BHR really did the homework here on testing other coils and found the D585 to be optimal. It wouldn't be cost effective to start the project over in the mere hope of some cost savings (which would actually be the opposite in this case of trial and error/ "R&D")

Again, really unnecessary to chance it when it's been proven to work on multiple applications. The D581 is a different coil appearance wise.


That has been a huge talking point throughout. I decided to go with 8 used GM coils in an effort to be cost effective. I didn't want to spend substantially more on new junk coils that don't perform like shown in the video. Nice video BTW.


Likely it is the same manufacturer. I found in parts shopping you wanted to select the delphi equipped ignition though.

Tried a different mounting solution. I need to trim the OE studs to get things situated better. But here's the idea anyway. Still unfinished but close - now that I got them mounted in roughly close I built my spark plug wires with only one 6' package so I have even more savings once I sell the extras off.
Pics! Again, still unfinished. The rear rotor coils had to be turned, and the fronts had to be angled due to the studs and brackets. The OE harness is very close, but can be moved so my PnP harness will take up it's current location. Again the Grounding wires will be grounded to the OE bracket.

Attachment 228441

Attachment 228442

thats an interesting way to do it....

i opted for an easy and less expensive solution:

https://www.rx8club.com/attachment.p...ine=1357320679

https://www.rx8club.com/attachment.p...ine=1357320679

these pics were before i cut off the square in the bracket that was used to hold the oem mains harness, and the little tab on the right that was used for the oem wire guide.

btw, there is a reason why you want the coil output to be away from any metal ground (i.e. the engine block) .... i personally wouldn't leave my coil turned over like you do in that last pic.

Almost everyone is running the D585s. They're obviously better than OEM in many ways and the most powerful LS2 coil, but it's without additional information it's difficult to say if the dwell differences vs. OEM are better/worse/same. I'm hoping someone has some of this kind of information. Just because people think something is "fine" it's difficult to say if it is the most optimal in all situations. Anecdotal experience is further complicated because these aren't exactly the most reliable cars. :)

My questions are primarily not to do with cost savings, it's about understanding the full picture.

There are some things you discover for yourself , after which you know absolutely 100% what the answer is .
Despite all claims from happy owners that hot starting on 585's on stock dwell is better than oem, I KNOW that (compared to good oem coils)..... it's worse !If you want a detailed account of why I'm so confident of this fact I'm happy to give it .

And BHR doesn't have to come in and defend their product here - it's still a great product and the best after-market coil kit available .

However : Forums like this should tell people the full story and it irks me immensely when things are hidden from the public domain.