WOT Timing always 2-3 degrees low

[MikeGyver]

2-Bar SD tune. I'm asking for 17 degrees. At full throttle, it goes to 14 degrees and flat-lines until I start losing fuel pressure and get KR. That I'll address later when the new pump gets here. For now I want to get control over the spark.
I'll try to give you as much as I can, I'm sure it will all be no help, because if I knew where to look I could probably fix it.
2000 GMC 2500, 408, S/C, intercooled, heads, headers, blah, blah, blah.
The motor was just upsized, all new guts. At WOT the boost hangs between 165 and 175 kPa. I have the high and low octane tables the same. AFR spark correction table zeroed out. IAT is between 60 and 70 degrees during run, keeping the spark in the zero part of that table. ECT steady at 175, again zero spark correction. EGR disabled, table zeroed. Traction control aggressive zero. Max. torque tables all 640. Spark retard vs. torque reduction, zero.
What's next?
Thanks, Mike.

[EC_Tune]

How about burst KR. If your dynamic airflow moves around too much at WOT it can pull timing if the delta Dynamic Airflow trips the burst knock threshold.

[MikeGyver]

The kPa line is very wiggly, it looks kind of like an alternating current wave, kind of steadily going from 165 to 175, in an irregular fashion, if that make sense. That said, after I start logging burst knock and find out that that is where my timing is going, do I really want to change it?

[MikeGyver]

I just realized- does the graph look like that because i have the MAP sensor getting its signal from the vacuum port on the intake runner on a Vic Jr. instead of a more central location? It seems like that cylinders intake valve should be cycling way faster than my kPa graph is wiggling, though. Just a thought.

[Bill@HPTuners]

need your .hpt & .hpl files.

[EC_Tune]

Runner isn't the *ideal* place if you have a choice. Under boost it shouldn't matter as much though.

[John_D.]

You can get some map wiggle if your wastegate is cycling to manage the boost level.

Sounds like you hit the main tables that tweak the spark.
Probably will have to log all the spark related pids and start narrowing it down that way.

[MikeGyver]

need your .hpt & .hpl files.

I've never posted a tune or a log because of embarrassment. The state of tune is mostly due to laziness, and anything that is wrong is my fault, not the mail-order tuner that I bought it from. And sorry the log is so long.

[EC_Tune]

One thing I noticed: If you have the Mototron 60's then your IFR table is wrong. Also, it looks like your fuel pump needs help. It's dropping at least 10 PSI from it's max value in boost.

[MikeGyver]

Yeah, the new pump should be in this weekend. I don't know what brand the injectors are. At this point, how would I benefit from rescaling the IFR table?

[MikeGyver]

Since I am going to have to change the VE table after I get even fuel pressure across the board, I'll go ahead and change the IFR table, if I knew what to change it to. Will I have to pull out an injector to find out what brand it is? Anybody on the spark yet? And also, my tuner told me to set up my fuel pressure regulator (MagnaFuel) for an even 59 psi at all kPa. Is that because of the IFR table he gave me? Or visa-versa?

[EC_Tune]

If you have a boost referenced fuel pressure regulator (and it looks like you do from your fuel pressure readings) the IFR should be flat.

If you have the Mototrons (says Mototron on the side near the Siemens P/N) IFR should be 70# across the board.

[MikeGyver]

It was burst knock, I finally logged it instead of just talking about it. I zeroed the table out above 2000 rpm, I still get a lot of KR in the below 2000 range. Sorry that I didn't listen in the first place.

[EC_Tune]

No prob. At least you know that you know. Some think they know but don't know. Some act like they know and do know. Some don't have a clue that they don't know. You're in the know.