Drag/Acceleration Mods to improve ¼ mile times and unofficial track thread

[Edmund]

Did the spark plugs change today with Denso IKH27. Fixed the misfire issue. Car is running fine and no coil pack damage. I will push the car to its limits to make sure the plugs are doing there job.

What plugs did you have before?
Gap?

Curious as to why 2 steps colder? Especially considering that you will be running WMI, which will suppress detonation. And should not require going so cold on the plugs... I would have though you would want to run oem plugs with WMI.

 

[Angel]

What plugs did you have before?
Gap?

Curious as to why 2 steps colder? Especially considering that you will be running WMI, which will suppress detonation. And should not require going so cold on the plugs... I would have though you would want to run oem plugs with WMI.

I had Denso IKH24 which are 1 step colder than OEM.

I installed Denso IHH27 which are 2 step colder and I gapped them to .024.

I am not sure to be honest. I know I fried 2 plugs doing 2 WOT pulls on WMI. I figured instead of replacing with the same I had on ( 1 step colder) I would move to 2 step colder and test how they perform.

I did as well but it seems like the Stinger can benefit from the colder plugs even if you have wmi. I never used wmi yet since I did those pulls. I wont be using wmi on daily driving I will be using it at the track only. I also got WMI to keep the valves clean.

 

[Regs120]

They told me to gap them to .022 but a gap size that much should not make a difference. These cars desperately need a ECU tune.

 

[Angel]

They told me to gap them to .022 but a gap size that much should not make a difference. These cars desperately need a ECU tune.

I mean I been running all my plugs on the Stinger between .024-.025. I have had very good results with this gap. I was told as well to use .022 but I just feel like that gap is bit tight for a daily driver.

Its your call, by no means am I an expert, just speaking from my personal experience.

 

[Regs120]

Yeah .022 seems to want to put a lot of stress on the electrical system. Which is why ECU tune can adjust the spark.

The only thing I can think of is the spark plug indexing was so far off and you were blocking the fuel spray from the injector. Enough fuel over time accumulated or by circumstance fried the spark when it had a chance to ignite. Make sure you are properly indexing your spark plugs when you install them.

All theory of course!

 

[Terry@BMS]

The lower the gap the less coil energy required to jump the gap. But the less potential spark energy. 0.022 seems to be the sweet spot. You can increase dwell time (how long you charge the coil before firing) with flash tuning but I'd tread really carefully. Easy to burn up a coil doing that.

 

[Angel]

The lower the gap the less coil energy required to jump the gap. But the less potential spark energy. 0.022 seems to be the sweet spot. You can increase dwell time (how long you charge the coil before firing) with flash tuning but I'd tread really carefully. Easy to burn up a coil doing that.

Do you see potential issues with .024 gap? Should I re gap to .022?

Just asking the question lol I already fried 2 plugs don't want to fry anymore.

 

[MrSmoofy]

Yeah .022 seems to want to put a lot of stress on the electrical system. Which is why ECU tune can adjust the spark.

The only thing I can think of is the spark plug indexing was so far off and you were blocking the fuel spray from the injector. Enough fuel over time accumulated or by circumstance fried the spark when it had a chance to ignite. Make sure you are properly indexing your spark plugs when you install them.

All theory of course!

Newb question, how do you actually index a spark plug first I've heard/seen anyone mention this in any of the spark plug threads.

 

[Tonkabob]

Since he blew plugs 2 and 6, its my theory that these 2 cylinders which are the furthest from the throttle body and meth spray are getting less water/meth and are running hot and lean. I think the plugs cold go again.

 

[MrSmoofy]

Newb question, how do you actually index a spark plug first I've heard/seen anyone mention this in any of the spark plug threads.

Holy crap, just watched a video on this and spark plug indexing washers. Those that are changing their spark plugs are you doing this?

 

[Regs120]

https://www.enginelabs.com/news/getting-ignition-spark-plug-indexing-101/

 

[Edmund]

Since he blew plugs 2 and 6, its my theory that these 2 cylinders which are the furthest from the throttle body and meth spray are getting less water/meth and are running hot and lean. I think the plugs cold go again.

I don't think that to be the case. He's injecting well ahead of the individual runners, and by that logic, there would also be less air going to those cylinders as well.

In viewing Angel's video, I noted that he used dielectric grease and anti-seize. The anti-sieze can contribute to overtorquing the plugs, and putting dielectric grease on the tip of the plug is bad. It should only be placed on the coil boot, or lightly on just the lower porcelain part. I think that he might have had too much grease on those 2 cylinders and caused the coils to fry the plugs.

 

[Edmund]

Holy crap, just watched a video on this and spark plug indexing washers. Those that are changing their spark plugs are you doing this?

