A/C tuning, Gen 3 P01
Thread Starter
Joined: Apr 2007
Posts: 9,711
Likes: 999
From: Evansville,IN
A/C tuning, Gen 3 P01 To preface this, I did search about this question, but never found an actual answer or process how to do it. I did find one good video on YT where Evans Performance Academy where they talk about it. But I'm guessing they used it as a teaser to buy their training.
Since I bitch about it, I should tell you what I'm working on.
2000 Firehawk, turbo blah blah, cam has a **** ton of overlap.
P01 PCM
I've spent A LOT of time tuning this thing and i'm really happy with it. Now that it's hot as *****, I need my AC.
My BRAF table is pretty solid, my STIT are normally +/- .5 g/s.
When I turn the A/C on, I can see it adding a bunch of A/C idle air, somewhere between 3-4 g/s.
How is that calculated? I have all my idle adapatives zero'd out.
I know about the the ENGINE>TORQUE MODEL>LOSS>A/C vs pressure table, but don't understand it.
I understand it's supposed to be frictional loss, but how is it calculated and where does the A/C idle airflow value come from?
More importantly, what do I need to log to know how to change it correctly? That's the point in the process where the YT video stopped.
I appreciate any help.
Since I bitch about it, I should tell you what I'm working on.
2000 Firehawk, turbo blah blah, cam has a **** ton of overlap.
P01 PCM
I've spent A LOT of time tuning this thing and i'm really happy with it. Now that it's hot as *****, I need my AC.
My BRAF table is pretty solid, my STIT are normally +/- .5 g/s.
When I turn the A/C on, I can see it adding a bunch of A/C idle air, somewhere between 3-4 g/s.
How is that calculated? I have all my idle adapatives zero'd out.
I know about the the ENGINE>TORQUE MODEL>LOSS>A/C vs pressure table, but don't understand it.
I understand it's supposed to be frictional loss, but how is it calculated and where does the A/C idle airflow value come from?
More importantly, what do I need to log to know how to change it correctly? That's the point in the process where the YT video stopped.
I appreciate any help.
Last edited by LilJayV10; Jun 22, 2024 at 08:20 PM.
On The Tree
Joined: Mar 2010
Posts: 124
Likes: 8
From: Navarre, FL
In this case it takes torque and converts to airflow. That table is required torque vs AC pressure.. I needed to add more AC idle airflow, so I bumped this table, the IAT one, and Torque Model -> Engine -> AC torque one all up by 10 percent or so to get started.
It's all the same as AC off, just another AC idle airflow adder that's part of the equation. If AC off is working great and now with AC on it's struggling, or idle is dipping after a rev, I try to touch only the AC specific tables so I don't mess up the AC off operation.
If if's still struggling you can increase idle RPM for AC on only, and "stall saver" might not be a bad thing to turn on, if not already and it's stalling out. It will kick in more airflow aggressively if idle droops and turn off the AC compressor for a moment to save it.
It's all the same as AC off, just another AC idle airflow adder that's part of the equation. If AC off is working great and now with AC on it's struggling, or idle is dipping after a rev, I try to touch only the AC specific tables so I don't mess up the AC off operation.
If if's still struggling you can increase idle RPM for AC on only, and "stall saver" might not be a bad thing to turn on, if not already and it's stalling out. It will kick in more airflow aggressively if idle droops and turn off the AC compressor for a moment to save it.
Thread Starter
Joined: Apr 2007
Posts: 9,711
Likes: 999
From: Evansville,IN
I appreciate the reply.
I figured it had to be using torque based off airflow, which I am guessing is based off fuel flow.
Right now it's adding about 2 g/s when driving, when I push the clutch in, the RPM's hang really high, like the cracker table is wrong. With the A/C off, the car drives fantastic.
I was going to mess with tuning the A/C on Sunday, but I did 3-6.8k pull in 4th gear Saturday night, P/S pump started leaking and killed my brand new Powermaster alternator. First time the car has come home on a roll back.
I figured it had to be using torque based off airflow, which I am guessing is based off fuel flow.
Right now it's adding about 2 g/s when driving, when I push the clutch in, the RPM's hang really high, like the cracker table is wrong. With the A/C off, the car drives fantastic.
I was going to mess with tuning the A/C on Sunday, but I did 3-6.8k pull in 4th gear Saturday night, P/S pump started leaking and killed my brand new Powermaster alternator. First time the car has come home on a roll back.
Thread Starter
Joined: Apr 2007
Posts: 9,711
Likes: 999
From: Evansville,IN
I found this searching this morning. So far, it's the best post I've seen explaining it. A/C stuff is in post #2.
It's hotter than ***** today and I'll be seeing what I can figure out.
https://forum.hptuners.com/showthrea...compressor+iat
It's hotter than ***** today and I'll be seeing what I can figure out.
https://forum.hptuners.com/showthrea...compressor+iat
On The Tree
Joined: Mar 2010
Posts: 124
Likes: 8
From: Navarre, FL
I had a add a decent amount of AC airflow on mine to avoid rev dip when returning to idle. In addition to the torque tables, which translate into AC idle airflow adders, you can also just change the Min AC LTFT value to like 0.5 g or something like that and avoid the guess and check of adding X amount of torque to see how much Y airflow gets added as a result. I ended up adding a little both ways to get desired end result.
