In my .bin I have a table called IAT/CTS blend filter.
The table has two columns one is listed GmSec the other %ofC.

I'm trying to understand and I hope I have this right
GmSec is equaling the outside air temp somehow and applying it to a percentage of the coolant temp? Heck, after typing it,it makes no sense to me.. I need a "tuning for dummies" book.

I'm trying to fix a problem where my motor runs richer during the summer (11.5 idle, 15.5 cruise) then in the fall when the outside air temp comes down the AFR is 12.1 at idle and 14.5-15.5 cruise

 

What year computer are you using? I would like to look at the table before I offer a response on what it does.

 

I remember starting this: http://www.thirdgen.org/techboard/di...nt-bias-q.html

This is what RBob posted in above thread:

(quote)The CTS/IAT Blend table is the percent of CTS used. So a larger value is toward more CTS compensation vs IAT.

At higher airflow the table has lower values for less CTS% in the blend. The remaining % of the blend will be IAT contribution.

As an example, if the table has a 75% value in it. That means the blended CTS/IAT temperature will be 75% of the CTS and 25% of the IAT.

Then with the CTS at 200* F, and the IAT at 72* F, the CTS/IAT blended temperature will be:

200 * 0.75 + 72 * 0.25 = 168* F

RBob. (end quote)

So what I think what RBob is saying is that those tables account for higher air flow as well as differential between temps at Ac vs temps of coolant at intake.

Cool temps at AC and high flow it will add much more fuel than warm temps at AC and low flow numbers(gram/sec).

I dont have TP here at office or I would look at "my" values. I would think I would need to look at flow #'s in datalog as well.

I believe an accurrate table(s) will keep BLM at 128 regardless of IAT temps or coolant temps. Again one needs to look at logs to see what is happening so as to know what to tweek in tables....

Another item I need to look at next tuning season. Other being calibrate my BPC vs VAC with a Mighty Vac....

 

Here's a screen shot of what I'm looking at.
I can read and read but I'm just not putting together how GmSec is equalling air temp then applying it to the percentage of coolant

 

I am struggling with this as well and would like to calibrate it come spring. All I can come up with today is you need to find a baseline like 98dF coolant temp(100% per table in tread linked to) and correct the VE so as to achieve your BLM of 128. Granted it would need to be dam near perfect BLM for all RPM/MAP. Knowing that and using the table of air density shown in that post you need to look at your datalogs of grams/sec. 160 grams per sec is 13.73% in "your" table for coolant bias. If you are running BLM of 122 at 160 grams or say 134 you need to add or subtract from that table. 134 lean adding fuel you might increase the bias adding fuel by decreasing 13.73 by 4.7% expecting the BLM to improve to 128? You would then need to look at BLM for all grams/sec and adjust accordingly. My best guess.

Edit: The more I think of it the more I say leave it alone. there are some variables that may not be a variable. coolant temop is the same for my car as yours. So would be the inlet air being monitored for temp. air density is same as well. Air is air. So those three factors all the same. Only difference may be the IAT itself. But GM-Delco are most like all the same slightly differing part #'s. Motorcraft may be same as well. GM may have calibrated that table for us perfectly. Only thing I can see that changes would be if the inlet tract is longer or shorter car to car? Possibly not significant.