Anyone here know about the A/C tables?
Apr 21, 2012 | 08:58 PM
#1
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TECH Senior Member
iTrader: (5)
Joined: Dec 2010
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From: Las Vegas, NV
Anyone here know about the A/C tables?
Well boys, it hit 100 degrees here today in Las Vegas. So I guess that means it's summer time. I tried getting a response over on HPT forum about the A/C tables and how each table effects A/C operation. No answer so far. I did some searching on HPT and google but couldn't come up with any info. So I will bring it up here and see if anyone is knowledgable in this area. Below is my post on HPT:
Can someone explain the different tables that control the air conditions system in the pcm. Inertia tq, ramp in/out, spark retard, ect. This might be a stupid question but I'm having a hard time understanding what these tables tell the pcm to do.
Is the inertia tq table something that tells the pcm how much tq the a/c clutch will take to engage? So if your rpm drops when engaging, the numbers in the inertia tables should be increased?
I don't understand what ramp in/out is at all.
Why would the pcm want to retard spark advance when the clutch engages? Thanks guys
Can someone explain the different tables that control the air conditions system in the pcm. Inertia tq, ramp in/out, spark retard, ect. This might be a stupid question but I'm having a hard time understanding what these tables tell the pcm to do.
Is the inertia tq table something that tells the pcm how much tq the a/c clutch will take to engage? So if your rpm drops when engaging, the numbers in the inertia tables should be increased?
I don't understand what ramp in/out is at all.
Why would the pcm want to retard spark advance when the clutch engages? Thanks guys
Apr 21, 2012 | 09:36 PM
#3
The spark ones pull timing when the clutch engages...
The Torque loss helps with airflow. It adds addition air flow when the AC clutch is engaged.. Basically it adds on top of your Desired Airflow/Running Airflow. The way you set it is, dial in our Desired Airflow like normal with the AC off, then after you have it dialed in you can do 1 of 2 things... turn on your ac and log your desired airflow again, note the difference, then multiply the AC TQ loss or AC TQ Loss IAT table by that percentage, or what i did was just multiply the AC TQ Loss IAT by 10%, then drove it, it still surged so i added another 10%, and drove it, basically i repeated this process 5 times increasing that table ~50%.
The Torque loss helps with airflow. It adds addition air flow when the AC clutch is engaged.. Basically it adds on top of your Desired Airflow/Running Airflow. The way you set it is, dial in our Desired Airflow like normal with the AC off, then after you have it dialed in you can do 1 of 2 things... turn on your ac and log your desired airflow again, note the difference, then multiply the AC TQ loss or AC TQ Loss IAT table by that percentage, or what i did was just multiply the AC TQ Loss IAT by 10%, then drove it, it still surged so i added another 10%, and drove it, basically i repeated this process 5 times increasing that table ~50%.
Apr 22, 2012 | 10:51 AM
#5
How does the PCM control idle in steps? (1st, 2nd, 3rd, 4th)
If the first thing that the PCM does to correct idle is increase or decrease timing because it can dp this quicker than moving the IAC on a DBC then why would it retard the timing when the AC kicks on?
If the first thing that the PCM does to correct idle is increase or decrease timing because it can dp this quicker than moving the IAC on a DBC then why would it retard the timing when the AC kicks on?
Apr 22, 2012 | 10:37 PM
#6
Thread Starter
TECH Senior Member
iTrader: (5)
Joined: Dec 2010
Posts: 5,235
Likes: 4
From: Las Vegas, NV
How does the PCM control idle in steps? (1st, 2nd, 3rd, 4th)
If the first thing that the PCM does to correct idle is increase or decrease timing because it can dp this quicker than moving the IAC on a DBC then why would it retard the timing when the AC kicks on?
If the first thing that the PCM does to correct idle is increase or decrease timing because it can dp this quicker than moving the IAC on a DBC then why would it retard the timing when the AC kicks on?
Apr 22, 2012 | 10:51 PM
#7
Thread Starter
TECH Senior Member
iTrader: (5)
Joined: Dec 2010
Posts: 5,235
Likes: 4
From: Las Vegas, NV
The spark ones pull timing when the clutch engages...
The Torque loss helps with airflow. It adds addition air flow when the AC clutch is engaged.. Basically it adds on top of your Desired Airflow/Running Airflow. The way you set it is, dial in our Desired Airflow like normal with the AC off, then after you have it dialed in you can do 1 of 2 things... turn on your ac and log your desired airflow again, note the difference, then multiply the AC TQ loss or AC TQ Loss IAT table by that percentage, or what i did was just multiply the AC TQ Loss IAT by 10%, then drove it, it still surged so i added another 10%, and drove it, basically i repeated this process 5 times increasing that table ~50%.
The Torque loss helps with airflow. It adds addition air flow when the AC clutch is engaged.. Basically it adds on top of your Desired Airflow/Running Airflow. The way you set it is, dial in our Desired Airflow like normal with the AC off, then after you have it dialed in you can do 1 of 2 things... turn on your ac and log your desired airflow again, note the difference, then multiply the AC TQ loss or AC TQ Loss IAT table by that percentage, or what i did was just multiply the AC TQ Loss IAT by 10%, then drove it, it still surged so i added another 10%, and drove it, basically i repeated this process 5 times increasing that table ~50%.
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