[F87source]

Originally Posted by Leaveatrail86

.30?!

Wow. That’s a big difference.

0.030".

Yeah the gap is supposed to be that big, which is what shocks me when there are users running 0.018". Like that can't be running smoothly.

[Leaveatrail86]

Originally Posted by F87source

0.030".

Yeah the gap is supposed to be that big, which is what shocks me when there are users running 0.018". Like that can't be running smoothly.

I’m just baffled as to why protuning advises/recommends .22-.23

Seems like a lotta m2 owners are having misfires with that gap. I just know that I’m going to try .26 and go from there. Also wondering if I may have gotten a bad batch of 97506’s. What’s sketch is that my friend with an f80 had that happen to him. He had one bad 97506 that was supposedly brand new. He happened to have an extra one laying around and it solved his issue.

Seems like a quality control thing with NGK if anything. Wow..

[F87source]

Originally Posted by Leaveatrail86

I’m just baffled as to why protuning advises/recommends .22-.23

Seems like a lotta m2 owners are having misfires with that gap. I just know that I’m going to try .26 and go from there. Also wondering if I may have gotten a bad batch of 97506’s. What’s sketch is that my friend with an f80 had that happen to him. He had one bad 97506 that was supposedly brand new. He happened to have an extra one laying around and it solved his issue.

Seems like a quality control thing with NGK if anything. Wow..

Imo it's better to start big (especially since you have a coil upgrade, like I said you gap down only if you have no other choice otherwise you're essentially wasting your coil upgrade) and gap down if needed, because if you start small you may see there's no issue but you're leaving extra gap space on the table.

[Leaveatrail86]

Originally Posted by F87source

Imo it's better to start big (especially since you have a coil upgrade, like I said you gap down only if you have no other choice otherwise you're essentially wasting your coil upgrade) and gap down if needed, because if you start small you may see there's no issue but you're leaving extra gap space on the table.

Thank you. Appreciate your time.

As soon as I get home, I’ll regap to .26 and log. I’ll post the log here. If you don’t mind, can you can lend me a hand and see if you see anything off? I’m still learning to read the logs myself. Thank you again

[F87source]

Originally Posted by Leaveatrail86

Thank you. Appreciate your time.

As soon as I get home, I’ll regap to .26 and log. I’ll post the log here. If you don’t mind, can you can lend me a hand and see if you see anything off? I’m still learning to read the logs myself. Thank you again

No problem, but again I'd gap to 0.030, or at the very least 0.028" then go down. ZM2 is pushing his car quite hard on e40 and an upgraded stage 1 turbo - to the tune of 470ish whp, and that's running fine on a 0.026" gap. So your car should be more than capable of sustain the spark with that especially with upgraded coils and less significant mods, so why target smaller? If I were you I'd go 0.030", and only gap down if needed.

[Leaveatrail86]

Originally Posted by F87source

No problem, but again I'd gap to 0.030, or at the very least 0.028" then go down. ZM2 is pushing his car quite hard on e40 and an upgraded stage 1 turbo - to the tune of 470ish whp, and that's running fine on a 0.026" gap. So your car should be more than capable of sustain the spark with that especially with upgraded coils and less significant mods, so why target smaller? If I were you I'd go 0.030", and only gap down if needed.

I went ahead and increased the gap to .26 just because I had a lot of hope with the results zm2 had. Of course, with your guidance and knowledge. Definitely runs smoother and stronger! Very smooth idle now. However, that lope/misfire only happens when I put it in 1st gear or in reverse. Really weird. It’s not a horrible misfire, but it’s there.

What I did do was disconnect the pre cat o2 sensor to see if it would change anything. There was a slight minuscule change but not much. Could it be the pre cat o2 sensor? How can I test it

[F87source]

Originally Posted by Leaveatrail86

I went ahead and increased the gap to .26 just because I had a lot of hope with the results zm2 had. Of course, with your guidance and knowledge. Definitely runs smoother and stronger! Very smooth idle now. However, that lope/misfire only happens when I put it in 1st gear or in reverse. Really weird. It’s not a horrible misfire, but it’s there.

What I did do was disconnect the pre cat o2 sensor to see if it would change anything. There was a slight minuscule change but not much. Could it be the pre cat o2 sensor? How can I test it

1) Just because one user has success with a plug gap range doesn't mean you should follow it because every car and use case is different (maybe one car had weaker coils), and especially because you also have much more powerful coils meaning you have alot more potential to chose larger gap sizes. This is why you always go to the max gap (stock) and go down only when needed, so you can get the largest gap size possible - remember gapping down is not a desirable thing it means you don't have the coil energy to maintain the spark. So when you follow another user's gap size choice without any prior testing on your own setup - especially when you are following a gap size utilizing stock coils on a much more agressive setup (meaning the requirements for a smaller gap may be valid) you are literally throwing away all the gains you have by upgrading coils because you don't need to gap down. Sure 0.026" doesn't seem to pose any issues with misfiring or idle, but again why would you gap down when it's not needed - this is even more emphasized because you have upgraded coils and gapping down when you don't need to is like throwing money for coil upgrades in the garbage. (Sorry if I sound harsh, I'm just trying to explain this as best I can, not trying to be a douche).

