I'm about to replace my spark plugs and wanted to find out if upgrading to iridium plugs is worth it. Mods on my car are 1/2" Motordyne spacer, Stillen dual cat back, grounding wires, z-tube and amsoil filter.

I'm currently looking at the NGK Iridium IX(#LFR5AIX-11). Will I see a difference if put these on from the stock plugs? If yes, what?

Feedback greatly appreciated.

 

I doubt there will be any difference, just won't have to replace them as often.

 

My thinking is this... If your gonna replace something, replace it with something better than what was there. Get the iridiums. That's what I run.

 

In general terms, I like your thinking. Especially, if it is for your own use.

 

i almost bought Denso Iridiums for N/A engines - the deal fell through because of the problems with supplier. they are more expensive than regular plugs, but also are quite a bit nicer, with improved design. and Denso claims ~5% performance boost. w/e, but i'll take it.

 

Guys

This place has the best deals. They had the NGK Iridium's on sale for 6.49 each
When I bought them. Great company. Here is a picture of the stock plug, and the Iridium LFR5AIX-11. My guess is, I could of gone one step colder.
Happy holidays.

http://www.clubplug.net/index.html?h...net/cross.html

 

i just bought a set of Denso plugs from www.clubplug.net - awesome price, at $11.20 apiece.

here's the direct link to the "add to cart":

http://www.aitsafe.com/cf/add.cfm?us...o.html&units=1

enjoy

 

Just got done installing new NGK iridium plugs. What a b*tch to install! Getting all the crap out the way to get to the ignition coils was the hardest part otherwise it's an easy install. Haven't taken her for a spin yet, so cant' say if there will be any noticeable difference from the stock platinums.

On another note, I tried replacing my drive belts but gave up because I couldn't loosen the idler pulley lock not. Will take her to a shop to do it for me.

 

What, precisely, does going colder do to your engine's operation?

 

Here's a direct quote from NGK's web site on the colder plugs:

"Conversely, a cold spark plug has a shorter insulator nose and absorbs more combustion chamber heat. This heat travels a shorter distance, and allows the plug to operate at a lower internal temperature. A colder heat range is necessary when the engine is modified for performance, subjected to heavy loads, or is run at high rpms for a significant period of time. The colder type removes heat more quickly, and will reduce the chance of pre-ignition/detonation and melting or damage to the firing end. (Engine temperature can affect the spark plug's operating temperature, but not the spark plugs heat range)."

 

And to add to this, if you go too cold of a plug, then it will foul more easily and ruin it.

 

I think I'm running lean. Going colder will help that, correct?

 

There is an old term used that says, "Lean is mean" The only true way to figure out what you need is to pull your plugs. There is not much at all to be gained by going to a colder set of plugs in a N/A car. In fact sometimes having a colder set of plugs can cause some big problems with detonation. If the plugs let deposit to build up, the deposit can start to glow and cause pre ignition (not good) As compression goes up so does the heat in the cylinder. If the plugs are to hot, they can't dissipate the heat and start to glow and burn up if you let it go to long. You will see the drag race boys play with this between runs. My personal belief is with the VQ and what I've seen so far is one step colder should be just fine as long as you keep you engine under spirited driving conditions. No magic here, just good tuning practices.