Changed plugs today, opinions on these?

[Birddog]

They look a little lean to me but no pepper on the ceramic so I guess they're ok(?)...


#1

#2

#3

#4

Basically a "stock" 86 GLHS 2.2, +20s, 15 lbs most of the time, never sees less than 93 octane.

[turbovanman²]

#4, the tan one looks good. The others could be a tad lean but it also looks like it could be a light coat of oil. Either way, doesn't look too bad at all.

[Birddog]

They actually all have a slight tan tint in person, just lighter than I expected.

(#4 is technically #1 since I screwed up while checking cam timing a few months ago and put the distributor in 180 off...)

[BadAssPerformance]

I'd say a little lighter than they should be with the 42pph injectors. Only 15psi... Which logic module? how much timing?

[Birddog]

Sometimes up to 22 lbs, MP stage II module, base is at 12*, 225 pump, stock rail with an FM AFPR(previously sourced from a CL member so I'm not sure), clamped MAP.

[BadAssPerformance]

Are you sure those are 42pph injectors? If so, what is your fuel pressure set at?

[mo' parts]

definitely look a little lean for cast pistons....
mine look a little better than those running 16 psi on a stock fuel system, basically same set-up as you.

[johnl]

Reading plugs is getting to be a bit "old school" with the advent of wide band A/F sensors, EGT, and data logging. That said -

Get a magnifying glass, or a loop (like jewelers use), or even one of those ear doctor lookie thingies, or a magnifying plug light like this -

http://cgi.ebay.com/ws/eBayISAPI.dll...e=STRK:MEWA:IT

Only when you magnify what you are looking at can you REALLY see what's going on. In my experience with motorcycles (not turbos - and that's a BIG caveat), in brief, what you generally want to look for are:

(1) pepper (no good) - as you mentioned - indicates that specks of carbon were detonated off of the piston or chamber roof and blasted/vaporized onto the insulator where you see it stuck there,

(2) tiny balls of aluminum (very no good) indicates that somewhere in the chamber/piston it was so hot or there was so much detonation that the aluminum is being blasted/vaporized off of the piston/head and then after swirling around it happened to condense onto the insulator or the ground electrode or even the hot center electrode,

(3) slight melting (no good) of the sharp edges (that come on new plugs or that you touched up with a small sharp file before you re-installed the plugs) of the corners of the face of the ground electrode and of the center electrode, and

(4) a clean - bone white - insulator is OK (so long as NONE of 1, 2, or 3 are seen) BUT you must see a "mixture ring" - a nice dark brown or black ring of soot surrounding the base of the insulator. To see it, look down into the very bottom of the plug where the insulator meets the plug casing. If the ring rises up from the base (or covers the whole insulator) - too rich. If there is no ring - too lean - and you then will likely see 1, 2, or 3. A darker insulator color in general is hard to interpret as it can mean lots of things - blowby/oil, rich, seasonal fuel components/additives, etc.

You can't use this method if you don't do a clean WOT plug chop. You just won't get a reliable reading of the engine's mixture from the mixture ring unless you shut the engine off at the end of a good long WOT pull and coast to a stop and then pull the plugs for a read. No off WOT running allowed.

In my experience, if you have clean burning gasoline, a clean brand new looking bone white insulator and NO sign of 1, 2, or 3 AND you see a nice mixture ring at the base, then you are making maximum power for the setup.


I used this method for two days, of as fast as she could go track days at last year's Shelby American Auto Club event at Las Vegas - several hours of 16 -18 pounds through a stock (except Stg2 cal and G valve) GLHS. Turned the boost up as I increased from 100% 91 octane California pissgass by adding racetrack gas until we were at 100% race gas. She ran great. Drove her home. Still going strong.

[Birddog]

Are you sure those are 42pph injectors? If so, what is your fuel pressure set at?

I'm sure they're 42s(495s) I bought em new in MP blister pack at the NMRA/NMCA last year and popped em in that weekend(whatever was in there originally... I don't know the whole number, it ends in 642).
Right now idle pressure is at 50lbs.

WBO is on order as is a set of DSM/RC injectors, should be here friday and in by July...

