inconsistent timing problems durring 1/4 mile runs.

[TransAm-Z]

Does anyone know a good way to make timing consistent for WOT runs. I attached a log and current tune file...

My biggest issue currently is the timing drops 3 degrees in 3rd gear vs. 2nd gear at the same boost level. (19 deg in 2nd & 16 deg in 3rd At 204 kPa)

Can anyone explain to me what is causing this timing drop? As far as I know all of my torque management tables are zeroed out, & there is no knock retard in 3rd gear.

Ay help would be great.


Thanks,
Jeff

[BLK02WS6]

How do you know it is 204kpa, you are not logging Intake Manifold Absolute Pressure - SAE.MAP You have to log that for a Custom OS to read kpa...

But, the answer to your question is IAT - you go from 158F in 2nd to 189F in 3rd...

[TransAm-Z]

How do you know it is 204kpa, you are not logging Intake Manifold Absolute Pressure - SAE.MAP You have to log that for a Custom OS to read kpa...

But, the answer to your question is IAT - you go from 158F in 2nd to 189F in 3rd...

I see... Thank you very much I forgot about that table!

For some reason my SAE.MAP pid only logs up to 105 kPa, so I had to write a custom pid to calculate the the MAP pressure from GM.MAP (Voltage). I guess that makes it pretty hard for others to look at my log files...

[joecar]

If you're logging for tuning purpose, then limit the pid channel count to no more than 24 (see bottom of PIDs and Data tabs in scantool) for fastest sample rate.

[joecar]

Other comments:
- DYNAIR is pegging at 512 g/s (i.e. you have reach an internal limit),
- injector duty cycle is maxing out,
- 30° of ignition advance is too much advance,
- log SAE.MAP rather than GM.MAP (as BLK02WS6 said),
- be careful, the 1.00 EQR cells in B3647 will trim with STFT,
- HO/LO/Base spark tables have way too much advance [even for NA case] (note that when under boost pressure the air/fuel charge lights quicker),
- WOT downshift speeds are above the corresponding WOT upshift speeds (missed shifts),
- PT upshift/downshift curves are not very streetable,
- TCC is being applied in 2nd gear above 80% TP [kills single disc TCC] (not using the torque multiplying advantage of the stall).