Billiumss

iTrader: (11)

What do you guys use to see the "IAC" counts? Throttle %?

If you use HP Tuner 2.0, what PIDs should you use on a C5 to get the IAC table correct?

Phil99vette

iTrader: (11)

My memory is rusty...

Desired Idle Airflow
and
Dynamic Air
or
MAF

Use your ETC Area Scaler and modify the value to make the lines overlap.
Phil

Billiumss

iTrader: (11)

Any more on this, going to scan a C5 tomorrow to see how far his IAc tables are off.

Dixit

iTrader: (1)

Hey Phil, what do you mean by using the ETC Area Scaler to make the lines overlap. Better yet, what did you end up putting in that value for your 90mm TB? Im still highly confused on the whole ETC and tuning.

Dixit

Phil99vette

iTrader: (11)

basically the ETC scaler is a multiplier that will trigger your desired air flow vs actual(MAF or dynamic). do a log, adjust the scaler and you will see.
Phil

Dixit

iTrader: (1)

So you basically want to try to get the desired as close to actual airflow as possible by playing with the scaler? What value did you use for your 90mm TB?

HumpinSS

iTrader: (1)

B4349 = .0320

Dixit

iTrader: (1)

Cool, will give that a shot and use what Phil said about getting it close as possible

Bink

Dixit- Use value HumpinSS gave. Set the IAC park table to "Stock" values. Recalc your RAF table as the values will be less.

As the ETC scalar value increases the Desired idle airflow (g/sec) decreases - i.e. the "steps" of the throttle blade increase in size resulting in more actual airflow. More actual airflow results in a need for fewer steps (less TPS%) at idle. Fewer steps = Less Desired Idle Air. Hope this helps some.
FWIW.

Dixit

iTrader: (1)

Will that value still be the correct one when I install a ported 90mm TB?

Bink, excuse my ignorance, but Im slightly lost now. Isnt Desired Airflow what the PCM is commanding to get a good idle? Isnt that always going to remain the same no matter what value I put in there, or is there something Im missing.

I definetely understand the whole part of the fact that im going from the stock 78mm to 90mm TB means that the TB has to open up less than before because the same the amount of steps are still the same however because of the larger opening the same step will provide more air.

The part I dont understand is what Phil was talking about scanning and figuring out where you sit and adjust the scaler accordingly. What am I scanning to see how the scaler is correct or off and how am I doing this?

Thanks
Dixit

Bink

.0320 is for a 90 mm tb. I don't know if a ported 90 mm tb will change this. This should not be used for a 78 mm tb.

The Scalar value is the conversion constant. Basically it's defining the size of a single unit of blade rotation ( think of the "steps" of the IAC vale on an Fbod).
As you increase the value above .0255 (stock) the "desired airflow" values are less because they are scaled by the conversion constant. This is why your RAF values will also be less. Make sense??


Here's the info you need -> http://www.efilive.com/forum/viewtopic.php?t=1169

Dixit

iTrader: (1)

Right that makes sense, but did you understand the part Phil wrote about scanning to figure out what Scaler works best?

Dixit

Bink

Scan DESIAC and/or MAF and/or Dynamic Airflow. You should be able to get the MAF values to be nearly equal DESIAC. Dynamic Airflow will line up/coincide with DESIAC but (with a 90 mm tb) won't be equal. If the Eff Area Scalar is too great the LTIT and STIT will be erratic and unstable - I guess system is out of range due to the larger steps/% of the blade.