Ls2 Coil On Plug Mod

[STATUS]

With genuine OR decent aftermarket LS coils.. what spark gap & boost are you guys running?

I'm running Splitfires with 0.65mm gap at 3.5ms dwell and they're blowing out at 1.5bar+ when warm..

I started off at only 2.8ms dwell but kept on adding more to stop the misfiring - however it seems to start misfiring after a 20 minute drive even with high dwell. I don't want to push them any higher in case they fail.

I'm really considering converting to LS coils (that was the initial plan but got lazy).

John what ecu?

Try a set of BKR7eix @ 0.55mm for shits and giggles, nice clean idle and should hold close to 30-35psi with splitfires. If your concerned with the outlay try borrow some factory platinum and gap to 0.55mm and test for missfire (the heat range is no good but a few runs wont hurt)

ive done back to back comparos with the eix @0.55mm and a set of coppers @ 0.8mm with ls coils and they were within 1-2kw at 420rwkw.

we use coppers in most things but with ignition missfire prone cars we run the small gap irridiums.... you dont want to go as low (gap) with coppers as they dont idle or low load cruise as nice.

[Dose Pipe Sutututu]

Hey Trent, using an Adaptronic ECU with a Hypergear SS2 self tuned. I initially thought I had too much/too little timing and that caused the misfire but with less/flat timing around that area or more it still made no difference. Reference at 1.6bar 3900rpm onwards I've only got 16 degrees of timing and it increases to 18 by redline. Very lazy timing ramp.

I've read and seen with the EVO boys when not enough timing is used with E85 their cars would misfire and or knock. I'm putting my bets against E85 having a slower burn hence it needs the advance to ignite properly.

I'll definitely give the platinum plugs a try with that gap!

However I do see you're recommending 7 heat range plugs, I'm still using 6 based on the understanding E85 doesn't like colder plugs. I do however have a spare set of BCPR7ES at home which I could try next (since I've already bought them) before buying the platinum plugs.

[scotty nm35]

I had issues with Denso iridium IKH22's, but NGK iridium 7's seem to last well in mine Johnny. Anything hotter seems to melt in a few thousand. As Trent mentioned, small gaps work well if misfiring, but be careful gapping them down they are brittle.

[PSI086]

yup stay away from the metal heat sink ones if possible i had a few come in from other places with detonation issues and it was because they were tuned with too much dwell.... its a documented fact they have cost guys engines.

we always recommend running the;

C1512

D514A

OEM part 12573190

and are able to run low dwell and up to 1.5mm gaps with boost.

​If you do choose to run with the inferior truck ones just make sure you keep the dwell in check.

Just wondering what you usually dwell these coils at?

Edited September 27, 2014 by PSI086

[Scott Black]

im pretty sure the ls2 coil is around the 5ms dwell time

[r33_racer]

I run the ls2 round truck coils in my race car at 5ms dwell no issues, that is with coil near plug on ls1.

I believe the d585s are the strongest output oem coil you can get. Im sure I read somewhere that GM made them for flex fuel suv's/trucks which explains the output and why they are the most sought after when upgrading ls ignition systems.

Edited September 30, 2014 by r33_racer

[STATUS]

5ms is really flirting with danger. 4.5 @1000rpm and 4.2 peak rpm at most is safest.

At 5ms we noticed definite issues with some when ignition was strobed at a crank level.

Factory coils are also dwell limited (updated factory calibration) for this reason.

[Ben C34]

Trent, when running nistune how are you adjusting the tables to get the correct dwell.

As you would know it's not as straight forward as different ecu's.

I found I had to modify both tables to get it acceptable, but even then the ecu does some weird stuff with the dwell (reducing it) on a series 2 stagea. Matt seems to think only the voltage correction table needs adjusting.

I appreciate your time sharing what you have found so far.

Ben

[r33_racer]

Interesting. I will definitely look into it. May need to set it lower if that is indeed the case!

[mojorick]

The GM D585 coils are perfectly safe when dwell is kept below 4.0MS. There are numerous 2jZs in the US successfully running boost in the 40s at 3.4 MS dwell with the truck coils. Out of several hundred users of my 2JZ coil-on plug kits, I have had reports from only 3 having misfire problems caused by coils.

The overdwell timing drift is well understood - I have personally seen blown engines, both 2J and RB from this cause. It does seem to be ECU type dependent, as I ran 5.0 with my Haltech PS2000 for a year with no issues. (I have since reduced dwell with no apparent detriment) The failures I've seen are with Proefi and AEM. The upshot here is that there is no need to go above 3.4 with good coils, good tune, and no other problems.

There is some evidence that some coils misfire due to overheating - I'm investigating that now.

[Dose Pipe Sutututu]

slightly related, however related to my previous posts.

I've taken Trent's advice and gapped my new set of plugs down to 0.55mm and running 7 range plugs - idle noticeably not as silky smooth but at least it's not spluttering. At 1.6bar there's still a little breakdown, which I am thinking could be coil related.

Then last night, I was going through my logs.. I noticed something VERY strange.. my voltage (recorded at the ECU) is around 13.6V on idle which is good however each time the car comes on boost the voltage falls back close to 12.1V - now that can't be good.

This could be the very reason why I keep getting misfiring issues with whatever dwell setting I've set.

Next is to replace my alternator and see if it goes away

[omnigear]

why not test the alternator before changing it to see if that is the actual problem?

slightly related, however related to my previous posts.

I've taken Trent's advice and gapped my new set of plugs down to 0.55mm and running 7 range plugs - idle noticeably not as silky smooth but at least it's not spluttering. At 1.6bar there's still a little breakdown, which I am thinking could be coil related.

Then last night, I was going through my logs.. I noticed something VERY strange.. my voltage (recorded at the ECU) is around 13.6V on idle which is good however each time the car comes on boost the voltage falls back close to 12.1V - now that can't be good.

This could be the very reason why I keep getting misfiring issues with whatever dwell setting I've set.

Next is to replace my alternator and see if it goes away

[Dan_J]

Next is to replace my alternator and see if it goes away

check charging voltage at battery first and then check at the terminals on the alternator, this will tell you if your wiring has been chewed through over the years like mine was.

if alternator works fine run and 'T' a 30-40amp wire from battery to the positive main wire on the coilpack loom with a relay and 30-40amp fuse

[etang789]

There is no need to push the D585 into the timing drift areas with big dwells. Safe sub- 4.0MS dwell numbers have supported over 1000whp.

If you use the LS2 coils below 4.0ms dwell numbers is it still considered to have much more power than Stock OEM or Spitfire Coils?

[Ben C34]

How much below?

Stock dwell they are worse.

[BLITZ-26]

i see alot of info with the nistune, but is there more ability to use these with a haltech platinum pro ?

i am very interested in setting this up

[Ben C34]

i see alot of info with the nistune, but is there more ability to use these with a haltech platinum pro ?

i am very interested in setting this up

All you need to be able to do is adjust the dwell. Any aftermarket ecu has that ability.

[etang789]

How much below?

Stock dwell they are worse.

Around the mentioned safe dwell level 3.5~4.0ms

[Ben C34]

Substantially better. But probably not required.

[Dose Pipe Sutututu]

I wonder if this has massive effect on my misfiring issue