ls1 tune

[gregw1]

Hi having problem with fuel mixture at wot mixture is different depending what gear I am in at the same rpm cant work out why. Car is 5.7 ls1 218 224 @50 550 lift otr cold air intake 2.5 inch exhaust 2004 Monaro Thanks Greg

[nkautz]

Looks like that's from IATs dropping during the pull. You started at 108* and ended at 90*. That's a 20* change throughout the pull. The stock cylinder charge bias table values are what causes this. GM put this table in to help automatically reduce fuel when the intake air is hotter and less dense, but I think they got their formula wrong, it overcompensates and leans out too much. The way you can help correct it is by either spending hours playing with the bias table and re-tuning with each change, or you can set the bias table to all 1's , which is where I landed after spending hours playing with it. You need to re-tune maf/ve but once you're done , the issue you are having will be much less. It also helps alot for heatsoaked starts where sometimes the afr would otherwise be in the 17 and 18 range. The only downside that I've seen is that cold starts will be richer.