Syonyk

As it warms up, I've been using the AC quite a bit, and I haven't been able to determine if my S4 cuts the A/C compressor off at WOT. I know a lot of newer cars have a built in feature to cut the AC off under high throttle loads to get more power to the wheels. As near as I can tell, the S4 ECU doesn't do this.

Would there be any interest in a device that added this feature? I'm working on a small add-on board to add a lot of neat readouts to the ECU, and it would be fairly trivial to add an AC cutout feature while I'm designing it.

-=Russ=-

NZConvertible

The S4 does not have this feature, but the S5 does. You can't effectively use the S4's narrow-range TPS to do this, as only the first 1/4 or so of the throttle travel is actually measured. If you used this the A/C off would be cut too often. The S5 has a full-range TPS as well as the narrow-range one, and this is used to switch the compressor off at more than half-throttle.

A better idea would be to use a voltage switch like this one (or one of you own design) to monitor the AFM voltage and cut the A/C when load reaches a certain point.