Michael Ozorowsky

iTrader: (1)

Hey, any write-ups out there for tuning when ac is on? Or is there no special tuning needed? Thanks in advance.

30thta436

iTrader: (10)

I replied to your post on Hptuners.com

Michael Ozorowsky

iTrader: (1)

No one seems to be reading HP Tuners. What can I do to properly tune idle with AC ON? Can anyone help? Please.

P Mack

iTrader: (6)

I think i changed my stit, ltit, and ac airflow adder limits all to 3.0 g/s (i'm going from memory here since my laptop crashed). Also you may want to enable stall saver because that will disengage the ac clutch if your rpm drops below a certain point. Oh yeah, I also made my ac idle speed 850 with my normal idle speed at 800. Besides that, i think if you make sure all the normal stuff is good you should be set.

C5XP

iTrader: (5)

Get your ltit right with a/c off. Then when you turn on your a/c see what the a/c airflow is and what the stit's jump to. You will probably need more a/c airflow. With moderate to big cams you usually will see about 2-4 on a/c air flow, but the stits will rise high trying to add enough airflow. If this is the case you need to add more a/c airflow.

Michael Ozorowsky

iTrader: (1)

Would someone be willing to look at a log of mine? I can do fresh log tomorrow. I will start car, log, and let sit there until it gets to operating temp.

From what I have noticed for some reason, is I log my idle while driving is that bad?

I notice my Ltit, to be -.08 all the way through, then after car warms up and gets hot it jumps to -.32 or something crazy. Doesn't make sense to me. That is with AC off.

With ac on, my Ltit/Stit goes to zero, and there is something in hp tuners called a/c airflow or something like that. If someone could get me on track would be very much appreciated.

GuitsBoy

iTrader: (4)

So basicly, the ECU keeps track on how much air to add when the a/c compressor engages? This is limited to .5 in the stock tune? In reality cammed cars may see a much bigger spread between a/c-off and a/c-on airflow. If you have perfect idle trims and you turn on the a/c and lets say it requires .75 additional air, once the a/c trim reaches it's max difference ( .5 ) it starts to adjust the stit to the remaining.25. Then when you turn the a/c off, your stit is still at .25? So the a/c additional airflow limit ( .5 ) needs to be upped?

30thta436

iTrader: (10)

yes and no. You are talking about your adaptive idle learn limits. A/c adaptive idle learn is limited to -.5 to .5. This is the max learned adjustment to the base a/c airflow. This means if your base a/c idle airflow is 2.5 and your stits with the a/c on is 2, then when you turn the a/c off and back on the base airflow will be 3.0. I'm not 100% on this and probably not describing it correctly.

You have a pid for a/c airflow. You need to get your LTIT in check with the a/c off. Then turn on the a/c. You will see an a/c airflow amount on the a/c airflow pid. It is somewere around 2-3 stock. When you put in a moderate to big cam, this is not enough airflow. You need to tune it like you do the LTIT's. With the a/c on look at what the stit's do. If they go way positve, then you don't have enough a/c airflow.. This is just like stit's and ltit's. you add airflow until the ltit's and stit's get around 0. I actually like them a little negative (better to more airflow then not enough). Except with the a/c airflow you only use the stit's to see what adjustment you need to make to the a/c airflow.

30thta436

iTrader: (10)

if your LTIT's are 0 to -1.0 then you are ok. When you turn on the a/c you will see an airflow amount show up on the a/c airflow pid. This is the base a/c airflow. shortly after that you should see the STIT's start to move (probably positive). If STIT's go positive then you need to add a/c airflow. If the STIT's go negative then you need subtract a/c airflow.

Michael Ozorowsky

iTrader: (1)

let me see if I got this straight: What I do is start scanning STIT/LTIT. Look at LTIT, let's say is -.08, then (with hp tuners) I go to my base running air flow, and -.08 from whatever temps necessary. Then, I turn a/c on, and look at my STIT, what table do I modify? Could someone please explain this as easily as possible?

RedHardSupra

iTrader: (1)

take a look at my writeup on RAF (and many other idle related things) at http://redhardsupra.blogspot.com/200...le-tuning.html

just a quick advice: for Idle tuning, set your scans to g/sec, as the numbers come out much more precise than in lb/min so you get 20g/sec as compared to some 0.07lb/sec or something. same thing, better display.

WS6FirebirdTA00

iTrader: (33)

from what i have found the RAF has nothing to do with the ac airflow, of course if its in line the better but what all the guys are saying about increasing adapt idle limits is a good place to start at if all your other idle stuff is inline

MNR-0

I cant see any specific RAF value for AC on. However, I can see PID airflow decay rates for AC ariflow. Try doubling the Proportional and Derivative decay rates if your AC increases airflow ridiculously high and see if that helps.

gameover

AC airflow is torque based. You can try increasing the AC torque numbers under Engine -> Torque Mgt, Engine Torque if your STITs are moving too far positve when the AC is on.

Chris...