initial tuning of my 2010 LS3

[Malice]

Lew-

We spoke briefly via email, and I've started playing with my diablo, and the DSLOGREDUX software. I made this thread just to kinda "think out loud" about my tuning process. The car is a 2010 Camaro SS LS3. THe only mod is an aFe cold air intake. Later this spring I plan on getting Doug Thorley or JBA headers, but for now the stock exhaust will remain. Once I get the new exhaust, I'll be hitting you up for a pro tune. For now though, I want to familiarize myself with the software.

I followed the DSLOGREDUX instructions very closely. After putting ~50 miles on the freshly installed "DIABLO" tune, I made 2 65mph cruise logs in 5th gear at ~2300rpm. One was in the morning, at 47*F, and the other was in the afternoon, with a little less humidity and 68*F.

After running the two logs through the DSLOGREDUX, I got two recomendations for my injector slope. For the colder air, it wants me to decrease my injector slope by 14%. For the warmer air, it wants me to decrease them by 11%.

A decrease in fueling by over 10% seems a little aggressive and risky to me. I'm willing to try it, but I would like to see a second opinion before I do so. I don't want to lean out and burn up a new motor. Attached are the two logs. No one has to look at them, but here they are.

[2sscamaro]

Malice

By adding a cold air intake you would be "leaning" the afr by means of increasing the air flow.  Don't get caught up in a play on words with increasing and decreasing the slope.  By going 'Minus" on the slope you are richening. Positive numbers are "Lean" on the predator. If DSLogRedux is showing you need to go a -11, you are richening by eleven percent. I would try to get your LTFT's at -1.  Do not allow either bank  LTFT to stay at "0" if you are wanting to use DSLogREdux.  The "0" screws up the analysis.

[Malice]

So the ltfts are opposite too right? The ideal 0- (-)2 range means pinpointed to slightly rich?

[2sscamaro]

That's correct, when your cruise logs show a -1 to -2, you are slightly rich and where you need to be. As warmer weather arrives, due to the less dense and possibly more humid air, your trims will show you going slightly more rich (less available oxygen). But don't worry about that for now, just get the trims adjusted.  The predator will display and present the long term fuel trims in chunks of .7813 so if you can get them to settle (average) at -.7813 you'll be good to go.

[Malice]

After about 5 days of logging and tuning back and forth from work, I got my LTFT's in the 0-(-)2 range consistently. I went out today and played with the WOT aspect.

The fueling curve looks pretty good to me. If anything, it's a little rich. I took 3 WOT logs, and DSLOG redux says to reduce my PE by -1% to -3% in the high rpm band depending on the log. I'm hesitant to do that because of the KR I'm getting. If anything, it seems as though I'll need to richen up my high RPM band fueling to get rid of the KR.

Furthermore, I'm amazed at how low the ignition timing is, even with the diablo tune installed. I'm looking at an average spark advance of 18-20*. Old SBC's ran like 33*+ timing, and my 99 camaro V6 ran ~28* at WOT. Does the LS3 run such low timing because of the high compression?