Spark plugs.

SmsDetroit

SmsDetroit

Goblin Guru
I have a stock engine with a K04 turbo on it. I put a tune in last year from someone else on the forum. It went from running around 15 pounds of boost to 22 pounds of boost. It runs fantastic and pulls hard. However, sometimes at the top of first and second gear it breaks up. It’s got me wondering if I need to go to a different spark plug in a smaller gap. We sent my wife’s car to Linginfelter two years ago and they did a cat back and a tune on it. Her ATS-V went from running 17 pounds of Boost to 24 and they had to step the plugs down and close the gap because the boost was blowing out the spark on the plugs. Is it possible I’m experiencing the same thing. Also, if so, what plugs should I use.
 
Desert Sasqwatch

Desert Sasqwatch

Goblin Guru
By step the plugs down were they saying run a colder plug or one with a smaller electrode gap? Spark plugs have many variables from hot (projecting nose center electrode) to cold (recessed nose center electrode) and fixed spark gap to adjustable spark gap to name a couple differences. Turbos running higher boost typically use a colder spark plug and a smaller spark gap - I have to assume this is what was being explained.

This may help explain what I'm trying to convey:


Best advice, start with a spark plug one step colder than the stock Ecotec plug and see if it cures the problem.
 
Sluggonaut

Sluggonaut

Goblin Guru
I'm not sure running colder plugs will help with cutting out, as it's not likely due to a heat issue.

I'd start by decreasing the gap before changing plugs. I had to do this in a centrifugal supercharger setup before.

It can also be fuel-related so if the problem persists don't keep decreasing the gap too far as you'll end up with a weak spark and probably won't run well at any RPM. You may need to do the go-pro fuel pressure gauge method of checking your fuel pressure while driving if adjusting the plug gap or changing plugs doesn't fix the issue.
 
SmsDetroit

SmsDetroit

Goblin Guru
Sluggonaut said:
I'm not sure running colder plugs will help with cutting out, as it's not likely due to a heat issue.

I'd start by decreasing the gap before changing plugs. I had to do this in a centrifugal supercharger setup before.

It can also be fuel-related so if the problem persists don't keep decreasing the gap too far as you'll end up with a weak spark and probably won't run well at any RPM. You may need to do the go-pro fuel pressure gauge method of checking your fuel pressure while driving if adjusting the plug gap or changing plugs doesn't fix the issue.
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I’m thinking it’s spark because when it happen I get some black smoke
 
Stretch2126

Stretch2126

Well-Known Member
I went to a colder plug on a ko4 (lnf). It has the stock gap but I haven’t had any misses like that before.
 
Rttoys

Rttoys

Goblin Guru
You might have a coil breaking up. If you can data log, you might find a misfire happening under load. Not enough to set a code, but enough to feel it.
 
Stretch2126

Stretch2126

Well-Known Member
Rttoys said:
You might have a coil breaking up. If you can data log, you might find a misfire happening under load. Not enough to set a code, but enough to feel it.
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I did have a coil go out once and when I got into boost it would break up real bad. If there’s a code you can swap the coils around to single it out. I’ll send the plugs in a minute I should have the box at home.
 
Stretch2126

Stretch2126

Well-Known Member
Here’s the NGKs I run now. I run the car at autocross semi frequently so I figured stepping it up to fight knock possibilities wasn’t a bad idea. They’re expensive at Oreilly. I think they’re cheaper on rock auto if you don’t need them in a rush.
IMG_3045.jpeg
 
Indy Lonnie

Indy Lonnie

Well-Known Member
I was told by ZZP to run the stock plugs and stock gap. ZZP has had bad luck with any other plug. I have a set of NGKs in the garage - never installed. *Wonder if are tunes are similar?*
 
SmsDetroit

SmsDetroit

Goblin Guru
Indy Lonnie said:
I was told by ZZP to run the stock plugs and stock gap. ZZP has had bad luck with any other plug. I have a set of NGKs in the garage - never installed. *Wonder if are tunes are similar?*
Click to expand...
I am running your tune. Have you ever done the no lift shift? If so do you get and misfire during the 1-2 shift?
 
Indy Lonnie

Indy Lonnie

Well-Known Member
I’m in the process of replacing my clutch - because if I no lift shift it will slip. I have never had a NLS issue. There are threads out there pointing to the plugs causing the issue. Also- make sure it is above 185* coolant temp before you get into boost - otherwise it will fall flat on its face.

LNF- Misfires, stumbles after no-lift-shift

Ok I've searched here, the Solstice and Sky forums, LNF forum, etc, I've found plenty of people mentioning this happening but nowhere have I found the answer why or what fixes it. I'll do a high rpm, full throttle no lift shift from 1st to 2nd and when it goes into 2nd it will miss, sometimes...
forum.hptuners.com
 
Stretch2126

Stretch2126

Well-Known Member
My gap on my NGKs are .030 as well I believe. I don’t NLS just because I don’t want to wreck the input shaft.
 
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