I've read some old threads and it seems like a lot of thinking has changes recently in regard to tuning the LS1. As far as idle, does it really matter what the iac's are as long as they aren't pegged? Also, if it seems like the rpms kinda fall slow between shifts, what parameter do i adjust? Would it be throttle cracker or iac decay? Or would this just mean i have the running airflow values to high? I'm just wondering b/c i was thinking i would adjust my throttle body set screw to lower my iac, but then I know i'll prob. have issues with the rpms hanging up and I need to know what to adjust when this happens. Sorry for the long post and thanks for your help.

 

If your iac counts are high, but you like the way it idles and it never surges or dies I would leave everything the way it is.

If your rpms fall slowly between shifts I would look at the iac decay first, but if they just kind of hang there forever as long as you stay at that speed I would start with the throttle cracker.

 

thanks