But at the end of the day it's your choice, I just think it's a bad idea to gap down when not needed.


2) Did you put anti-sieze on your spark plugs?

3) Wait wait wait, you did what? NEVER unplug the pre cat o2 sensor, that is what the car uses to detect afr's, removing this cripples the cars ability to accurately detect these values and can put it in limp mode or even worse blow the motor.


If the cat is fouled afr's values would be very off, and you may get codes.

[eeyang92]

I have to second what F87source is saying here - I have B58 coils and NGKs, I increased the gap from 0.023" to 0.028" and the car feels great even on E45-E50 mix. I do have stock plugs coming in that should be at stock gap (0.030"-0.032") which I will try next.

[F87source]

Don't forget, no anti seize on spark plugs. The plugs are already coated from the factory and do not require antisieze.


Not only can anti seize end up on the plug tips causing misfires and fouling of the plugs, but it is also a torque multiplier and can cause stripping.

[Leaveatrail86]

Originally Posted by eeyang92

I have to second what F87source is saying here - I have B58 coils and NGKs, I increased the gap from 0.023" to 0.028" and the car feels great even on E45-E50 mix. I do have stock plugs coming in that should be at stock gap (0.030"-0.032") which I will try next.

Thanks for that. I am on an e45 mix myself at the moment. I’ve been working a lot, so I haven’t tried the .28 gap yet. Still on .26.

What I’m experiencing is a choppy exhaust note at load, as I get into 1st gear I can hear it break up. Of course, that lessened substantially at the .26 gap.

I did see a YouTube video of Zero to 60 showing you how to test your spark plugs with a multimeter. I’m going to test them out before putting them back in. I mean, they literally have under 100 miles on the 97506’s. Perhaps, one or two are defective.

[eeyang92]

Originally Posted by Leaveatrail86

Thanks for that. I am on an e45 mix myself at the moment. I’ve been working a lot, so I haven’t tried the .28 gap yet. Still on .26.

What I’m experiencing is a choppy exhaust note at load, as I get into 1st gear I can hear it break up. Of course, that lessened substantially at the .26 gap.

I did see a YouTube video of Zero to 60 showing you how to test your spark plugs with a multimeter. I’m going to test them out before putting them back in. I mean, they literally have under 100 miles on the 97506’s. Perhaps, one or two are defective.

If you have misfires, definitely try a smaller and smaller gap - just be aware your idle may become rougher and your mileage will go down (due to incomplete combustion). At a certain point (maybe below 0.022") it might just be more beneficial to upgrade the coils and go back to stock gap.

[Leaveatrail86]

Originally Posted by eeyang92

If you have misfires, definitely try a smaller and smaller gap - just be aware your idle may become rougher and your mileage will go down (due to incomplete combustion). At a certain point (maybe below 0.022") it might just be more beneficial to upgrade the coils and go back to stock gap.

Currently have the Precision Raceworks Ignition Coils. You’re definitely right about the rough idle. I remember what it felt like @.24

Stock gap is .28 from what I understand. Gonna test them to make sure the plugs are good, and then gap to .28. Hopefully good results. Sometimes I feel like trowing the oem plugs back in to see if that yields positive results. I still have them.

[Leaveatrail86]

So I went ahead and test the new spark plugs I bought from Precision Raceworks. Three are weak, 2 are bad and only 1 is good.

4.45, 4.28, 4.26, 4.61, 4.49, 4.47ohm’s. These plugs have less than 100 miles. Go figure. Quality control, fakes or junk?

The old plugs were 97506 as well but purchased from Burger Tuning.

5.11, 5.03, 4.47, 4.84, 4.62, 4.18. Old plugs. I was better off with the old plugs. The 4.18 I’m guessing was the culprit from the very get go. That was the issue it looks like. I’m about to reuse the old plugs, swap 2 plugs from the other set and try it out. Yes I’m gapping to .28.

If this works I’m definitely sending Precision Raceworks and email. Hopefully I can get a new set of plugs or a refund. And hopefully they can test them there before they ship them to me. Good thing I only live 57min away from them.

[eeyang92]

Originally Posted by Leaveatrail86

So I went ahead and test the new spark plugs I bought from Precision Raceworks. Three are weak, 2 are bad and only 1 is good.

4.45, 4.28, 4.26, 4.61, 4.49, 4.47ohm’s. These plugs have less than 100 miles. Go figure. Quality control, fakes or junk?

The old plugs were 97506 as well but purchased from Burger Tuning.

