SideStep

I have been logging my Mass Air Flow (lb/min) and Idle Desired Air (lb/min) since I installed my FAST 90 and ported LS2-TB. My Idle Desired Air is always .2 - .24 lower than my Mass Air Flow.

I have not messed with these settings but I take it I need to raise my ETC Area Scalar by the percentage difference???


Here is a JPG of the histogram

HumpinSS

iTrader: (1)

I am not to sure about the DBW stuff but i know on the FBodys there is no reason to touch it if you are running the "SAME" IAC motor

SideStep

I read somewhere here that the IAC settings do not affect DBW vehicles (C5s). Most with 90/90 setups set there ETC Area Scalar to .0320, but I would rather have an exact method of determining how much OR if I need to adjust the scalar. After reviewing my idle logs it looks like I need to increase my scalar from .0255 to .0317 (very close to .0320).

I hate playing dumb on this but what exactly were/are people hoping to cure buy making these changes???... more accurate idle fueling???

HumpinSS

iTrader: (1)

When iI changed mine i was the latest fad on this forum but i quickly found out it caused more problems than it was thought to cure

slow

iTrader: (7)

do drive by wire vehicles even have a iac motor?

Ryan

HumpinSS

iTrader: (1)

Nope the whole TB is used for that. This is the reason you wont see 0% TP on a DBW vehicle

slow

iTrader: (7)

ok, that's what I thought....

ETC is normally used since it is cheaper, no iac motor needed, no throttle cable, and no cruise control module needed.

Ryan

Phil99vette

iTrader: (11)

Try different numbers and you will find some very interesting things that happen when it comes to counting airflow.
Phil

Bink

Check your LTITs and STITs. If they're reasonable I would leave it at 0.0255.

My NW 90mm TB works best at .0320 (2001 C5) - but that has to do with how the TB was setup by Nick Williams. Mine was a very early TB setup by Nick. Later TBs were setup to work with the .0255/stock value.

FWIW.