Spark plugs.

[TeflonG35]

My knowledge of spark plugs really isent that great and this topic has probly been touched before but im lazy.

Will adding spark plugs that are one stage colder hurt an unboosted car? I see that superchargers and such need plugs that are one stage colder, i plan on adding a supercharger in the future and i need to change my plugs. Would it be wise to just go 1 stage colder and save some money and time?

Also are the iridiums worth the 50% cost over the the standard NGK? Do they add gains over standard or are they just less corrosive?

[cweberj30t]

You could go with the colder plugs and not hurt anything. I found Iridiums from Advance auto for $6.99 a plug. The funny thing is they had them on there for $12.99 as well. I guess it was a mistake on their part, but I got them for $6.99. I must say I am very happy with the Iridiums. Seems to idle smoother, shift better at high rpms.

[rn79870]

If I remember correctly, one of the differences in heat range is the reach of the electrode into the cylinder. The further the reach, the hotter the plug. One step colder should cause no real problem. If a problem occurred, I would bet it would be related to fuel or oil fouling. (This info is from my days a hundred years ago with a Husqvarna 400 and desert racing - where the art of reading the plug and changing carb jetting was a needed skill).

[BrandAidDesignG35]

Hey cweberj30t... I checked your cars, Nice set man!

Oh, about plugs, ahh, I'm too lazy to change mine right now...

I mean too busy

[C-Kwik]

If I remember correctly, one of the differences in heat range is the reach of the electrode into the cylinder. The further the reach, the hotter the plug. One step colder should cause no real problem.

Actually the plug's reach will be the same. Colder plugs just have the insulating ceramic nose attach to the metal thread shell closer to the electrode. This allows a more direct heat transfer path out of the plug into the cylinder head. By contrast, a hotter plug has a ceramic nose that attaches deeper inside the shell which limits heat transfer some.

[C-Kwik]

You could go with the colder plugs and not hurt anything. I found Iridiums from Advance auto for $6.99 a plug. The funny thing is they had them on there for $12.99 as well. I guess it was a mistake on their part, but I got them for $6.99. I must say I am very happy with the Iridiums. Seems to idle smoother, shift better at high rpms.

I'd bet money your iridium plugs only have an iridium center electrode with a nickel ground. As the G35 has a distributorless ignition system, expect the ground electrodes to wear prematurely.

[cweberj30t]

I'd bet money your iridium plugs only have an iridium center electrode with a nickel ground. As the G35 has a distributorless ignition system, expect the ground electrodes to wear prematurely.

NGK Iridium IX's. Sorry I wasn't more clear on that. I wouldn't use anything but NGK period.

[cweberj30t]

Check it out. The part number 4469 is $6.99 and the part number LFR5AIX11 is $12.99. Same plug, NGK Iridium IX. Just thought I would pass the savings on to other NICO members.

http://www.partsamerica.com/Pr...Plugs

[C-Kwik]

NGK Iridium IX's. Sorry I wasn't more clear on that. I wouldn't use anything but NGK period.

I'd use the NGK double platinums over the Iridium IX's though.

http://www.sparkplugs.com/glos...=0&pt=

and

http://www.sparkplugs.com/spar...fid=0

[C-Kwik]

I just got my own spark plugs in today. It's for my Titan, but should be the same plug for the G35. Here is a close up of the Denso SK plug's electrodes.



If you look closely, there is a small platinum disk on the ground electrode. Sorry if it is hard to see, but I took it on my camera's macro mode which had a hell of a time focusing when taking the picture at an angle.

Also, I got some NGK Iridium IX for the motorcycle.

[joshcloud9]

Are you 100% sure that they are the same plug?One looks like it's a "Double platinum" and the cheaper one has a differfent part NGK number? From NGK's site:

NGK IX iridium 4469 LFR5AIX-11 .044" $8.00 NGK Double Platinum 6240 PLFR5A-11 .044" (Original Equipment Manufacturer, and/or Original Equipment Service Part) $11.71

Check it out. The part number 4469 is $6.99 and the part number LFR5AIX11 is $12.99. Same plug, NGK Iridium IX. Just thought I would pass the savings on to other NICO members.

http://www.partsamerica.com/Pr...Plugs