MAF Signal

[Spindoctor]

Hi all!:wave:
Since I am new to GM format tuning (see my signature below) I have a question concerning the MAF output of this 06 LS2.
When looking over logging files after a run the MAF raw signal (and other directly associated PID sigs) do not rise linearly with the RPM. They tend to rise and fall erratically. Is this a normal characteristic of the GM MAF? (resonant manifold sensitivity?)
I am a BMW\Benz tech by day and any sig like this would get the MAF a trip to the dumpster.
What I am trying to isolate on the particular engine is a constant Knock timing retard of about 2-3' from 2500 through 5500 at WOT.
Could be our poor winter gas.
Car runs great 330rwhp and 351rwtq. @12.25:1 afr. I think it could be better
but not with KR happening.
And whats up with the 82% max thrtl. Is that GM for WOT or do I have an issue?

Also- Customer is complaining of the delay during paddle shifting. I agree it is SLOOW. Ferrari's will shift before you can lift off the paddle.
He is a very competitive driver locally and this is his biggest issue.
Is there anything I can adjust to make this shift faster\firmer?

I promise to return info to the forum once I have learned a thing or two or five!

[hymey]

Hi Spin,

The knock sensors are very sensitive in these engines and I wouldn't rely on them for accurate data. I have heard these engines knock and the knock sensors didn't pick it up but on the other hand it has picked up false knock on numerous occasions. Turn KR off and run the car on the dyno. Listen for knock adjust timing accordingly and then enable the KR function and keep a close eye on it. You can adjust the KR settings.

Cheers

Joel

[GMPX]

What I am trying to isolate on the particular engine is a constant Knock timing retard of about 2-3' from 2500 through 5500 at WOT.
Could be our poor winter gas.

What sort of timing is it trying to get at WOT?, pull 5 degrees out and see if the knock goes away, look at the tailpipe, it is puffing black smoke?


And whats up with the 82% max thrtl. Is that GM for WOT or do I have an issue?.
It's a GM thing.


Also- Customer is complaining of the delay during paddle shifting. I agree it is SLOOW. Ferrari's will shift before you can lift off the paddle.
Ferraris cost more that's why ;)
Paddle delay is an on-going issue, but the box can be made to shift a little faster and firmer. Many just disable all the torque managment in the TCM and drop the desired shift times down.

Welcome to the world of late model GM tuning!, these ECM's are pretty powerful so it will probably take some getting used to.

Cheers,
Ross

[ScarabEpic22]

Hmm, Kirkland, WA huh? And you have an AWD dyno...hmmm. Need to get a baseline for my TB before I s/c it this summer...