Quote:
Originally Posted by Dustin@Z1
 No problem sir!
The drop in temp may be because the Aux fans kick may automatically kick on when the A/C is cycled on. I have honestly never paid any attenion to the 370Z and how this behaves. But I know most old school vehicles did this. |
The behavior varies by vehicle design, but I too have definitely observed that a Z with normal ECU settings runs colder with the AC on. This seems counter-intuitive at first since the AC should be (a) adding engine load and (b) adding a little more heat back into the radiator via the condenser (the heat extracted from the hot air to make it blow cold). However, as noted by Dustin above, it's the fact that the ECU turns on the electric radiator fan(s) more often that makes up the difference and then some, due to increased airflow through the radiator (esp at lower speeds).
UpRev can now control this behavior: there are independent settings for AC-on vs AC-off which control fan duty cycle -vs- water temps. Aside from turning them on earlier in general, you can set the AC-on settings the same as AC-off and then you don't have to turn on the AC just to get the fans going.
Thread here:
Fan Control now available!