What parameters to datalog for a tuner?

[FastCougar]

Tom, this question is directed specifically to you. I know you have stated so in other threads, but I am creating this thread so that it can be stickied.

Exactly what parameters need to be datalogged in order for you to create a good baseline tune/rework an existing tune?

I'm just as guilty as anyone for forgetting a parameter or two, so please remind us. Better yet, to help educate everyone, a brief explination of each parameter would be helpful.

[warmonger]

Wow. I suppose it depends on who is tuning. Some people thing they are clairvoyant or something (with a car... :rolleyes: ) and some people claim they need everything. :evil:

-throttle position absolute
-rpm
-maf AD counts
-airflow in #/min
-load
-open loop flag
-imrc state (if imrc involved)
-Long term fuel trim bank 1
-long term fuel trim bank 2
-Short term fuel trim bank 1
-short term fuel trim bank 2
-O2 sensor bank 1 forward (or upstream)
-O2 sensor bank 2 upstream
-coolant temp
-intake charge temp
-spark timing
-knock sensor retard


This is probably the basic list and covers most requests. There will be specific requests if an issue is detected.

[gamiller]

There are probably over twenty parameters that are useful when troubleshooting the A/F mixture for a tune. Unfortunately, the XCAL2 only logs up to 15 at a time. These are the fifteen that Tom told me he needed most.

Environment
AIR_CHARGE_TEMP
COOLANT_TEMP

Fuel
STFT_BANK1
STFT_BANK2
LTFT_BANK1
LTFT_BANK2
OPEN_LOOP_FLAG

IMRC
IMRC_CMNDED_FLG

MAF
AIRFLOW_#/MIN
LOAD

Misc
RPM
TP_ABSOLUTE

O2
O2_B1_FRONT_V
O2_B2_FRONT_V

Spark
SPARK_ADVANCE

[michcougar]

Tom, this question is directed specifically to you. I know you have stated so in other threads, but I am creating this thread so that it can be stickied.

Exactly what parameters need to be datalogged in order for you to create a good baseline tune/rework an existing tune?

I'm just as guilty as anyone for forgetting a parameter or two, so please remind us. Better yet, to help educate everyone, a brief explination of each parameter would be helpful.

Awesome post!

Id like to find out where and what is causing me to run so rich. So a description of the parameter's would be great!