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Will someone please explain how to tune the A/C. When I turn the A/C on in my truck, the extra load on the motor makes it drop almost 500 rpms. How do I compensate for the extra load and how do I make the clutch cycle? Thanks
Truck is a 2003 Silverado
408 LQ4
LS3 heads and intake
231/239 114+2
Anyone?
Build your self a config, leave rpm and map and maf if you are running it, delete everything else. Go to idle section and add all available pids. When you turn on ac, you will see how much air is being added to compensate. Yours is not adding enough, so you will see idle trims compensate. When you see how much total air is being added, go to the adaptive idle section under idle-airflow and change the value to the proper airflow.
there is also a TQ table for when the ac is on. it under tq management
do you happen to have any data on how to log data to correlate that to how to adjust those tables? I understand that is functionally the first place the engine makes the changes for AC running and then from there it goes to the adaptive idle airflow to adjust if that isn't close enough.Quote:
Originally Posted by detroit
I believe there is an "initial adder" table for A/C that we do not have access to. I'm battling this right now on my Formula, idle's like a champ when it's off with LTIT and STIT all reading 0 even when fans come on and off still no blurp in STIT... as soon as the A/C comes on it adds between 1.5-2.5 g/sec of A/C airflow and STIT add another 1-1.5 g/sec. No matter what I change related to A/C airflow in our editor nothing changes that A/C airflow value. I've been trying to get to the bottom of it and seems there is an A/C idle airflow adder table that just isn't in our editor... I may be wrong but I've seen this table in other brands suite's.
I had the same question...so I exported the stock table to excel and made a graph. Then I inserted a trend line (think it was a 2nd degree poly, looks like a s) then I could see that in the running temp area I needed to add and at higher temps it could be lowered to more closely resemble the trendline. I then added 10% to the cells that needed 'more'. It has helped but I still got issues when the temp shot up recently.
When I moded this table, the other TQ load table changed. I thought this was interesting, but it seemed like it followed logic. The other table can be used to adjust for other accesory torque...never thought about how it might be used with a blower?? backontopic
So what do I need to change in the A/C torque tables. Do I add 10% to the tm tables until it doesn't drop rpm?
yea, kind of :)
I added 10% to my table where I am operating at, it was like five cells.
YOu can watch your idle trims and see if they are moving in the right direction with your changes
What tables do play with?
engine>torque management>engine>ac compressor TQ vs IAT
the other one is on the same tab but >accesory torque
Okay thanks guys, I will play and see what happens.
Still having problems with ac.... It's frustrating as hell. No one seems to know what each ac table does under tq management.
My converter is really loose and I when i take off from a stop sign, I can always feel the ac clutch engaging about a 1/4 of the way through first gear. It feels like it puts a ton of strain on the motor. I just can't figure out what tables to add airflow to to compensate the extra load.
I was able to add air for the AC using the Proportional Idle Table.
I added a lot from the 0 to 250 rpm in the "low" table and zeroed the "high" table.
i found what works is to add more raf than you need, by roughly 5% so the ltit and stit are always negative, when the a/c engages it will go back to zero or close to it and wont drop.
I went ahead and copied the stock ac tables from a 2004 z06 and it runs a ton better. Silverados only use the IAT table for added airflow where the Z06 uses ac pressure and IAT.