Iridium plugs....
Re: Iridium plugs.... Go to densoiridium.com and find out for yourself. According to Denso, they do. They have a lot of info. I run iridiums but I can't really tell you if they're better tan coppers performance-wise. I took out the stockers because I was getting misfires at over 4500 rpms. I replaced them with Denso iridiums and MSD wires and the misfires went away. I heard they are the best plug to have when you are running FI or nitrous because of their high temperature resistance (melting point).
TECH Apprentice
Joined: Jul 2002
Posts: 393
Likes: 0
From: Tucson, AZ
Re: Iridium plugs.... I think the only real gain you can see with iridium is longetivity - copper plugs are to be changed often, but performance (conductivity) -wise copper is the best - that's a physics fact.
TECH Fanatic
Joined: Jun 2003
Posts: 1,070
Likes: 0
From: Further South than Hell
Re: Iridium plugs.... I run DENSO's and I will swear by them. One old trick is to "read" ur plugs. U can find out things like if you're running rich or lean (carbon deposit and color; which cylinder misfires(Fuel smell and deposit), burning oil (Oily deposits).
DENSO has the thinnest electrode on a plug and a groove which makes the spark travel a straighter path.
At 10-12 bucks a piece they are expensive but u don't have to change them as often. I've had mine for 20k. When tuning I just remove them and check gap (which I've never had to adjust) clean them a little and in they go again.
Iridium is the hardest substance in plugs today and require less spark energy to do the same job
Another favorite among LS1 owners are NGK T55s
DENSO has the thinnest electrode on a plug and a groove which makes the spark travel a straighter path.
At 10-12 bucks a piece they are expensive but u don't have to change them as often. I've had mine for 20k. When tuning I just remove them and check gap (which I've never had to adjust) clean them a little and in they go again.
Iridium is the hardest substance in plugs today and require less spark energy to do the same job
Another favorite among LS1 owners are NGK T55s
