New NGK BKR9EIX 0.028" gap installed now random misfires idle and low rpm...

[01northernS4]

5 minutes logging saw single digit misfires across all cylinders low rpm and idle once warmed up. Runs great otherwise. Didn't log any misfires at wot and higher rpm under load.

On a positive note logged to be boosting 1psi higher and shifting 1000rpm higher... strange she feels stronger at wot and under load... snappier and smoother.

Dual pulley unitronic.

Was on stock NGK platinum 8s at 0.030 to 0.032 gap no misfires.

Thoughts?

Reduce gaps or drop to original stock heat range?

[awwturbo]

I used those plugs on my setup and they didn't work really good. Unless you are an extreme pulley ratio in hotter climate I would stick with OEM plugs at a 0.026 gap. That works the best for me.

[01northernS4]

I used those plugs on my setup and they didn't work really good. Unless you are an extreme pulley ratio in hotter climate I would stick with OEM plugs at a 0.026 gap. That works the best for me.

I know, and against my better judgement and all I've read here I went with Unitronics recommendation as I trust them and they are known for thorough testing as well as being in Canada like myself soo cold climate eh, lol... now I just have to figure do I re-gap the 9s lower or bite the bullet and go to 8s iridium or stock 8s platinum...

Unitronic stressed the choice is due to the need to pull more heat out of the combustion chamber.

Reason I posted this is under load or WOT I logged NO misfires and she seems to run stronger than before... it's just a little unsettling to see single digit random misfires over 5 minutes of logging when warm at operating temp and only at low rpm or idle when there were none before on the old stock plugs and gap... seems strange... do I ignore or try to regap slightly lower to see if I can eliminate them?

Thanks!

[MSq5]

Stock heat range (8) is still best for DP Stage 2 and 93 octane. Gap them down to whatever Unitronics recommends - probably .026".

Always run the hottest heat range you can that does not pull timing to avoid detonation. The low rpm misfires are going to eventually foul those plugs.

[01northernS4]

Stock heat range (8) is still best for DP Stage 2 and 93 octane. Gap them down to whatever Unitronics recommends - probably .026".

Always run the hottest heat range you can that does not pull timing to avoid detonation.

thanks MSq5, that's what I thought... some posted here that unitronic recommends 0.025" but I called to confirm, twice, and they said 0.028" which is what the ngk 9 iridium comes at

maybe I should gap down a bit or ignore the single digit random misfires at low rpm and idle (scratch that, just noticed where you said it will foul the plug)

is it normal she seems to run strong so far under load and wot, no misfires... only at low rpm and idle when warm?

would you go stock heat range 8 ngk platinum or iridium despite unitronic recommending 9s iridium at 0.028"?

Can something like this settle in, and takes a little time to break in? don't want to jump the gun

thanks again gentlemen

[MSq5]

thanks MSq5, that's what I thought... some posted here that unitronic recommends 0.025" but I called to confirm, twice, and they said 0.028" which is what the ngk 9 iridium comes at

maybe I should gap down a bit or ignore the single digit random misfires at low rpm and idle (scratch that, just noticed where you said it will foul the plug)

is it normal she seems to run strong so far under load and wot, no misfires... only at low rpm and idle?

would you go stock heat range 8 ngk platinum or iridium despite unitronic recommending 9s iridium at 0.028"?

FWIW, I'm running the NGK Iridium 8BKREIX gapped to .028". No misfires. But, my tune is EPL. See below. If Unitronics recommends 9s at .028, then check your actual gap with a feeler gauge. Do not use a coin type gap tool. Be very careful gapping iridium tip plugs. Don't scrape the tip or pry against it. Very easily damaged.

[01northernS4]

FWIW, I'm running the NGK Iridium 8BKREIX gapped to .028". No misfires. But, my tune is EPL. See below. If Unitronics recommends 9s at .028, then check your actual gap with a feeler gauge. Do not use a coin type gap tool. Be very careful gapping iridium tip plugs. Don't scrape the tip or pry against it. Very easily damaged.

good to know and understood... I am running the recommended 9bkreix at 0.028" as per unitronic... just need to either drop the gap, go stock platinum 8s (since I didn't have this many misfires at idle and low rpm when warm on them) or ngk iridium 8bkreix (1 range warmer from where I am now)

can the 1 range warmer actually eliminate the low rpm and idle single digit random misfires when warm (clean soo far under load or wot)? or is it more of a gapping issue (reduce it from 0.028")?

[awwturbo]

I know, and against my better judgement and all I've read here I went with Unitronics recommendation as I trust them and they are known for thorough testing as well as being in Canada like myself soo cold climate eh, lol... now I just have to figure do I re-gap the 9s lower or bite the bullet and go to 8s iridium or stock 8s platinum...

Unitronic stressed the choice is due to the need to pull more heat out of the combustion chamber.

Reason I posted this is under load or WOT I logged NO misfires and she seems to run stronger than before... it's just a little unsettling to see single digit random misfires over 5 minutes of logging when warm at operating temp and only at low rpm or idle when there were none before on the old stock plugs and gap... seems strange... do I ignore or try to regap slightly lower to see if I can eliminate them?

Thanks!


thanks MSq5, that's what I thought... some posted here that unitronic recommends 0.025" but I called to confirm, twice, and they said 0.028" which is what the ngk 9 iridium comes at

maybe I should gap down a bit or ignore the single digit random misfires at low rpm and idle (scratch that, just noticed where you said it will foul the plug)

is it normal she seems to run strong so far under load and wot, no misfires... only at low rpm and idle when warm?

would you go stock heat range 8 ngk platinum or iridium despite unitronic recommending 9s iridium at 0.028"?

Can something like this settle in, and takes a little time to break in? don't want to jump the gun

thanks again gentlemen

I wouldn't run the Iridium 9's in the winter. If you have the old stock ones and they are in decent shape, I would put them back in gapped at 0.026". Even if you re-gap the 9 Iridiums, they probably will get fouled up quickly from normal driving like MySq5 said. Never tried the 8 Iridiums so I don't have any insight on those.

[01northernS4]

I wouldn't run the Iridium 9's in the winter. If you have the old stock ones and they are in decent shape, I would put them back in gapped at 0.026". Even if you re-gap the 9 Iridiums, they probably will get fouled up quickly from normal driving like MySq5 said. Never tried the 8 Iridiums so I don't have any insight on those.

Yes, that's what I originally thought and am leaning to... only went this way as that's what Unitronic recommends... too bad as she feel's stronger at wot and under load. but I guess it could be from the plugs being new more than the swap to recomended iridium 9s...

so this isn't something that will settle in and "adjust"?

[awwturbo]

I know, and against my better judgement and all I've read here I went with Unitronics recommendation as I trust them and they are known for thorough testing as well as being in Canada like myself soo cold climate eh, lol... now I just have to figure do I re-gap the 9s lower or bite the bullet and go to 8s iridium or stock 8s platinum...

Unitronic stressed the choice is due to the need to pull more heat out of the combustion chamber.

