A/C Driving tuning w/HPT?
What do I do? I am a rookie at best and have no idea where to go from here to get the rpms to come down and drive normally. Could someone look at my bin and provide suggestions?
Thanks.
Jim
email your bin to fredsanford2003_AT_yahoo.com
ill look at it tonight
In the meantime, if you got time, there are settings all over the place for the AC. Look around in the editor.
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You want your dynamic air to match your idle airflow at idle with and without the a/c running. This usually means a pretty steep ramp (15 count increase per cell) on the IAC counts, but once you get past the idle level with A/C on (let's say 90 counts just for grins), you'll want to flatten the curve to around 5 counts increase per additional cell. Try that and see if it helps any. It helped me.
Mine look like this:
starting at cell 22.0
1,3,8,15,30,45,60,76,92,100,105,110,115,120,125,13 0,135,140,145,148,151,155,161,165...(increasing all the way to 260). If they look strange it might be because I'm running a Nick Williams 90mm TB, but the principles are sound.
Hopefully, this will help.

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You want your dynamic air to match your idle airflow at idle with and without the a/c running. This usually means a pretty steep ramp (15 count increase per cell) on the IAC counts, but once you get past the idle level with A/C on (let's say 90 counts just for grins), you'll want to flatten the curve to around 5 counts increase per additional cell. Try that and see if it helps any. It helped me.
Mine look like this:
starting at cell 22.0
1,3,8,15,30,45,60,76,92,100,105,110,115,120,125,13 0,135,140,145,148,151,155,161,165...(increasing all the way to 260). If they look strange it might be because I'm running a Nick Williams 90mm TB, but the principles are sound.
Hopefully, this will help.
Thanks! I'll give this a try.
Jim
Idling the IAC count is up between 130-145. Idle Desired AF & Dynamic AF are off by about 2.5g/sec. w/the A/C on. A/C off I get none of these issues. Car drive pretty good for all the mods.
Last edited by Jimmyz; Sep 28, 2005 at 01:44 PM.
TB blade and the TB is at .59 cracked.
jim i am looking at the log with the ac on and the airflow trims chagne a good bit with it on. it wants to pull out a lot of air, about 1 g/sec more than regular idle. the effective area can be tweaked more now that the ve was changed but it is only off by about a half a g/sec which it SHOULDNT make it that bad.
patrick, from a cold start the 2 airflow lines match each other very well, well they are slightly off now but before they were dead on. even with the ac on they match. what ac parameters can be changed? or what idle settings may be screwy. like i said, i have never tuned a cammed car with a/c since mine is gone so im lost. we tried some stuff but it didnt do ****
What do I do? I am a rookie at best and have no idea where to go from here to get the rpms to come down and drive normally. Could someone look at my bin and provide suggestions?
Thanks.
Jim
Bump this value to 3.0-4.0 g/sec.
Ideal fix -> AC Compressor Torque The AC compressor places a large and variable load on the engine when engaged. The PCM has a complex model of AC Torque load including inertia effects and ramp in/out when the AC clutch first engages. The AC torque calculation is also used to calculate the Idle AC Airflow compensation for IAC/ETC control during idle.
Torque vs. AC Pressure: This is the torque loss of the AC compressor versus AC Pressure.
Torque vs. IAT: This is the increase in AC torque loss due to inlet air temperature.
Inertia Torque: This is the model of inertia torque load for the AC clutch when it engages.
These three tables need to be adjusted for increased TQ loss (need more airflow). You might try copying the tables from a Holden VY SS - just a guess though.
Bump this value to 3.0-4.0 g/sec.
Ideal fix -> AC Compressor Torque The AC compressor places a large and variable load on the engine when engaged. The PCM has a complex model of AC Torque load including inertia effects and ramp in/out when the AC clutch first engages. The AC torque calculation is also used to calculate the Idle AC Airflow compensation for IAC/ETC control during idle.
Torque vs. AC Pressure: This is the torque loss of the AC compressor versus AC Pressure.
Torque vs. IAT: This is the increase in AC torque loss due to inlet air temperature.
Inertia Torque: This is the model of inertia torque load for the AC clutch when it engages.
These three tables need to be adjusted for increased TQ loss (need more airflow). You might try copying the tables from a Holden VY SS - just a guess though.
...sorry. Use the "AC Offset Min - In Gear" - add 1.0-1.5 g/sec. It will "Learn" the correct offset value. My understanding is the Ramp in and Ramp out rates as well as the A/C torque tables will need refinement. You can scan the A/C pressures.
You might try reducing the A/C Ramp In (and Ramp Out) by 1.00 g/sec across the board.



