White spark plugs, high 02s now I am confused

[boostineklipz]

Alright, after a couple days of trying to fine tune the big 16g, I decided to take a look at the spark plugs. They were a greyish white, but more white then grey. So it appears I am running lean. What I dont understand is what the pocketlogger is showing me in 3rd gear:

3864 RPMS
11 degrees- timing
o2-.94v

4574 RPMS
7 degrees- timing
02-.96v

4928 RPMS
19 degrees- timing
o2- .96v

5460 RPMS
13 degrees- timing
O2- .98v

5860 RPMS
22 degrees of timing
02- .98v

I know 15-16 degrees of timing is optimal for a 2g. What the hell is going on here, am I running rich or lean. The pocketlogger leads me to believe I am running rich but the spark plugs show something different. The S-AFC is set to around -17-18 for high settings with 550s and a walbro 190.

 

[steve]

Two things, whitish plugs don't always mean too lean and O2 voltages are not absolute. That said, If those numbers are from the same run at WOT, I wonder if you not seeing some knock causing those drops in timing at 4500 and 5400.

Steve

 

[Defiant]

Except in extreme circumstances, plug readings are pretty much a thing of the past. Even in that past, they were often useless- you can seldom do a decent plug cut because engines don't just "shut off" when the ignition is turned off. They keep spinning from flywheel and crankshaft inertia, drawing in mixture and inevitably firing from compression heat. Fuel injected, closed-loop emissions systems can make it worse, because while you're trying to make adjustments, it's trying to compensate.

 

[Mike 99GSX]

15-16 is not optimum for a 2g. More like 19-20 degrees. o2 values are almost useless for the pocketlogger and somewhite white plug tips are also normal on our cars. You should hopefully see about 20 degrees timing at the top of 3rd gear with a gradual increase to that point from when your turbo hits full spool up.

 

[nine5raptor]

15-16 is pretty good for stock injectors or for people maxxing out larger ones. I would be happy as hell to be able to get 16 running a decent amount of boost.

 

[kpt4321]

That big dip in timing makes me think you have knock.

 

[44pirate]

With 550's you should be at least at -20 to start with on the Hi settings. YOur running rich. Getting knock from rich condition.

 

[boostineklipz]

Originally posted by Mike 99GSX
15-16 is not optimum for a 2g. More like 19-20 degrees. o2 values are almost useless for the pocketlogger and somewhite white plug tips are also normal on our cars. You should hopefully see about 20 degrees timing at the top of 3rd gear with a gradual increase to that point from when your turbo hits full spool up.

really, I always thought it was 15-16 from what I read. Thanks for the good info.

 

[Mike 99GSX]

Where is your turbo getting full boost at? The dip at 4500 would be OK if thats where you were getting full boost at but that would be really bad for a 16g. If its like 3500 like a 16g should be, then Kyle T is right and you are knocking there. It does seem though that the 2gs are suseptable to a timing dip in that RPM range. I had a similar problem with my 16g and others have reported it as well. It would be helpful if you could post another graph of a 3rd gear pull with more RPM points.

 

[boostineklipz]

Here is one from tonight, the air temp was a little high (93-96 degrres) but here is what I got:

3104 RPMS
16 degrees- timing
o2-.36v

3664 RPMS
11 degrees- timing
02-.94v

4136 RPMS
7 degrees- timing
o2- .94v

4576 RPMS
9 degrees- timing
O2- .94v

4972 RPMS
8 degrees of timing
02- .96v

5228 RPMS
17 degrees- timing
o2- .74v

5720 RPMS
13 degrees- timing
O2- .96v

6056 RPMS
14 degrees of timing
02- .96v

I am assuming timing is getting pulled cause of it running too rich? Boost also doesnt seem to kick in at 3500 rpms, its def later then that.

 

[1fast97gsx]

Originally posted by Mike 99GSX
Where is your turbo getting full boost at? The dip at 4500 would be OK if thats where you were getting full boost at but that would be really bad for a 16g. If its like 3500 like a 16g should be, then Kyle T is right and you are knocking there. It does seem though that the 2gs are suseptable to a timing dip in that RPM range. I had a similar problem with my 16g and others have reported it as well. It would be helpful if you could post another graph of a 3rd gear pull with more RPM points.

Thats exactly how mine looks too with a 16g ( ported ) at 1.20 bar. Of course I am running stock injectors and only 1.15 bar and then my timing ends up aound 16 degrees. Maybe lower the boost a tad?

 

[kpt4321]

Rich knock is a myth.

 

[98TsiAWD]

It looks to me that from 4-5k you are getting knock retard. What are you tuning with? Can you pull timing with it?

 

[MNGSX]

I would'nt get too worked up about it.

Do those pipes for that spearco you have and intstall it. Something tells me that cooling air coming out a larger IC will help you alot.

 

[Mike 99GSX]

I don't think you have rich knock either. First thing though is why are you getting boost on a 16g until over 4000 rpm? Have you check for any boost leeks? If you have a bad leek it will screw things up. The 17degrees thing at 5200 is also weird. Are you sure you didn't lift off the throttle a little there? Everything else isn't that bad. The low timing is probably where your turbo is hitting full boost so thats normal. You probably would have had close to 17 degrees advance if you would have taken it all the way to redline.

 

[boostineklipz]

Originally posted by 98TsiAWD
It looks to me that from 4-5k you are getting knock retard. What are you tuning with? Can you pull timing with it?

S-AFC

I don't think you have rich knock either. First thing though is why are you getting boost on a 16g until over 4000 rpm?

Its clipped, but I would think it would spool faster then that. I will check for boost leaks later today.

I would'nt get too worked up about it.

Do those pipes for that spearco you have and intstall it. Something tells me that cooling air coming out a larger IC will help you alot.

Do you think it could be a cooling problem? These logs were at 15 psi on the stock side mount IC.

 

[MNGSX]

A cooler AF mix will tolerate more advance without detonation.

So yes.

The factory SMIC could be heat soaking on you.