Reason I posted this is under load or WOT I logged NO misfires and she seems to run stronger than before... it's just a little unsettling to see single digit random misfires over 5 minutes of logging when warm at operating temp and only at low rpm or idle when there were none before on the old stock plugs and gap... seems strange... do I ignore or try to regap slightly lower to see if I can eliminate them?

Thanks!


Yes, that's what I originally thought and am leaning to... only went this way as that's what Unitronic recommends... too bad as she feel's stronger at wot and under load. but I guess it could be from the plugs being new more than the swap to recomended iridium 9s...

so this isn't something that will settle in and "adjust"?

Yea, it could be because the plugs are new that it felt better WOT. I wouldn't think there is an "adjustment" or break-in period for plugs. It should feel good right away since there is not fowling or carbon built up on them new. As they get older there is the decrease in performance because of the carbon build up.

[Silver Streakin]

Now I don't know what to do. I just went UniTronic dual pulley earlier this month (about 100 miles ago) and I'm questioning this too.

I have both sets of new plugs and I'm not sure which to install. UniTronic told me to use the 9 and gap it .025-.028 and said stock was fine until I could get the 9s.

Currently running 25k miles old NGK platinum 8 stock plugs that are probably at .032 and it idles fine and runs great.

[awwturbo]

I know, and against my better judgement and all I've read here I went with Unitronics recommendation as I trust them and they are known for thorough testing as well as being in Canada like myself soo cold climate eh, lol... now I just have to figure do I re-gap the 9s lower or bite the bullet and go to 8s iridium or stock 8s platinum...

Unitronic stressed the choice is due to the need to pull more heat out of the combustion chamber.

Reason I posted this is under load or WOT I logged NO misfires and she seems to run stronger than before... it's just a little unsettling to see single digit random misfires over 5 minutes of logging when warm at operating temp and only at low rpm or idle when there were none before on the old stock plugs and gap... seems strange... do I ignore or try to regap slightly lower to see if I can eliminate them?

Thanks!


Now I don't know what to do. I just went UniTronic dual pulley earlier this month (about 100 miles ago) and I'm questioning this too.

I have both sets of new plugs and I'm not sure which to install. UniTronic told me to use the 9 and gap it .025-.028 and said stock was fine until I could get the 9s.

Currently running 25k miles old NGK platinum 8 stock plugs that are probably at .032 and it idles fine and runs great.

I would take a log and see how the corrections are. If they are reasonable you are good to run the stock plugs. IE also recommends the "9" Iridium plugs, but when I ran their tune a while ago the stock ones ran perfect on the 93 and 100 maps. I wouldn't recommend the colder plugs on a mild dual pulley car.

[01northernS4]

I would take a log and see how the corrections are. If they are reasonable you are good to run the stock plugs. IE also recommends the "9" Iridium plugs, but when I ran their tune a while ago the stock ones ran perfect on the 93 and 100 maps. I wouldn't recommend the colder plugs on a mild dual pulley car.

I did run logs on the stock ngk platinum 8s at 0.32" and they were clean... with no misfires, everything looked great.


Now I don't know what to do. I just went UniTronic dual pulley earlier this month (about 100 miles ago) and I'm questioning this too.

I have both sets of new plugs and I'm not sure which to install. UniTronic told me to use the 9 and gap it .025-.028 and said stock was fine until I could get the 9s.

Currently running 25k miles old NGK platinum 8 stock plugs that are probably at .032 and it idles fine and runs great.

I only went iridium 9s at 0.028" because of unitronics recommendation as I was due for a spark plug change... did you end up calling unitronic again to ask, and if so, what do they say now in light of this?

[Silver Streakin]

I did run logs on the stock ngk platinum 8s at 0.32" and they were clean... with no misfires, everything looked great.



I only went iridium 9s at 0.028" because of unitronics recommendation as I was due for a spark plug change... did you end up calling unitronic again to ask, and if so, what do they say now in light of this?

I haven't emailed back re still running the 8s and it being fine.

I too originally purchased the new 8s because I was due. Then before installing them, I ended up going DP because of my stock heat exchanger was hit, found radiator was seeping on an end tank, and took advantage of the holiday sale since the crank pulley was right there with the rad out.

I wonder if we should be only using 9 if the 8s are an issue. Maybe in the summer heat?

[01northernS4]

I haven't emailed back re still running the 8s and it being fine.

I too originally purchased the new 8s because I was due. Then before installing them, I ended up going DP because of my stock heat exchanger was hit, found radiator was seeping on an end tank, and took advantage of the holiday sale since the crank pulley was right there with the rad out.

I wonder if we should be only using 9 if the 8s are an issue. Maybe in the summer heat?

you may be right but that seems excessive... I mean who is going to change plugs twice a year like winter tires unless you're on the bleeding edge... I daily so I'm not looking to be soo involved.

also, doesn't seem to jive with how unitronic does stuff... they are know to really test their stuff and be reliable as in set it and forget it... I'd be shocked if that were the case as it would mark a departure of how I know them to do business.

That being said, in my other thread about spark plugs, between the poll and posts there it seems stock plug and gap are preferred for dual pulley with a close second being smaller gap on stock plugs

I wonder why Unitronic, IE and other reputable tuners are advising we go 1 step colder plug... I'm going to have to email Unitronic about this and I'd love to hear what they respond to you as well...

[MSq5]

Logs tell the tale. Rule of thumb remains:

1. Run the hottest plug you can that does not pull timing (knock retard) under full throttle high boost.
2. Run the coldest plug you can that does not misfire when gapped properly - a too cold plug will foul under low load low rpm.

These are not contradictory principles. The correct heat range will avoid both problems. For most of us on pump gas and reasonable dual pulley ratios, that is usually heat range 8 and experimenting with gap, usually between .026" and .028".

[01northernS4]

Logs tell the tale. Rule of thumb remains:

1. Run the hottest plug you can that does not pull timing (knock retard) under full throttle high boost.
2. Run the coldest plug you can that does not misfire when gapped properly - a too cold plug will foul under low load low rpm.

These are not contradictory principles. The correct heat range will avoid both problems. For most of us on pump gas and reasonable dual pulley ratios, that is usually heat range 8 and experimenting with gap, usually between .026" and .028".

Thanks for this... so last question for you - since 1. my logs look clean with no misfires under full throttle high boost and 2. I have minimal misfires (approx. 1 to 8 misfires each and every cylinder over a 20 min drive?) at operating temperature when idling or low rpm load... can gaping down these iridium 9s possibly work?

as in will dropping the gap from 0.028"+ ish to 0.026" possibly clear those minimal misfires at idle/low rpm load or is it strictly an issue of too cold a plug, in your experience?

I don't want to go re-gaping if there is no hope and would rather just get the 8s if you knew for sure... otherwise I guess trial and error it is... ugh....

