I just redid my A/C with Envirosafe es-12 (yeah I know it's fuel refrigerant, sue me)

I set the low side pressure @43 PSI at idle, 1500 RPM about 35 PSI at 96 degrees ambient.

Not only does my AC kick ass now, a weird side effect- it also triggered the aux fans to kick on sooner than it did before. Yesterday car said it was 103F and I was still blowing 44F out of the vents according to my thermometer, and the car runs the AUX fan well before the tstat hits 87F.

moral of the story- increase your charge pressures slightly.

rjp

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03 540I (GAK!!)
81 280E (W123)
70 LeMans Sport with pissed off Poncho 462"
1989 Silverado Step Side (under the knife- complete restomod)