fe9_fe9

I suck in decoding Spark Plugs and I pulled the plugs out and they all looked like this one. These are TR7IX's and I didn't gap them. I'm planning to replace them with a set of BR7EF's and I'm going to gap them at 0.030. What do you think?

I really appreciate all input

DSteck

You really need to put in a fresh set, then take the car out and do a good, long winded third and fourth gear pull. Shut the engine off after the pull and yank the plugs.

You should get a magnifying glass and look at the porcelain. Check it for little diamond like speckles.

robertaj

uhhh so what new engine you thinking of buying? Better start planning ahead... because looks like your running lean!!!!!!!!!!!!!!

I would get the car tuned immediately... what mods do you have?

Streetk14

I really think that depends on what he was doing with the car before he pulled the plugs. If he was just cruising around or idling before he pulled them, I think it's pretty normal for them to appear "lean".

I could be totally wrong, of course

BoosterClub

I would never advise against caution, but this guy is nuts saying your plugs definitely indicate you are running engine blowingly lean. They do not.

robertaj

I'm not saying he will blow it tomorrow, that was a joke but definitely looks like he is running lean and should check it out sooner then later.

I just pulled mine a few weeks ago and changed then on a supercharged c6 and they look nothing like that

madmax4499

reading plugs is like a lost art. there is a lot to it. google and read, unleaded fuel makes it even harder to read them. now that widebands are more common the only thing i check my plugs for is detonation " could crack or even leave little bits of the piston on the insulator" oil in the combustion chamber "peppering." the coloring on the ground strap will also give clues on your timing.

BoosterClub

Just because they don't look like your plugs doesn't mean his are super lean. From that view your plugs look like they are too rich/too cold for the application. But the fact is from one angle without anything obvious, it's pretty damn hard to tell for sure either way.

madmax4499

http://www.dragstuff.com/techarticle...ark-plugs.html

this touches on the finer point of reading.

you will need something like this to read them properly

http://www.pro-system.com/sparktool.html

user_name

Use 2 different widebands on the dyno, and just read the timing strap on the plugs. This method leaves me confident I have a car dialed in. Make multiple pulls on the dyno, and shut it down without much idling.

DSteck

Lol. So because the porcelain isn't black as night, he's too lean? I've NEVER pulled a set of plugs out of any car I have ever tuned that look as black as that.

Fuel is read off the base ring anyway. You're high if you think you can read fuel from the pics he posted.

robertaj

No not because its not back, but rather because its WHITE. That is an indication of being lean.. It could be the picture or possibly a flash making it look that way but I would have it checked out and not assume anything.

And if you have never seen a get of plugs "as black as that" you probably have never pulled a set of plugs in your life.

PS they are a nice brown color not black maybe I should have used a flash lol

DSteck

I pull plugs a lot, and know that they should never come out looking like your's. I also know you can't read a plug properly after putting around town.

Just for you, I'll pull a BR8 out of my Z06 which has street miles on it and show you exactly what it should look like.

Anybody who knows about reading a plug knows you can't read fuel off the porcelain. Sorry, but you should not be talking about this.


Edit: Here we go. This is one of the TR7IXs that was in my car at 16psi boost. 10.3 AFR on 93 and meth, 18* of timing. Still going to tell me it's too lean? This is how the plug looked when we did a fourth gear pull down the highway, pulled over, and checked it. Reinstalled it, drove the car for 1000 miles like that, and then pulled them out to put BR8s in to do glory pulls on the dyno. 930whp on this plug pictured below, < 2% fuel trims driving around town. Notice the BONE WHITE porcelain.

A proper plug should look brand new after it's pulled out from a WOT pull, aside from a timing mark and a fuel ring.

TWS Racing

The way we read plugs is:

1. Do a 1/4 mile pass at the track, SHUT the motor OFF on the return road and pull plugs.

or

2. Do a pull on the chassis dyno, SHUT the motor OFF, and pull a couple plugs to read.

If neither scenario is feasible, then you can go to a deserted stretch of good road. Nail the throttle and stay in WOT as long as you safely can but at least 6-7 seconds. Shut the car off and coast to a stop. Pull on your gloves and remove a couple plugs to read them.

fe9_fe9

Yeah thanks Dave. I didn't actually do anything like that Car was cold in the garage. Took it yesterday for a quick run since it was sitting there for almost a month. Noticed that there was a little bit of hesitation during the run and some white smoke blowing off the vented cap when I first started it. AFR was around mid to high 10's and timing was around 10*. So I thought I might pull the plugs out and see how things are going. I'm also planning to do a compression test while I'm at it. Pulled the plugs off last night and called off hehe. I'm gonna pick up tonight or tomorrow probably

Thanks Dave..

fe9_fe9

Thanks for your comments. Car was running anything but lean all the way. I actually tune my cars myself.

It's a 402 LS2 with a Twin Turbo and Meth, 91 Gas. Running 12 pounds at the moment.

fe9_fe9

Car was cold.. Thanks for your input

fe9_fe9

Thanks for the useful info

DSteck

I like your style.

fe9_fe9

Awesome resources