Thanks again MSq5

[MSq5]

Thanks for this... so last question for you - since 1. my logs look clean with no misfires under full throttle high boost and 2. I have minimal misfires (approx. 1 to 8 misfires each and every cylinder over a 20 min drive?) at operating temperature when idling or low rpm load... can gaping down these iridium 9s possibly work?

as in will dropping the gap from 0.028"+ ish to 0.026" possibly clear those minimal misfires at idle/low rpm load or is it strictly an issue of too cold a plug, in your experience?

I don't want to go re-gaping if there is no hope and would rather just get the 8s if you knew for sure... otherwise I guess trial and error it is... ugh....

Thanks again MSq5

It will always be trial and error when it comes to gap. I guess a few random misfires at idle or low rpm is ok, but you may eventually misfire and stumble. Now that you say those few misfires are at idle or low rpm cruising over 20 minutes, I'd not be concerned.

Personally, I'd go hotter to 8s to completely resolve the issue (I did) but, I'm not claiming to be an expert. As to optimum gap, some guys are even using logging of individual cylinders to set gap by cylinder with slight variations to clean up their logs. That's way beyond 99.9% of us. Those guys have more mods and are running quarter miles down into the 10s.

You can try .026". Might work for you. I really can't say.

[01northernS4]

It will always be trial and error when it comes to gap. I guess a few random misfires at idle or low rpm is ok, but you may eventually misfire and stumble. Now that you say those few misfires are at idle or low rpm cruising over 20 minutes, I'd not be concerned.

Personally, I'd go hotter to 8s to completely resolve the issue (I did) but, I'm not claiming to be an expert. As to optimum gap, some guys are even using logging of individual cylinders to set gap by cylinder with slight variations to clean up their logs. That's way beyond 99.9% of us. Those guys have more mods and are running quarter miles down into the 10s.

You can try .026". Might work for you. I really can't say.

yes, originally logged over a 5 min period at operating temp drive but last I checked was over a 20 min drive... at stock I was 0 misfires across the board... I prefer that of course.

I'm leaning towards your approach... but if no major harm leaving single digit misfires I'm seeing now I may just leave it alone as it's a pain to go through that all again...

[01northernS4]

Going to see if Unitronic can qualify why they recommend the iridium 9s as it seems everyone is having better luck with stock platinum 8s.


Now the only question left is between the stock platinum 8s and iridium 8s, does anyone know which would be better on dual pulley or what difference is there, if any?

Any advise or experience appreciated.

Thanks all!
[az][wrench]

[mys4.org]

Rule of thumb more power smaller gap. When timing advances the gap has to be smaller. Seems backwards but it works

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[MSq5]

Going to see if Unitronic can qualify why they recommend the iridium 9s as it seems everyone is having better luck with stock platinum 8s.


Now the only question left is between the stock platinum 8s and iridium 8s, does anyone know which would be better on dual pulley or what difference is there, if any?

Any advise or experience appreciated.

Thanks all!
[az][wrench]

Only practical difference between platinum and fine-wire iridium is that, in theory, iridium should last longer. Its harder and has a higher melting point. This is my first rodeo with iridium on this engine, having run platinum until this set. But, on other boosted engines when running higher than stock boost levels, iridium had lasted longer than platinum. Even so, expect plugs to wear much faster with dual pulley stage 2 boost and cylinder combustion temperatures.

[SILVERBACK004]

Going to see if Unitronic can qualify why they recommend the iridium 9s as it seems everyone is having better luck with stock platinum 8s.


Now the only question left is between the stock platinum 8s and iridium 8s, does anyone know which would be better on dual pulley or what difference is there, if any?

Any advise or experience appreciated.

Thanks all!
[az][wrench]
-----------------------

I switched to Unitronics Dual Pulley, currently running NGK BKR9EIX @ .025 no issues. I'm going to try the NGK BKR8EIX @ .025 because the others one are on back order.

[Silver Streakin]

-----------------------

I switched to Unitronics Dual Pulley, currently running NGK BKR9EIX @ .025 no issues. I'm going to try the NGK BKR8EIX @ .025 because the others one are on back order.

FCP Euro has them. I just got a set this week from them. Search the 2669 PN.

[SILVERBACK004]

FCP Euro has them. I just got a set this week from them. Search the 2669 PN.

------------------------------------

I appreciate it! I will try to purchase a set from them.

[01northernS4]

Yea, it could be because the plugs are new that it felt better WOT. I wouldn't think there is an "adjustment" or break-in period for plugs. It should feel good right away since there is not fowling or carbon built up on them new. As they get older there is the decrease in performance because of the carbon build up.

Strange enough, went logging again last night and misfires across all cylinders were down to about half of what it was before with some cylinders showing zero now... hmmm... I wonder if the coil packs and ecu are adjusting to the new iridium 9 plugs?

I will keep logging the next few days to see if I can get to zero misfires across all cylinders before I try to regap or go back to a hotter iridium 8/platinum stock 8s plug.

Even weirder is that it was 10+ degrees Celsius colder as we just dipped into a cold snap now... would have expected to see more, not less, misfires at idle and low load rpm.

[01northernS4]

I haven't emailed back re still running the 8s and it being fine.

I too originally purchased the new 8s because I was due. Then before installing them, I ended up going DP because of my stock heat exchanger was hit, found radiator was seeping on an end tank, and took advantage of the holiday sale since the crank pulley was right there with the rad out.

I wonder if we should be only using 9 if the 8s are an issue. Maybe in the summer heat?


So what have you decided?

Did you email Unitronic?

Thanks Silver Streakin!

[Silver Streakin]

So what have you decided?

Did you email Unitronic?

Thanks Silver Streakin!

I haven't followed up with Unitronic.

I swapped to my winter wheels on Sunday and took it for a fun drive. I hate not being on summer tires, but it's a complete animal and fine on the 25k miles old stock NGK platinums 8 that I do now recall gapping down a little from .032". I should log it. What block is it? I have a Schwaben scan tool, so it's similar in functions but in different places sometimes. The layout is just a different software.

I was thinking of leaving them in there until spring and try the 9s at their already gapped .028"

I'm work from home so it's rarely getting driven unless I make an excuse to leave the house, which is mostly Home Depot or beer, liquor stores.

[agentsmith988]

I just swapped to some BKR9EIX's gapped to .026 a few days ago. I was running PFR8S8EG's before (35k miles old) and they definitely looked like they were too hot.

I sent a "clear codes" command via VCDS to reset fuel trims for good measure after swapping the plugs. They've been running great.

However, I'm running IE and am just a few cities away from where their tunes were calibrated. They do recommend the BKR9EIX's though.

[01northernS4]

I just swapped to some BKR9EIX's gapped to .026 a few days ago. I was running PFR8S8EG's before (35k miles old) and they definitely looked like they were too hot.

I sent a "clear codes" command via VCDS to reset fuel trims for good measure after swapping the plugs. They've been running great.

However, I'm running IE and am just a few cities away from where their tunes were calibrated. They do recommend the BKR9EIX's though.

hmmm interesting... how did you send that "clear codes" command? I think I need to try that

I've narrowed down the idle and low rpm misfires to basically this... when the car is warm and idling if I quickly jab the throttle I can ramp up the misfires. All other times, generally no misfires (nothing at WOT, high load, high rpm).