Most of the indexing pertains to 2 valve head designs. Most if not all 4 valve head designs locate the plug in the center, and that is usually where the mixture is squished before being lit. I don't see much, if any, value to indexing on our engines.

But on my c6Z06, I definitely index the plugs!

 

[Tonkabob]

I don't think that to be the case. He's injecting well ahead of the individual runners, and by that logic, there would also be less air going to those cylinders as well.

In viewing Angel's video, I noted that he used dielectric grease and anti-seize. The anti-sieze can contribute to overtorquing the plugs, and putting dielectric grease on the tip of the plug is bad. It should only be placed on the coil boot, or lightly on just the lower porcelain part. I think that he might have had too much grease on those 2 cylinders and caused the coils to fry the plugs.

My theory is based on it being a dry intake and is designed to flow air. If the water/meth is not well vaporized its going to fall out of suspension in the air and end up in the closest cylinders. This is exactly what happened in the video below although their intake is more convoluted than ours.
He was also getting bogging at first which could also be too much fuel in some cylinders.

What is Nitromethane, Anyway? - Hot Rod Magazine
Scroll down a page and watch the video on intercooler vs meth. Meth did not work at all with that cars intake.

 

[Angel]

I don't think that to be the case. He's injecting well ahead of the individual runners, and by that logic, there would also be less air going to those cylinders as well.

In viewing Angel's video, I noted that he used dielectric grease and anti-seize. The anti-sieze can contribute to overtorquing the plugs, and putting dielectric grease on the tip of the plug is bad. It should only be placed on the coil boot, or lightly on just the lower porcelain part. I think that he might have had too much grease on those 2 cylinders and caused the coils to fry the plugs.

The original plugs I installed had no grease. I just gapped them to .024. The plugs that I installed yesterday I added the grease which is the video you watched.

I also used a torque wrench which I showed in the video. I torqued them 22-24 pounds per Kia manual specs.

Not sure the grease would cause any issues. It is made for that lol.

A little lube does not hurt anything...........

 

[Edmund]

...
I installed Denso IHH27 which are 2 step colder and I gapped them to .024.

I also got WMI to keep the valves clean.

Plug heat range is dictated by combustion temps. Generally speaking for every 100whp over stock, you should drop down a heat range. Unless the oem plug was a little too hot. Going 2 steps might be pushing it, unless you drive it hard regularly to clean off the deposits.

And that you will! I had ran wmi in my Legacy GT yrs back, and the car never had such squeaky clean internals. Not to mention it made the same power in the heat of summer like it did in the winter!

 

[Angel]

My theory is based on it being a dry intake and is designed to flow air. If the water/meth is not well vaporized its going to fall out of suspension in the air and end up in the closest cylinders. This is exactly what happened in the video below although their intake is more convoluted than ours.
He was also getting bogging at first which could also be too much fuel in some cylinders.

What is Nitromethane, Anyway? - Hot Rod Magazine
Scroll down a page and watch the video on intercooler vs meth. Meth did not work at all with that cars intake.

I need to watch this.

So what you are saying is don't do Meth? Because it can be useless in our Stinger?

 

[Angel]

Plug heat range is dictated by combustion temps. Generally speaking for every 100whp over stock, you should drop down a heat range. Unless the oem plug was a little too hot. Going 2 steps might be pushing it, unless you drive it hard regularly to clean off the deposits.

And that you will! I had ran wmi in my Legacy GT yrs back, and the car never had such squeaky clean internals. Not to mention it made the same power in the heat of summer like it did in the winter!

So in other words I should go back to stock plugs? What issues can a colder plug cause in my case? Is it just that they will go bad sooner and I need to keep an eye on them?

 

[Angel]

Plug heat range is dictated by combustion temps. Generally speaking for every 100whp over stock, you should drop down a heat range. Unless the oem plug was a little too hot. Going 2 steps might be pushing it, unless you drive it hard regularly to clean off the deposits.

And that you will! I had ran wmi in my Legacy GT yrs back, and the car never had such squeaky clean internals. Not to mention it made the same power in the heat of summer like it did in the winter!

I only plan on running wmi on the track.

Should I go back to oem plugs? Or buy the 1 step colder?

 

[Edmund]

The original plugs I installed had no grease. I just gapped them to .024. The plugs that I installed yesterday I added the grease which is the video you watched.

I also used a torque wrench which I showed in the video. I torqued them 22-24 pounds per Kia manual specs.

Not sure the grease would cause any issues. It is made for that lol.

A little lube does not hurt anything...........

Just trying to logically deduce root cause.

To each his own, but I would not recommend using antiseize on the threads, and only use dielectric sparingly on the porcelain only.