I hate to bring up another sprk plug thing, but can you look real quick?

[jbrinkley]

carrera stock plug (bosch#7). I'm looking at the discoloration on the prong. Does that mean something important?
I have bosch 7's 6's and 5's, so should I jump down one range or stick to stock or go with the 5's.
this is a stock compression turbo carrera boosted to .6bar
these are pic of one plug, all of them look the same

[930gt-40r]

you may want to go to a cooler plug and add some fuel, she looks a little lean. The discoloration on the ground strap almost looks like it was getting real hot.

[WydRyd]

I concur... the plug is too hot for your boosted application.

You really should be running a proper turbo plug for your motor. I use to run W3DPO's even in the low boosted bolt-on config, but I know they are priced like GOLD (platinum plugs are the best), so intead you could go with some W3CS or W4CS plugs, or W3DPO equivalents in the NGK range.

[jbrinkley]

some things I've found since yesterday. And some I've had in my bookmarks.

http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html
http://www.4secondsflat.com/Spark_plug_reading.html
http://www.centuryperformance.com/spark2.asp

And of course the back inside cover on a haynes manual.
Either way I put in some sixes in last night and I'll look at em again after a freeway run and go from there. Next time it'sd sunny.
Thanks for the comments. I'll post pics after i check the sixes and then the fives. I can't see jumping down 4 heat ranges to the bosch three's. The plug doesn't look that bad in my opinion. But I'm no expert

[jbrinkley]

O, I forgot to say, from what I've read the discoloration on the strap is a timing indicator, is this wrong?

[930gt-40r]

I cant remember what the discoloration meant depending where it was on the plug, but it could defenatly be an indicator of where the timing is as well

[Jim2]

Ground electrode displays mixture, center electrode and porcelin displays temperature.

[930gt-40r]

I see, that makes sense

[mb911]

I have been told by some experts that "reading" plugs really does not mean much with the newer fuels coloration is not the same as it was years ago. to me the picture shows a perfect burn but like I said that means nothing

[930gt-40r]

This also makes sense, the wide band, EGT, and Knock sensor all tell the whole truth and nothing but the truth.

[NathanUK]

I am no expert but I was thinking those plugs looked OK...

[jbrinkley]

me to. But, I'll compare with one range lower and then one lower still and see what they look like

[WydRyd]

Hmmm, I'd say if you're not seeing any pinging and all your AFR's are in check, then I wouldn't worry too much if I were you. A tan colored plug is a good sign of a clean burn, but from what I've been told, earlier turbo's require a colder plug than the typical 7s 6s or 5s.

[jbrinkley]

everything looks good egt, afr, just want to be sure ya know?
no one's ever talked about which ones for a carerra T, so I guess I'll find out. I bet Todd's done this before, and I suppose a phone call would answer the Q.
we'll see, But Merv, what does proto say about plugs?

[mede8er]

Your plugs look fine...IMHO....

[WydRyd]

Originally posted by jbrinkley
I bet Todd's done this before, and I suppose a phone call would answer the Q. we'll see, But Merv, what does proto say about plugs?

Todd recommends the W3DPO's for all the power levels for the 3.2 Carrera. They are the best, and fire reliably with the OEM ignition. He also recommends the W3CS plugs, but they might be a bit harder to fire with the stock ignition @ higher power levels, so you'd need an aftermarket CDI to fire those reliably when you step up to the big power systems.

One thing is certain, the stock Carrera plugs are too hot for the boosted configuration.

I'm running W4CS in my motor and they seem fine I'll probably step down a notch to the W3CS when I change plugs next, as they are in the right heat range.