Do you get any idle and low misfires or any misfires at all?

Thanks!

[agentsmith988]

hmmm interesting... how did you send that "clear codes" command? I think I need to try that

I've narrowed down the idle and low rpm misfires to basically this... when the car is warm and idling if I quickly jab the throttle I can ramp up the misfires. All other times, generally no misfires (nothing at WOT, high load, high rpm).

Do you get any idle and low misfires or any misfires at all?

Thanks!

Sorry I made made it sound more complicated than it really is! You just clear codes on the engine module (regardless of if there are stored codes or not). This will reset it for you.

[01northernS4]

Sorry I made made it sound more complicated than it really is! You just clear codes on the engine module (regardless of if there are stored codes or not). This will reset it for you.

ahh ok, I cleared all codes across all modules already with vcds... didn't have any misfire codes... the misfires I'm seeing at idle and low rpm load are when I'm logging misfires... didn't know clearing the engine module codes and dtc's via vcds would reset fuel trims...

so do you have any misfires at all after going to the iridium 9s? Does it feel better?

I'm starting to think I should gap down to 0.026" to eliminate the small number of misfires I have at idle/low rpm load as opposed to going back to the hotter plug... you all think that would work?

Thanks again!

[agentsmith988]

ahh ok, I cleared all codes across all modules already with vcds... didn't have any misfire codes... the misfires I'm seeing at idle and low rpm load are when I'm logging misfires... didn't know clearing the engine module codes and dtc's via vcds would reset fuel trims...

so do you have any misfires at all after going to the iridium 9s? Does it feel better?

I'm starting to think I should gap down to 0.026" to eliminate the small number of misfires I have at idle/low rpm load as opposed to going back to the hotter plug... you all think that would work?

Thanks again!

I don't have any misfires and it definitely feels better.

And here's the fuel trim info straight from Ross-Tech (just so you don't think I'm blowing hot air [:D]):


It is totally normal for both the first and second fields to be something other than zero. In fact, zeros IN BOTH FIELDS indicates that either you just cleared codes (which will reset fuel trim values) or something isn't working properly. If values get too far away from zero, it will cause a DTC (fault code) and can set off the MIL (commonly referred to as the Check Engine Light, or CEL). Specifications for normal operation are usually somewhere near +/- 10%.

[6SpeedS4]

Can too cold of a plug cause a rich air/fuel mixture? I had the 9 plugs installed for less than 500 miles before I switched back to 8's. When I pulled the 9's, several of them had some fuel on them. Can this be caused by too cold of plugs ? Should mention it didnt help its been around 20 degrees outside lately.

I also happened to go stage one at the same time so I don't know if it's the tune or the plugs. Let's see if I get any misfires on these new ones.

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[MSq5]

Can too cold of a plug cause a rich air/fuel mixture? I had the 9 plugs installed for less than 500 miles before I switched back to 8's. When I pulled the 9's, several of them had some fuel on them. Can this be caused by too cold of plugs ? Should mention it didnt help its been around 20 degrees outside lately.

I also happened to go stage one at the same time so I don't know if it's the tune or the plugs. Let's see if I get any misfires on these new ones.

Sent from my SM-N975U using Tapatalk

Short answer - no. AFR is set by the ECU and is adjusted within a range depending on operating conditions.

There are many circumstances that can cause an engine to run rich. But, fuel on the plug, unburned fuel, may be an indication the plug is misfiring because it is fouled or because spark is weak (broken or damaged plug tip, failed or failing coil pack) or other reasons. Sounds like you are getting incomplete ignition, which is not the same thing as a rich AFR.

You can log Lambda and see if AFR is out of line. It will be richer under high load, high rpm conditions. That is normal.

[6SpeedS4]

Short answer - no. AFR is set by the ECU and is adjusted within a range depending on operating conditions.

There are many circumstances that can cause an engine to run rich. But, fuel on the plug, unburned fuel, may be an indication the plug is misfiring because it is fouled or because spark is weak (broken or damaged plug tip, failed or failing coil pack) or other reasons. Sounds like you are getting incomplete ignition, which is not the same thing as a rich AFR.

You can log Lambda and see if AFR is out of line. It will be richer under high load, high rpm conditions. That is normal.Thanks. I suspect it was the plug and not the tune. The plugs were fouled after less than 500 miles. https://uploads.tapatalk-cdn.com/20210207/85b3ade848ca8686cec2c281109f6442.jpg

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[RoofRails]

Can too cold of a plug cause a rich air/fuel mixture? I had the 9 plugs installed for less than 500 miles before I switched back to 8's. When I pulled the 9's, several of them had some fuel on them. Can this be caused by too cold of plugs ? Should mention it didnt help its been around 20 degrees outside lately.

I also happened to go stage one at the same time so I don't know if it's the tune or the plugs. Let's see if I get any misfires on these new ones.

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It's not a rich mixture fouling the plugs. Its the #9 heat range plug not getting hot enough to burn off the deposits. Drop back to a #8 heat range plug and everything should be good to go.

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[djn876]

Yup this^. I liked the brisk plugs, but they fouled super fast in the winter as I think they just didn't stay hot enough. You might look at swapping seasonally and see how it works out since it takes maybe 30 min to change plugs.

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[6SpeedS4]

Got it. Thanks everyone.

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[MSq5]

Got it. Thanks everyone.

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Honestly, run 8s and roll.

[01northernS4]

Wow so I just dropped back down to heat range 8 ngk bkr8eix from the 9s I installed last week... still single digit misfires at idle and low rpm load blipping the throttle... don't ever recall this happening on the stock original platinum ngk 8 heat range plugd... now I'm at a loss... does my car not like the iridiums? Anyone else experience this?

Only other difference was stock plug was .032" and this bkr8eix is .028".

Help. Any suggestions appreciated.

[wangshuo1989]

Wow so I just dropped back down to heat range 8 ngk bkr8eix from the 9s I installed last week... still single digit misfires at idle and low rpm load blipping the throttle... don't ever recall this happening on the stock original platinum ngk 8 heat range plugd... now I'm at a loss... does my car not like the iridiums? Anyone else experience this?

Only other difference was stock plug was .032" and this bkr8eix is .028".

Help. Any suggestions appreciated.

My local APR shop told me when they replace spark plugs they still use OEM plugs and just gap down a bit, even for dual pulley cars.
I am currently APR dually pulley and I am still on stock plugs with stock gap, no misfire ever and pulls pretty hard. I used vcds mobile to log it and it shows 0 misfire for multiple third gear pull.

[djn876]

Are you actually pulling timing or can feel a misfire? Is the car disabling a cylinder? If not I would stop worrying about that misfire count, I don't think I've ever logged that, and my tuner has never requested it of the 60 or so parameters we usually log.

I would ask what a normal or acceptable value is? Could be what you are seeing is fine as long as it is not impacting performance.

