Spark Plug Diagnoses

[Lextreme II]

What do you guys think of these spark plugs? They are Denso Iridium with .032" gapping. These are from my car running 14 psi daily.

 

[cowboy bebop]

How many miles are on the plugs? Is the groove in the group strap supposed to be there? They look like you're running a tad rich. : )

Eric

 

[cjsupra90]

I agree with Eric, they do look a little rich. Maybe it the pitchure deceiving me, but they also look a lot bigger then .032 on the gap. Outside of that they dont look that bad. Another thing to try is dropping the gap down to .028

On a side note, I personally along with a few other people that I know of have had problems with running Iridium Plugs on turbo motors.

 

[Lextreme II]

Got some help from Toysmre and he recommended a colder plug. I also found out Supra TT plugs are the same. I am using NGK6079 with .030"

 

[SCV8]

They look pretty good to me, all things considered, maybe a little rich, but that's better than not knowing. After all, there's likely a point where things are leaner, and if you were any leaner overall, that point could be a problem.

I have begun using a surface fire plug in my daily driver Corolla , the same plug as 2000 truck V6s came with, they add some power down low at least, not sure about the top end.
Don't the Supra guys use copper plugs, and replace them often?

 

[Toysrme]

Honestly they look a lot better than I would have figured.
Iridium plugs are much better than I figured under boost after reading how many supra guys use NGK Iridium's & the equiv Denso IK20 & IK-22's.

Anyways. I'm not sure it's fuel on the plug at all. Iridium plugs clean themselves really well. I'm more inclined to think that's oil from all the blow-by & turbo seal junk he had going on. Tho we know he's pig rich, My first thought is that the hot stock plugs doing bigtime heat under boost would be able to burn any fuel off.
You can see that the tip of the iridium plug & the strap are doing fine.

I'm pretty dumb, I can't see gaps in pictures.

The stock plug is your generic 0.44 gap. So .31-.35 under boost sounds great. Then if there's spark blow-out, drop it to .28. I'm jsut a little hesitant to tell him to do that right off the bat. That's getting pretty small (Tho not uncommon at all for modified turbo cars.).



The good old copper core plugs 1 range colder @ dollar, or two a plug are the msot popular for the supra crowd. NGK BKR7E's # 6097.

 

[Lextreme II]

Here is a good article on Spark Plug Anaylsis From the anaylsis above, looks like the plugs were running rich initially and now its running better so it shows some residual of richness and also have signs of normal appearance.

 

[jgscott]

Lex I think the one step coolder plugs are the thing to run on Boost or Nitrous. Are the Supra plugs one step colder ? I was running some Zex colder plugs that I got from Zex. They also had some kind of sheild or something is case of detonation, that no plug material would come apart in you combustion chamber I think. Think they were about $ 65 for 8 and they worked very well. I can get the Zex part # if you want.

 

[Lextreme II]

I had Iridium but now I have NGK and I love it. Less than $15 for a whole set.