I installed NGK Iridium (LFR6AIX-11) 1-step colder plugs with the stock gap when I installed the Stillen stage 4 s/c. Have been running them for about 7 months and 9000 miles. Pulled them today to check them out because I had some pinging awhile back (now fixed). Looking at them, I think it would be a good idea to change them.

Stillen's install instructions recommend NGK Platinum (PLFR6A-11) 1-step colder plugs. I know that alot of guys with various FI setups are running iridiums though. I'm just trying to figure out what to get this time around.

Does it really make a difference which of these 2 I use? Could one possibly be any better for my setup than the other? If so, why? Thanks in advance

 

go for the NGK Copper plugs or the Iridiums......stay away from platinum for performance. Platinum, by nature, is not a good conductor. It is hard, which lends itself to longevity.

 

iridium and close the gap more then stock...supercharges tend to "blow out" the spark

 

From what I understand, you have to change out coppers much more often, right?


I thought iridiums were too sensitive or fragile to gap?

 

Platinum is very bad for turbocharged cars. Look it up, putting Platinum plugs in your engine can blow it up.

 

Why does Stillen recommend Plats then?

 

Platinum stores heat and will cause detonation in turbocharged engines. I actually made this mistake a few years ago and almost blew up an engine i had. The spark plugs were pitted.

 

He Doesn't Have A Turbocharged Car Lol.

 

That's correct. It's a supercharger. Does that completely nullify what you're saying then?

 

I have had platinums in for 11,000 miles and recently examined them and they were fine..

 

Iridiums

 

Supercharger and turbocharger are both forced induction. You are better off with iridiums or coppers. I actually prefer copper plugs. Copper is cheaper, like 1.50$ a plug. Even if you soak them with gas they will still spark unlike iridium. makes it nice to tune with to get a car running right at idle if you foul the plugs at first.

 

Posts #2 and #3 scare me....


That is almost sig worthy...

 

Platinum is not recommended with Nitrous. Iridiums are.

 

Your post is equally scary... Care to elaborate??

 

my buddy is a tech for nissan and he said with iridiums 1 step colder u should close the gap a bit more...i check mine every couple of months but this works the best for me...and y r our comments scary cupcake??

 

Any more opinions? Hopefully backed up with some theory or actual facts?

 

Yeah I have an opinion. I've heard that using copper is recommended because you want the spark plug to be a failing point. Copper is obviously the "weakest" of the 3 materials and will melt or fail before the other two.

In the event something were to happen that would cause cylinder damage, either to pistons, rods, valves, you name it, you'd want the spark plug to fail which would stop the combustion, or detonation process to prevent further damage.

An iridium will take the abuse and keep on sparking, a platinum even more so, but the copper would be the first to fail.

Please let me know if this makes sense, I may have worded it weird. Oh and I am speaking about FI application where more extreme detonations are expected (if they occur, when compared to "less extreme" detonations going NA).

 

0o0o0o.....im subscribing to this. Im installing my nitrous really soon, so I would definately like to know whether to use copper or iridium 1 step colder plugs.

 

Denson 1 step colder r realy good and here is 2 step colder as well..