Otherwise if you feel like something is going on, it's could very well be unrelated to the plugs. You need to see how the car is doing overall with fueling, boost, etc. to get an accurate picture as a whole. Right now you are focusing on one piece of the puzzle but a lot of other things could be a contributor.

The car is pretty sensitive to it, >1.5% for 1000 RPM for two drive cycles is what will trigger a code, unless it is excessive, then it will trigger a MIL immediately.

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[01northernS4]

My local APR shop told me when they replace spark plugs they still use OEM plugs and just gap down a bit, even for dual pulley cars.
I am currently APR dually pulley and I am still on stock plugs with stock gap, no misfire ever and pulls pretty hard. I used vcds mobile to log it and it shows 0 misfire for multiple third gear pull.

Good to know... I also have no misfires on high rpm and load pulls but only when monitoring misfires at idle and low load rpm... the bkr9eix also had a white coating on the strap and deep black carbon on the threads... looks too cold and thought that was was causing my low rpm misfire... again I'm thinking it's the iridium since nothing else has changed except the gap lower to .028 from .032...

Anyone else think the iridium are the problem or had problems with them?

[01northernS4]

Are you actually pulling timing or can feel a misfire? Is the car disabling a cylinder? If not I would stop worrying about that misfire count, I don't think I've ever logged that, and my tuner has never requested it of the 60 or so parameters we usually log.

I would ask what a normal or acceptable value is? Could be what you are seeing is fine as long as it is not impacting performance.

Otherwise if you feel like something is going on, it's could very well be unrelated to the plugs. You need to see how the car is doing overall with fueling, boost, etc. to get an accurate picture as a whole. Right now you are focusing on one piece of the puzzle but a lot of other things could be a contributor.

The car is pretty sensitive to it, >1.5% for 1000 RPM for two drive cycles is what will trigger a code, unless it is excessive, then it will trigger a MIL immediately.

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Good points... I guess the problem is the change to iridium from platinum and the lowering of the Gap from .32 to .28 are the only things that have changed and now I'm seeing these low RPM and load misfires which is annoying... never had thus before. Haven't been able to fully log due to weather but the idle feels ok not perfectly butter smooth as usual otherwise no misfires at high RPM.

Still thinking the iridium may be the problem as it's the only think that has changed... 10 or 20 min drive low level of misfires like 5 to 8 each across all cylinders easily repeatable if I jab the throttle quickly while idling I can watch the misfire count go up. Good news is no cylinder disable or codes as I believe the number is too low for that and does seem to perform flawlessly at high RPM and load.

It does seem the bkr9eix I had in there were fouled considering I only ran a week... had hoped the bkr8eix would have resolved these low level misfires...

Can iridium be a problem? Should I go back to oem platinum or leave it alone?

[MSq5]

Good to know... I also have no misfires on high rpm and load pulls but only when monitoring misfires at idle and low load rpm... the bkr9eix also had a white coating on the strap and deep black carbon on the threads... looks too cold and thought that was was causing my low rpm misfire... again I'm thinking it's the iridium since nothing else has changed except the gap lower to .028 from .032...

Anyone else think the iridium are the problem or had problems with them?

I agree with others. Stop obsessing about slight misfires at idle or cruise. Maybe run a full VCDS scan for other soft codes. For instance, a failing PCV (common on our cars) can produce misfires at idle or low load and clear up completely under load. Not saying that is the issue. If you have no soft codes, just stop worrying and enjoy the iridium plugs.

[01northernS4]

I agree with others. Stop obsessing about slight misfires at idle or cruise. Maybe run a full VCDS scan for other soft codes. For instance, a failing PCV (common on our cars) can produce misfires at idle or low load and clear up completely under load. Not saying that is the issue. If you have no soft codes, just stop worrying and enjoy the iridium plugs.

To be honest this is what I'm leaning towards...

I guess at this point I'll stick with the 8 heat range iridium as they already in and are less likely to foul and keep the 9s for summer if needed and log dependent... had I known all this I probably would have gone oem platinum range 8 as it was pristine 0 misfires and avoided all this back and forth. oh well.

small consolation, hopefully my logs up high look better with the iridium... not that they were bad with the oem platinum 8s though... hopefully this helps someone else deciding on plugs... seems heat range 8 at dual pulley .024 to .028 platinums are best?...

Thanks all!

[djn876]

I run the iridiums (8s) because they were more easily accessible locally for me than the stock plugs and I have no issues with them. The stock plugs should be fine as well though, just smaller gap for the DP. I fouled brisk plugs pretty quick and was getting actual misfires (you could feel them) and cylinder disabling just from normal driving. Other than that plugs haven't made that much of a difference, times I thought they were a problem was almost always something else (HPFP, intercooler, etc.). If it matters, I run .025-.026 gap (194/57, W/M, E40). Really you'd probably be fine with anything between 0.024 - 0.028.

[wangshuo1989]

Good to know... I also have no misfires on high rpm and load pulls but only when monitoring misfires at idle and low load rpm... the bkr9eix also had a white coating on the strap and deep black carbon on the threads... looks too cold and thought that was was causing my low rpm misfire... again I'm thinking it's the iridium since nothing else has changed except the gap lower to .028 from .032...

Anyone else think the iridium are the problem or had problems with them?

I can log my car’s idle misfire and let you know. Today is pretty busy and I am aiming to refuel it and do it tonight.

[01northernS4]

I run the iridiums (8s) because they were more easily accessible locally for me than the stock plugs and I have no issues with them. The stock plugs should be fine as well though, just smaller gap for the DP. I fouled brisk plugs pretty quick and was getting actual misfires (you could feel them) and cylinder disabling just from normal driving. Other than that plugs haven't made that much of a difference, times I thought they were a problem was almost always something else (HPFP, intercooler, etc.). If it matters, I run .025-.026 gap (194/57, W/M, E40). Really you'd probably be fine with anything between 0.024 - 0.028.

hmm interesting... I am on the high end of the gap at .028 ish+ to .029/.030? could dropping the gap to below .028" possibly help with the small number of idle misfires? I logically thought only the heat range would account for the misfires only at idle and low load...

again, leaning to leaving everything as is since wot logs look good no misfires and no codes/weird behavior/can't feel misfires

[01northernS4]

I can log my car’s idle misfire and let you know. Today is pretty busy and I am aiming to refuel it and do it tonight.

that's awesome thanks wangshuo1989 that'd be great!

when you do if it reads 0's across all cylinders give the throttle a quick jab/blib... when I do this I can ramp up my misfires pretty quickly... wonder why that's so.

another interesting point this behavior only happens when engine is warm at operating temp... on cold start/cold engine no misfires at idle or any rpm... only misfires at idle/low load rpm when warm.

cheers

[mark920]

that's awesome thanks wangshuo1989 that'd be great!

when you do if it reads 0's across all cylinders give the throttle a quick jab/blib... when I do this I can ramp up my misfires pretty quickly... wonder why that's so.

another interesting point this behavior only happens when engine is warm at operating temp... on cold start/cold engine no misfires at idle or any rpm... only misfires at idle/low load rpm when warm.

cheersI have this same issue with denso iridium ik24's, I just out them in, and I previously had ik24's. I think my pcv is going bad b/c I get a soft pcv code in vcds and after clearing it randomly comes back. https://uploads.tapatalk-cdn.com/20210209/b296c925ffa5c5ce589a881ea141bc9c.jpg

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[djn876]

I have this same issue with denso iridium ik24's, I just out them in, and I previously had ik24's. I think my pcv is going bad b/c I get a soft pcv code in vcds and after clearing it randomly comes back. https://uploads.tapatalk-cdn.com/20210209/b296c925ffa5c5ce589a881ea141bc9c.jpg

Sent from my SM-N986U using TapatalkThat plug looks like it is coolant fouled, I'd check your intercoolers. Though I guess could be coolant from the PCV too.

