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SBE gen iv LQ4, LJMS cam, T4 S475, TH350, 0411 ECU w/ HP Tuners
I started with Denmah's 2500 HD tune from the sloppy tune cabinet, and changed a few small things to work with my car (no trans etc). The car runs well enough, but when I get into boost, the timing falls off to 5 degrees until I get out of it. The timing will mirror the boost curve through a run.
My Cylinder air mass vs. RPM timing chart has a minimum of 13 degrees in the cells that I'm running in, so I thought it was an IAT or ECT related retard. I changed those tables to not affect timing until it saw temperatures that are well out of my operating range, and it still went to 5 degrees last night.
Is there another table that is affecting my timing? The car pulls well as it is, but I feel like I'm missing a lot of power, especially because I read where you lose ~25 hp/degree on these boosted LS motors. When I get home from work I can post my tune file, but here is a log from the track where you can see boost and timing.
You need to log ECT and IAT, as those are the 2 most likely culprits (there are a couple of tables that could be effecting this).
You should also change the MAP to read in kPa since that is how the tables are laid out and it makes it easier to reference from, might as well throw in cylinder airmass too.
In the table section, you can log various timing PIDs such as commanded timing, etc. Go ahead and insert any that seem relevant.
I have added those to my logs since this screen capture, just don't have a pic on my work computer. ECTs were 168 at start of run and 177 at end of run. My ECT table doesn't come into play at those temperatures. Driving around last night I made a few pulls and IATs stayed below 105, so I don't think that is affecting the timing either.
It looks like my minimum timing of 5 degrees is coming from that second table. What exactly is the "Enable cyl air delta" vs rpm table? I see someone elses tune has that all set to 0
I really appreciate the info and your tune, I'll look through it when I get home for lunch.
In my log posted above, I was monitoring Knock Retard, I figured that would spike if something was happening. But across all 8 runs, it never moved. Maybe I'm monitoring the wrong "Knock Retard" in VCM Scanner?
It's my understanding that burst knock pulls timing in anticipation of knock during large throttle position swings (starting line), for fuel economy mostly. Wouldn't it be OK to have it basically eliminated from a street/strip car that I don't care about fuel economy on hard pulls?
Since the previous track day I've switched to Denmah's log file that logs a lot more stuff. Next time I log something (hopefully tonight if it doesn't rain) I'll post a new screencap.
Here's 3 different test pulls tonight. On the 3rd run I forced the minimum timing to 9 degrees instead of 5. Other than that, I can't figure out what is pulling timing down so low... Any help would be greatly appreciated
I did. I used compare and changed my tables from the spark retard page to your values. I'll give the torque management a go next, I don't think I've looked at those tables in my tune. Thanks for your help Ron
I can't help with the current problem, I have no real tuning experience just trying to learn as much as I can, but was just curious it looks like your still running the MAF? Most people go to SD from what I seen, I would like to keep the MAF also just because I am climbing elevation in my normal drive everyday to work. What MAF are you running if you don't mind me asking?
Thank you
The MAF fails by default when it isn't hooked up, but I see it isn't failed in the tune.
I would set it to fail as shown below.
I assumed it was failed in the tune but didn't look........
Any chance I've turned off those codes? I seem to remember disabling or turning off some codes back in November. Maybe that's not even possible. I'll go throw those values in today just in case.
Ron is the man! Changed the torque reduction settings and turned off the MAF, voila 13 degrees timing and pulling HARD until it spun the ET Streets. I've been chasing this timing issue since we go the car running, thanks for all the help!
I was curious about the MAF, and thought you had one because of the CylAir (g) in the graph isn't that usually the MAF reading? thanks again I am just trying to learn before I start the build.
Thank you
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Timing gets pulled as soon as I build boost? 