5.11, 5.03, 4.47, 4.84, 4.62, 4.18. Old plugs. I was better off with the old plugs. The 4.18 I’m guessing was the culprit from the very get go. That was the issue it looks like. I’m about to reuse the old plugs, swap 2 plugs from the other set and try it out. Yes I’m gapping to .28.

If this works I’m definitely sending Precision Raceworks and email. Hopefully I can get a new set of plugs or a refund. And hopefully they can test them there before they ship them to me. Good thing I only live 57min away from them.

Hopefully it works out for you! I never realized there could be so much variability between each cylinder on old plugs.

[AmuroRay]

Just go with OEM plugs, why try to make these work?

[ericlr1225]

Originally Posted by F87source

1) Just because one user has success with a plug gap range doesn't mean you should follow it because every car and use case is different (maybe one car had weaker coils), and especially because you also have much more powerful coils meaning you have alot more potential to chose larger gap sizes. This is why you always go to the max gap (stock) and go down only when needed, so you can get the largest gap size possible - remember gapping down is not a desirable thing it means you don't have the coil energy to maintain the spark. So when you follow another user's gap size choice without any prior testing on your own setup - especially when you are following a gap size utilizing stock coils on a much more agressive setup (meaning the requirements for a smaller gap may be valid) you are literally throwing away all the gains you have by upgrading coils because you don't need to gap down. Sure 0.026" doesn't seem to pose any issues with misfiring or idle, but again why would you gap down when it's not needed - this is even more emphasized because you have upgraded coils and gapping down when you don't need to is like throwing money for coil upgrades in the garbage. (Sorry if I sound harsh, I'm just trying to explain this as best I can, not trying to be a douche).

But at the end of the day it's your choice, I just think it's a bad idea to gap down when not needed.


2) Did you put anti-sieze on your spark plugs?

3) Wait wait wait, you did what? NEVER unplug the pre cat o2 sensor, that is what the car uses to detect afr's, removing this cripples the cars ability to accurately detect these values and can put it in limp mode or even worse blow the motor.


If the cat is fouled afr's values would be very off, and you may get codes.

Feeling nice to find this thread and thanks for the info. It may solve my current problem. Funny part is I'm under a custom tuning process of Cary Jordan Team right now. LOL. They insisted 0.022'' gap new spark plugs must be changed first, then ask them to start tuning process.

[F87source]

Originally Posted by ericlr1225

Feeling nice to find this thread and thanks for the info. It may solve my current problem. Funny part is I'm under a custom tuning process of Cary Jordan Team right now. LOL. They insisted 0.022'' gap new spark plugs must be changed first, then ask them to start tuning process.

Yeah, you never gap down plugs when it is not necessary, you only gap down if you are misfiring due to the spark being blown out. Because the key to spark plug gap is as big as possible without blowing out, this way you promote better combustion and avoid rough idling and misfires.

There is no such thing as a one size fits all gap, so I hate the idea of just following an arbitrary size, you must do what works best for your car.

[ericlr1225]

Originally Posted by F87source

Yeah, you never gap down plugs when it is not necessary, you only gap down if you are misfiring due to the spark being blown out. Because the key to spark plug gap is as big as possible without blowing out, this way you promote better combustion and avoid rough idling and misfires.

There is no such thing as a one size fits all gap, so I hate the idea of just following an arbitrary size, you must do what works best for your car.

I'm trying to run stage 2 91 tune with pump gas consistantly. FBO, no E85 until I decide to upgrade HPFP in the future.

What gap do you think is relative best for me? 0.028''?

[F87source]

Originally Posted by ericlr1225

I'm trying to run stage 2 91 tune with pump gas consistantly. FBO, no E85 until I decide to upgrade HPFP in the future.

What gap do you think is relative best for me? 0.028''?

Yeah you should be fine with that gap, I've seen alot of people run more power than stage 2 91 with the same gap. But this will depend on the health of your coils, so it is all relative.

[shaneguags]

Originally Posted by F87source

0.030".

Yeah the gap is supposed to be that big, which is what shocks me when there are users running 0.018". Like that can't be running smoothly.

I'm using 0.018 for an E60 blend and car feels smooth. I actually had misfires with 0.020 on the top end, causing us to gap down more. we also had to dial my map in better. the car feels fine now for me but we are fixing my reflex box

[ericlr1225]

quick question, what is misfires symptom? CEL on? I don't have rough Idle or Stall issue. How can u tell if it's misfiring when doing WOT or during regular driving?

[shaneguags]

Originally Posted by ericlr1225

quick question, what is misfires symptom? CEL on? I don't have rough Idle or Stall issue. How can u tell if it's misfiring when doing WOT or during regular driving?

mainly with WOT throttle pull. we datalog with 4 gear pull, 2k to 6k RPMs. the car will cut all its power out basically and feel like it redlined it. sometimes it'll throw on a CEL but not always. rough idles can be from the same symptom of the misfire, like spark plugs, coil ignitions, or injectors.