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[mark920]

That plug looks like it is coolant fouled, is check your intercoolers.

Sent from my SM-G988U using Audizine Forum mobile app (http://r.tapatalk.com/byo?rid=87676)I am not sure I understand, can you elaborate? This is the pcv code I get. Also, the newest set of the IK24's I gapped to .024 and I do not get misfires under load, I have a pulley ratio of 3.0 (192mm CTS crank pulley, stock upper, IE stage 2+ tune, merc v3 hx).https://uploads.tapatalk-cdn.com/20210209/111ae39e895a6daa89d620824f605dba.jpg

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[djn876]

I am not sure I understand, can you elaborate? This is the pcv code I get. Also, the newest set of the IK24's I gapped to .024 and I do not get misfires under load, I have a pulley ratio of 3.0 (192mm CTS crank pulley, stock upper, IE stage 2+ tune, merc v3 hx).https://uploads.tapatalk-cdn.com/20210209/111ae39e895a6daa89d620824f605dba.jpg

Sent from my SM-N986U using TapatalkThe new plugs haven't had time to foul yet is my guess that plug definitely doesn't look normal. I've seen octane booster make them look like that too if you are using any.

That code just means the PCV is not maintaining pressure within the normal range.

When the PCV fails it often results in coolant mixing in due to cracking. It could get entrained into the air intake and eventually make its way to the cylinder. This then causes the fouling you see.

Otherwise leaking intercoolers from the charger can cause that too as they drip into the cylinder.

Did all of the plugs look like that or just one or two?

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[mark920]

The new plugs haven't had time to foul yet is my guess that plug definitely doesn't look normal. I've seen octane booster make them look like that too if you are using any.

That code just means the PCV is not maintaining pressure within the normal range.

When the PCV fails it often results in coolant mixing in due to cracking. It could get entrained into the air intake and eventually make its way to the cylinder. This then causes the fouling you see.

Otherwise leaking intercoolers from the charger can cause that too as they drip into the cylinder.

Did all of the plugs look like that or just one or two?

Sent from my SM-G988U using Audizine Forum mobile app (http://r.tapatalk.com/byo?rid=87676)No they all looked pretty similar though I had run an octane booster in the last month prior to changing them... However, pcv needs to be changed from my understanding of the code so I don't really know which caused the fouling.

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[djn876]

No they all looked pretty similar though I had run an octane booster in the last month prior to changing them... However, pcv needs to be changed from my understanding of the code so I don't really know which caused the fouling.

Sent from my SM-N986U using TapatalkIn that case it's probably the octane booster, I'd say try and avoid that if you can. The PCV should get done, but I don't think that was your issue, all of the plugs looking like that would likely be the booster.

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[wangshuo1989]

that's awesome thanks wangshuo1989 that'd be great!

when you do if it reads 0's across all cylinders give the throttle a quick jab/blib... when I do this I can ramp up my misfires pretty quickly... wonder why that's so.

another interesting point this behavior only happens when engine is warm at operating temp... on cold start/cold engine no misfires at idle or any rpm... only misfires at idle/low load rpm when warm.

cheers

I just fueled my car at a shell station near a whole food market after getting grocery. I started the live data and drove home. It’s about 8 mile, 50/50 local and highway. Pulled once on highway and idle in garage for 20 seconds to blip the throttle, misfire count stayed dead 0 all the time. The car is warm and oil temperature shows 202F.
https://uploads.tapatalk-cdn.com/20210210/205a2252ba2cc48e09d0e7a86a2e2145.jpg


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[ModItNow]

Wow so I just dropped back down to heat range 8 ngk bkr8eix from the 9s I installed last week... still single digit misfires at idle and low rpm load blipping the throttle... don't ever recall this happening on the stock original platinum ngk 8 heat range plugd... now I'm at a loss... does my car not like the iridiums? Anyone else experience this?

Only other difference was stock plug was .032" and this bkr8eix is .028".

Help. Any suggestions appreciated.

I've experienced with different plugs over the years, NGK Iridium 8/9's and Brisk. The oem plugs have been the most reliable, I have them gapped to .025" (I'm DP). Don't need to switch them out as often either. I think the only time you need to change is if your summer is super hot and then I would run Brisk 12ys.

[01northernS4]

I've experienced with different plugs over the years, NGK Iridium 8/9's and Brisk. The oem plugs have been the most reliable, I have them gapped to .025" (I'm DP). Don't need to switch them out as often either. I think the only time you need to change is if your summer is super hot and then I would run Brisk 12ys.

so the oem platinum>ngk iridium/brisk/etc... for you... did you experience misfires as well or any other strange behavior?

I wonder why all the tuners seem to prefer the iridiums?

[01northernS4]

I just fueled my car at a shell station near a whole food market after getting grocery. I started the live data and drove home. It’s about 8 mile, 50/50 local and highway. Pulled once on highway and idle in garage for 20 seconds to blip the throttle, misfire count stayed dead 0 all the time. The car is warm and oil temperature shows 202F.
https://uploads.tapatalk-cdn.com/20210210/205a2252ba2cc48e09d0e7a86a2e2145.jpg


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thanks for this, much appreciated

I just don't understand why the tuners and many seem to prefer the iridium... I may go back to oem as even the small number of misfires at idle can't be great... after I do a full pull log I'll see if there are any benefits from these iridiums and go from there... it seems stronger up top and mid range but that may be due to the fact the iridiums are new vs the stock original platinums...

I wonder if it has to do with the larger electrode firing head on the platinum vs smaller on the iridium?

[6SpeedS4]

so the oem platinum>ngk iridium/brisk/etc... for you... did you experience misfires as well or any other strange behavior?

I wonder why all the tuners seem to prefer the iridiums?Fwiw, I went from heat range 9 iridium to oem with stock gap and then oem with 0.028 gap and still get misfires at idle. Single digits over an hour of driving which was mainly highway. I may pull them one more time and go 0.30 since I'm only stage 1. If that doesn't help then I'm out of ideas.

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[ModItNow]

so the oem platinum>ngk iridium/brisk/etc... for you... did you experience misfires as well or any other strange behavior?