Reading plugs is getting to be a bit "old school" with the advent of wide band A/F sensors, EGT, and data logging. That said -

Get a magnifying glass, or a loop (like jewelers use), or even one of those ear doctor lookie thingies, or a magnifying plug light like this -

http://cgi.ebay.com/ws/eBayISAPI.dll...e=STRK:MEWA:IT

Only when you magnify what you are looking at can you REALLY see what's going on. In my experience with motorcycles (not turbos - and that's a BIG caveat), in brief, what you generally want to look for are:

(1) pepper (no good) - as you mentioned - indicates that specks of carbon were detonated off of the piston or chamber roof and blasted/vaporized onto the insulator where you see it stuck there,

(2) tiny balls of aluminum (very no good) indicates that somewhere in the chamber/piston it was so hot or there was so much detonation that the aluminum is being blasted/vaporized off of the piston/head and then after swirling around it happened to condense onto the insulator or the ground electrode or even the hot center electrode,

(3) slight melting (no good) of the sharp edges (that come on new plugs or that you touched up with a small sharp file before you re-installed the plugs) of the corners of the face of the ground electrode and of the center electrode, and

(4) a clean - bone white - insulator is OK (so long as NONE of 1, 2, or 3 are seen) BUT you must see a "mixture ring" - a nice dark brown or black ring of soot surrounding the base of the insulator. To see it, look down into the very bottom of the plug where the insulator meets the plug casing. If the ring rises up from the base (or covers the whole insulator) - too rich. If there is no ring - too lean - and you then will likely see 1, 2, or 3. A darker insulator color in general is hard to interpret as it can mean lots of things - blowby/oil, rich, seasonal fuel components/additives, etc.

You can't use this method if you don't do a clean WOT plug chop. You just won't get a reliable reading of the engine's mixture from the mixture ring unless you shut the engine off at the end of a good long WOT pull and coast to a stop and then pull the plugs for a read. No off WOT running allowed.

In my experience, if you have clean burning gasoline, a clean brand new looking bone white insulator and NO sign of 1, 2, or 3 AND you see a nice mixture ring at the base, then you are making maximum power for the setup.


I used this method for two days, of as fast as she could go track days at last year's Shelby American Auto Club event at Las Vegas - several hours of 16 -18 pounds through a stock (except Stg2 cal and G valve) GLHS. Turned the boost up as I increased from 100% 91 octane California pissgass by adding racetrack gas until we were at 100% race gas. She ran great. Drove her home. Still going strong.

I know N/A plugs up, down, inside, out and sideways. Hence the post, something is not right... It may be between the seat and the pedal though.
I do have a "test" area near here that I'll be playing with tomorrow (now 1psi at a time over 10psi).
Plans for the fun stuff have changed between december and now so I seriously cannot blow this screwball up until at least July...(I like gas milage )

[BadAssPerformance]

50psi with the vaccum connected or disconnected? Should be good if it is with it disconnected, maybe turn up a pound or two.

Honestly if you didn't have any ping on those really freaking cold days a week or so ago, then you should be safe enough unless it gets colder out again, in which case, just run a little more fuel or less boost.

[mo' parts]

found this, i needed it on my new computer anyway.http://www.4secondsflat.com/plug_chart.html
http://www.4secondsflat.com/Spark_plug_reading.html

[Birddog]

50psi with the vaccum connected or disconnected? Should be good if it is with it disconnected, maybe turn up a pound or two.

Honestly if you didn't have any ping on those really freaking cold days a week or so ago, then you should be safe enough unless it gets colder out again, in which case, just run a little more fuel or less boost.

Disconnected, I bumped it to 55 though. I forgot about the weather. No ping and no pepper on the plugs though. I'd like to see a little more black than ash but I was beating on her pretty hard during that cold snap.

found this, i needed it on my new computer anyway.http://www.4secondsflat.com/plug_chart.html
http://www.4secondsflat.com/Spark_plug_reading.html

Cool site! Question though, Those are N/A plugs, wouldn't forced induction need to be read a little different?
(If I pulled these plugs from the wife's car I wouldn't have questioned them.)

[Tony Hanna]

I pulled plugs that looked considerably leaner than that out of the Daytona when I was running 28 psi and there was no evidence of detonation. I was spraying methanol at the time though.

[BadAssPerformance]

Disconnected, I bumped it to 55 though. I forgot about the weather. No ping and no pepper on the plugs though. I'd like to see a little more black than ash but I was beating on her pretty hard during that cold snap.

Not a terrible way to clean the valves off