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jguerdat
07-03-2013, 12:29 PM
Anyone know when the A/C kicks out for acceleration? Is it based on RPM? Boost? Throttle position?

DS Ocampo
07-03-2013, 12:59 PM
My brothers dart does it when he hammers the throttle then as he releases it kicks back on

13VaAbarth
07-03-2013, 11:34 PM
I believe with most newer cars the A/c turns off at full throttle and comes back on when not full throttle so im gonna take a guess and say the abarth does that too.

jguerdat
07-04-2013, 10:54 AM
I know my S2000 kicks off at 7800 and back on at 7200 RPM. However, that's known because it's been datalogged. I was hoping someone with a service manual or access to engineers would be able to find out the gory details.

msjulie33
07-04-2013, 11:32 AM
It's been blazing here the last week, so rather than top down it's been AC use - what I notice is that in any acceleration which isn't just deathly slow (very gentle) the air temp from the vents raises up momentarily leading me to believe my little Pop disengages the AC quite easily in order to keep the massive 101hp available for moving the car.. it's not a big deal because for my in-traffic driving it's mostly first gear and a small bit of 2nd gear before the temp cools back down. Maybe the higher HP engines can be more generous with the AC load ...

Fiat500USA
07-04-2013, 12:03 PM
I know my S2000 kicks off at 7800 and back on at 7200 RPM. However, that's known because it's been datalogged. I was hoping someone with a service manual or access to engineers would be able to find out the gory details.

I looked and it is not in the manuals. Looks like there is a clutch on the alternator, too.

https://lh4.googleusercontent.com/-wAJMbMGtzCY/UdWZ64tfXjI/AAAAAAAARoE/qisp2RjtPCY/s640/AbarthPower.com-Fiat_500_Abarth-2012_NY_Auto_Show%2520051.JPG

jguerdat
07-04-2013, 02:18 PM
Hmmm... On the alternator, eh? That's a new one. Maybe both are something that can be monitored via the OBDII port and Torque...

BTW, this is related to forgetting to turn off the A/C when autocrossing.

SailDesign
07-04-2013, 02:56 PM
BTW, this is related to forgetting to turn off the A/C when autocrossing.

Self-inflicted :D

Vaejovis carolinanus aka lowconabarth
07-04-2013, 06:39 PM
While at the Abarth experience the instructors told us that the A/C shuts off when the throttle is fully engaged.

Fiat500USA
07-04-2013, 11:12 PM
Hmmm... On the alternator, eh? That's a new one. Maybe both are something that can be monitored via the OBDII port and Torque...

BTW, this is related to forgetting to turn off the A/C when autocrossing.

A little info on the Alternator clutch or:

Overrunning alternator pulley (OAP)
Alternators have the largest inertial torque in an accessory drive, greatly affecting belt drive behavior. An OAP decouples its inertial torque from the cyclic irregularities of the crankshaft in an internal combustion engine.
Since 1996 the OAP satifys our costumers by its outstanding cost-benefit ratio. Due to continuous development, we were able to accomplish the increased costumer requirements and to support their innovations perfectly.
Besides its reliable function and its contribution to CO2 reduction and therefore fuel saving, the OAP convinces of its solid construction, as well as with its technical support worldwide. Due to this general concept the INA OAP is the absolute world market leader of alternator uncouplers.

Advantages
The positive effects on the accessory drive include:


Minimization of belt vibrations
Reduction of force peaks in belt drives
Reduction of tensioner movement
Increase in belt life
Improved noise behavior in the belt drive
Reduction of belt slip on the alternator pulley during upshift (particularly in fast shifting dualclutch and automatic transmissions)
Less strain on the overall system during engine start and stop-and-start function
Preload force reduction in the overall system, leading to reduced CO2 and frictional loss



From Schaeffler Technologies AG & Co

jguerdat
07-05-2013, 07:59 AM
Self-inflicted :D

Yeah, it is. chairshot

It's hurt me a couple of times when autocrossing where a Christmas tree is used (ProSolo and the Abarth Experience head-to-head). You get your timing right and then forget the extra drag, allowing the tires to bite just that much sooner, and you get a red light.

BTW, don't forget that any climate setting that involves the defroster (doesn't have to be JUST the defroster) uses the A/C. Learned to set that to just the lower vents quickly.