I wonder why all the tuners seem to prefer the iridiums?I only had weird misfiring with the 9's. If you don't mind changing your plugs every oil change then the brisk 12YS are the best, only lasted 7k miles for me. I decided to stay with oem for the longevity. I think the iridium 8's work pretty good too.

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[MSq5]

thanks for this, much appreciated

I just don't understand why the tuners and many seem to prefer the iridium... I may go back to oem as even the small number of misfires at idle can't be great... after I do a full pull log I'll see if there are any benefits from these iridiums and go from there... it seems stronger up top and mid range but that may be due to the fact the iridiums are new vs the stock original platinums...

I wonder if it has to do with the larger electrode firing head on the platinum vs smaller on the iridium?

Iridium handles combustion chamber heat better than platinum. It has a higher melting point and is harder. It is also easier to manufacture a fine wire tip which is supposedly a better design for use with high pressure direct injection.

[6SpeedS4]

Fwiw, I went from heat range 9 iridium to oem with stock gap and then oem with 0.028 gap and still get misfires at idle. Single digits over an hour of driving which was mainly highway. I may pull them one more time and go 0.30 since I'm only stage 1. If that doesn't help then I'm out of ideas.

Sent from my SM-N975U using TapatalkIs it possible that a heat range 8 plug can run too cold (during idle) if the weather is cold enough ? I'm curious if the combination of 20° F weather and the merc hx is overkill for stage 1. Will be interesting to monitor during warmer weather.

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[MSq5]

Why are you guys obsessing about low count misfires at idle? No CELs, no soft codes, no drivability issues. Cars running like raped apes otherwise. Maybe just COVID and too much time on your hands?

[Izzyz28]

Why are you guys obsessing about low count misfires at idle? No CELs, no soft codes, no drivability issues. Cars running like raped apes otherwise. Maybe just COVID and too much time on your hands?

Seriously, this is the most OCD-like thing I have seen in a long time, just leave it be. And how on Earth are people getting less than 10K out of a set of plugs? The only time your mods affect anything with the plugs is under WOT, otherwise it will idle and run exactly the same as a stock car.

[6SpeedS4]

Why are you guys obsessing about low count misfires at idle? No CELs, no soft codes, no drivability issues. Cars running like raped apes otherwise. Maybe just COVID and too much time on your hands?LOL.

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[djn876]

Why are you guys obsessing about low count misfires at idle? No CELs, no soft codes, no drivability issues. Cars running like raped apes otherwise. Maybe just COVID and too much time on your hands?

I can't like this enough.

[MSq5]

Out of curiosity, I logged my engine this afternoon at idle for about 20 minutes while in my shop working on something else. Mods are dual pulley stage 2 and as set forth in signature below. Plugs are NGK BRK8EIX Iridium gapped to .028" with about 7,000 miles on them. Car has 69,600 miles on it.

No load, obviously. Idle with occasional throttle blip and a couple minutes at 2,000 rpm as I passed by the car to pick up a tool or part (replacing a starter on a tractor).

Cut to the chase: Logs show zero misfires per 1000 rpm across all cylinders for the entire log.

Conclusion. Whatever may be causing some users idle and low load misfires is not due to heat range 8 Iridium NGK plugs.

Nor would it bother me if I did see a few single digit instances on the logs. Much ado over nothing, IMO.

[6SpeedS4]

Out of curiosity, I logged my engine this afternoon at idle for about 20 minutes while in my shop working on something else. Mods are dual pulley stage 2 and as set forth in signature below. Plugs are NGK BRK8EIX Iridium gapped to .028" with about 7,000 miles on them. Car has 69,600 miles on it.

No load, obviously. Idle with occasional throttle blip and a couple minutes at 2,000 rpm as I passed by the car to pick up a tool or part (replacing a starter on a tractor).

Cut to the chase: Logs show zero misfires per 1000 rpm across all cylinders for the entire log.

Conclusion. Whatever may be causing some users idle and low load misfires is not due to heat range 8 Iridium NGK plugs.

Nor would it bother me if I did see a few single digit instances on the logs. Much ado over nothing, IMO.Reason I'm slightly concerned is I'm not idling for nearly that long. I'm afraid I'd be well over 20-30 misfires/cyclinder if I idled for 20 minutes. Only other thing I can think of is I replaced the ignition coils with Denso instead of OEM but they certainly weren't cheap.

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[01northernS4]

Reason I'm slightly concerned is I'm not idling for nearly that long. I'm afraid I'd be well over 20-30 misfires/cyclinder if I idled for 20 minutes. Only other thing I can think of is I replaced the ignition coils with Denso instead of OEM but they certainly weren't cheap.

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+1 but only difference for me is I will stay in single digit misfires at idle/low load unless I blip the throttle quickly ... in which case I can get up to double digit misfires very quickly


Out of curiosity, I logged my engine this afternoon at idle for about 20 minutes while in my shop working on something else. Mods are dual pulley stage 2 and as set forth in signature below. Plugs are NGK BRK8EIX Iridium gapped to .028" with about 7,000 miles on them. Car has 69,600 miles on it.

No load, obviously. Idle with occasional throttle blip and a couple minutes at 2,000 rpm as I passed by the car to pick up a tool or part (replacing a starter on a tractor).

Cut to the chase: Logs show zero misfires per 1000 rpm across all cylinders for the entire log.

Conclusion. Whatever may be causing some users idle and low load misfires is not due to heat range 8 Iridium NGK plugs.

Nor would it bother me if I did see a few single digit instances on the logs. Much ado over nothing, IMO.

Thanks for doing this logging MSq5 and trying to help out...

Unfortunately in my case the ONLY thing that changed for me was going to iridium 9 then iridium 8 from original stock ngk platinum... and I only went from 9 to 8 to try and eliminate the idle/low load misfires that were not there on oem platinums so hard to say definitively "Whatever may be causing some users idle and low load misfires is not due to heat range 8 Iridium NGK plugs." - as I could say the opposite is true in my controlled experiment...

I agree it's probably not a big deal but it is a head scratcher as to why it's only happening on the iridium plugs for me, regardless of heat range soo far... also went through a few different tanks of gas just in case I had a bad fill up but always the same station and 94 octane so...

my next step is to gap down further then rotate back to the stock oem platinums again to triple check no misfires... the kicker is the oem platinums were gaped at .032 and the iridium is at tuner recommended .028... may try .026 for shits and giggles.

Anyone else have problems with iridiums?

By any chance, can the smaller iridium tip exasperate existing misfire tendencies compared to the larger platinum tip?

[MSq5]

+1 but only difference for me is I will stay in single digit misfires at idle/low load unless I blip the throttle quickly ... in which case I can get up to double digit misfires very quickly



Thanks for doing this logging MSq5 and trying to help out...

Unfortunately in my case the ONLY thing that changed for me was going to iridium 9 then iridium 8 from original stock ngk platinum... and I only went from 9 to 8 to try and eliminate the idle/low load misfires that were not there on oem platinums so hard to say definitively "Whatever may be causing some users idle and low load misfires is not due to heat range 8 Iridium NGK plugs." - as I could say the opposite is true in my controlled experiment...

