Colder plugs in the MS3, whose using them?

[SpdFreak]

NGK LTR7IX-11 is the plug I went with. Car is running great with no hiccups. Didnt cure anything to crazy. But car still runs good with a colder plug, which i think is a good sign. Ill know in the next few days about some more dyno info for you guys.

Isn't any car going to feel smoother and refreshed with a new plug, let alone a colder plug?

 

[fourthmeal]

I gotta think people are on to something here. Good going!

 

[Haltech]

1 Stage cooler plugs do have a rougher idle, but not very noticeable. When you hit 2 stage colder plugs, thats when you notice the rougher idle.

I would like to see his old plugs.

 

[driver311]

whos, mine?

 

[knowledge007]

Do you have a rough idle Driver? Or did your sputtering idle go away witht he new plugs?

 

[whooosh]

Do you have a rough idle Driver? Or did your sputtering idle go away witht he new plugs?

why would you get a rough idle with 1 step colder plugs?
I bet the farm that his idle characteristics are exactly the same as stock

Colder spark plugs help prevent knock when running higher boost levels. They also help run lower EGT's. Running too cold could cause pre-ignition. One step colder is recomended once about 50-75 hp over stock.

More in depth:

A spark plug's heat range has no relationship to the actual voltage transferred though the spark plug. Rather, the heat range is a measure of the spark plug's ability to remove heat from the combustion chamber. The heat range measurement is determined by several factors; the length of the ceramic center insulator nose and its' ability to absorb and transfer combustion heat, the material composition of the insulator and center electrode material.
The insulator nose length is the distance from the firing tip of the insulator to the point where insulator meets the metal shell. Since the insulator tip is the hottest part of the spark plug, the tip temperature is a primary factor in pre-ignition and fouling. Whether the spark plugs are fitted in a lawnmower, boat, or a race car, the spark plug tip temperature must remain between 500C-850C. If the tip temperature is lower than 500C, the insulator area surrounding the center electrode will not be hot enough to burn off carbon and combustion chamber deposits. These accumulated deposits can result in spark plug fouling leading to misfire. If the tip temperature is higher than 850C the spark plug will overheat which may cause the ceramic around the center electrode to blister and the electrodes to melt. This may lead to pre-ignition/detonation and expensive engine damage. In identical spark plug types, the difference from one heat range to the next is the ability to remove approximately 70C to 100C from the combustion chamber. A projected style spark plug firing tip temperature is increased by 10C to 20C.

 

[driver311]

No idle issue. I plan on running around 22psi on the stock turbo maybe more if it likes it. so I was just planning ahead. i just didnt know how the disi motor would like them. No problems at all though. I recommend them to anyone pushing over 18psi on pump gas.

 

[tru-boost]

so let me make sure i understand this correctly. this helped the slight sputtering that sometimes comes in at WOT with lots of boost ? my car will do this same sputter ever so slightly, a few seconds before i hit my big fall on my ass cut at about 5k. i assume you still have the cold weather cut at the top end right ? it just smoothed things out a little. i am considering the plugs, but am not really sure it will do anything for me.
and is that a copper plug, or iridium. and did you have to gap them ?

 

[Haltech]

whos, mine?

yup

 

[Haltech]

why would you get a rough idle with 1 step colder plugs?
I bet the farm that his idle characteristics are exactly the same as stock

Colder spark plugs help prevent knock when running higher boost levels. They also help run lower EGT's. Running too cold could cause pre-ignition. One step colder is recomended once about 50-75 hp over stock.

Actually, its very common for an automobile to react to change in spark plugs, even one stage colder. This has to do with the idle burning charactertics of the plugs themselves. Some cars/trucks, react different than others, especially in forced inducted applications.

More in depth:

A spark plug's heat range has no relationship to the actual voltage transferred though the spark plug. Rather, the heat range is a measure of the spark plug's ability to remove heat from the combustion chamber. The heat range measurement is determined by several factors; the length of the ceramic center insulator nose and its' ability to absorb and transfer combustion heat, the material composition of the insulator and center electrode material.
The insulator nose length is the distance from the firing tip of the insulator to the point where insulator meets the metal shell. Since the insulator tip is the hottest part of the spark plug, the tip temperature is a primary factor in pre-ignition and fouling. Whether the spark plugs are fitted in a lawnmower, boat, or a race car, the spark plug tip temperature must remain between 500C-850C. If the tip temperature is lower than 500C, the insulator area surrounding the center electrode will not be hot enough to burn off carbon and combustion chamber deposits. These accumulated deposits can result in spark plug fouling leading to misfire. If the tip temperature is higher than 850C the spark plug will overheat which may cause the ceramic around the center electrode to blister and the electrodes to melt. This may lead to pre-ignition/detonation and expensive engine damage. In identical spark plug types, the difference from one heat range to the next is the ability to remove approximately 70C to 100C from the combustion chamber. A projected style spark plug firing tip temperature is increased by 10C to 20C.

Again, operating temperatures do vary at idle. Colder plugs do have a lower heat during idle as well as the entire power ban. This is why during high boost applications, youre less prone to detonation damage with colder plugs because the heat in the combustion chamber wont affect the operatating temp of the plug at its maximum spark. You can feel stumbling at idle with colder plugs because they are actually misfiring with the temp difference in the combustion chamber. Again, this varies from vehicle to vehicle and whether the plug is Iridium or Copper, it doesnt matter. I have heard Irdidium is less prone to idle misfires but ive never experienced that using Densos. I could still feel it and see it on datalogs with my truck.