I agree it's probably not a big deal but it is a head scratcher as to why it's only happening on the iridium plugs for me, regardless of heat range soo far... also went through a few different tanks of gas just in case I had a bad fill up but always the same station and 94 octane so...

my next step is to gap down further then rotate back to the stock oem platinums again to triple check no misfires... the kicker is the oem platinums were gaped at .032 and the iridium is at tuner recommended .028... may try .026 for shits and giggles.

Anyone else have problems with iridiums?

By any chance, can the smaller iridium tip exasperate existing misfire tendencies compared to the larger platinum tip?

Just no.

The finer tip is a benefit.

Tighter gapping is contraindicated. We gap tighter with higher than stock maximum full throttle boost (a condition not present at idle or cruising) to reduce "spark boost blow out."

This is a condition akin to trying to light a candle in a windstorm. You have to get your match closer to the wick or the wind will blow it out. High boost well above stock can actually blow out the spark if the gap is too large, so we tighten up the gap. When this condition happens, the engine stumbles under high boost high load and then recovers when you lift throttle a little.

Here is a good read on the general subject:

https://www.enginelabs.com/engine-tech/ignition-electronics-efi/the-great-spark-plug-debate-separating-fact-from-opinion/

[01northernS4]

Just no.

The finer tip is a benefit.

Tighter gapping is contraindicated. We gap tighter with higher than stock maximum full throttle boost (a condition not present at idle or cruising) to reduce "spark boost blow out."

This is a condition akin to trying to light a candle in a windstorm. You have to get your match closer to the wick or the wind will blow it out. High boost well above stock can actually blow out the spark if the gap is too large, so we tighten up the gap. When this condition happens, the engine stumbles under high boost high load and then recovers when you lift throttle a little.

Here is a good read on the general subject:

https://www.enginelabs.com/engine-tech/ignition-electronics-efi/the-great-spark-plug-debate-separating-fact-from-opinion/

Great read and info in the link you provided... Thanks!

Did glean this under the "testing plugs" section -- "So the combination of increasing the heat range, and the platinum center electrode contributed to making the engine idle better, cleaner, and more efficiently."

Maybe there is something to the platinum tip > iridium tip only at idle?

Thoughts?

[MSq5]

Great read and info in the link you provided... Thanks!

Did glean this under the "testing plugs" section -- "So the combination of increasing the heat range, and the platinum center electrode contributed to making the engine idle better, cleaner, and more efficiently."

Maybe there is something to the platinum tip > iridium tip only at idle?

Thoughts?

Yes, you're misreading it, or certainly reading into it something not there. Nowhere in that example does it state what kind of tip or material the old plugs had, only that they were two steps colder heat range and were the ones used for dyno testing.

The inference, however, is that they were either copper or nickel. Note the chart immediately below the example showing the increasing melting point from copper to nickel to platinum to iridium. One simply cannot infer iridium as the tip for the old plugs.

Throughout the article the author advocates fine wire iridium plugs for high boost forced induction engines like ours. Take note that the example engine was a normally aspirated EFI engine - no forced induction, no direct injection.

Forgive me for saying this but you will spend more time, energy and money chasing a solution to a "problem" unrelated to the composition of the your spark plug tips.

[Izzyz28]

Understanding how the ECU detects things like misfires and knock may help a person understand why idling and revving the shit out of an engine with no load can lead to false readings. It's not like there is a "misfire sensor", other data is used to infer there may have been a misfire(crank angle, acceleration and such). BTW, I run knock-off Chinese coils from Amazon and stock plugs with 40K on them, DP with W/M on a 104 file and have exactly 0 issues.

[djn876]

The engine has two knock sensors, one for each bank, and reads the voltage produced to determine if a knock event has occurred. As there are only two, it must utilize crank angle, or some other sensor to determine which cylinder actually produced the knock event. The system from my experience is fairly sensitive to knock events and will start adjusting timing.

Again, the misfire counts almost don't matter, watch timing. You can do this on an individual cylinder basis if you want, that will tell you if the cylinder is experiencing a knock event that the ECU is taking action on. It just seems like a lot of data is being discussed here that has such a small sample size, no one knows what's normal and is just being assumed that 0 is what it should be all the time, which is not true or the ECU threshold would be much lower. In addition, the tuner could change the knock threshold as well which would lower the number of detected events.

It simply makes more sense to monitor the vehicle performance under load and determine if it is having any issues and monitoring numerous parameters more globally rather than focusing on one item and then try and understand why it does what it does without understanding the multitude of inputs that will impact that parameter.

We say the plugs or gap is the only thing that changed, but maybe the car was refueled, maybe it was raining vs. not, maybe it was colder or warmer that day, etc. etc.

Run some good logs with the car on a 3rd gear pull at least, or better yet a full 1/4 mile to get an accurate picture of the cars performance. There are a lot of good threads out there for what to log if you don't have a standard set-up already.

[6SpeedS4]

The engine has two knock sensors, one for each bank, and reads the voltage produced to determine if a knock event has occurred. As there are only two, it must utilize crank angle, or some other sensor to determine which cylinder actually produced the knock event. The system from my experience is fairly sensitive to knock events and will start adjusting timing.

Again, the misfire counts almost don't matter, watch timing. You can do this on an individual cylinder basis if you want, that will tell you if the cylinder is experiencing a knock event that the ECU is taking action on. It just seems like a lot of data is being discussed here that has such a small sample size, no one knows what's normal and is just being assumed that 0 is what it should be all the time, which is not true or the ECU threshold would be much lower. In addition, the tuner could change the knock threshold as well which would lower the number of detected events.

It simply makes more sense to monitor the vehicle performance under load and determine if it is having any issues and monitoring numerous parameters more globally rather than focusing on one item and then try and understand why it does what it does without understanding the multitude of inputs that will impact that parameter.

We say the plugs or gap is the only thing that changed, but maybe the car was refueled, maybe it was raining vs. not, maybe it was colder or warmer that day, etc. etc.

Run some good logs with the car on a 3rd gear pull at least, or better yet a full 1/4 mile to get an accurate picture of the cars performance. There are a lot of good threads out there for what to log if you don't have a standard set-up already.Thanks for the feedback. I actually have a ross-tech arriving today as I have been using torque pro.

This could easily be chalked up to a bad batch of winter gas but look forward to learning how to log.

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[djn876]

It's not bad gas. It's really nothing at all, unless it results in a performance issue it's really not even worth monitoring.

Believe me I've been there, I spent a long time chasing random knock under load with different plugs, gaps, etc. for a few weeks and messed with it for a while. In the end nothing really made much of a difference and in the end I spent a bunch of time looking at my logs and comparing to others and it seemed on par with what was normal/average for this motor and stage of tune.

I love data and monitoring stuff, but important to focus on key stuff, IAT, making sure car is getting the fuel it's calling for, timing, etc.

Once I moves past trying to get everything to read 100% perfect all of the time, I was able to just get out and actually enjoy the car!

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