On a 90 degree day, A/C on max and notch 4, what evap temperature are you runninng at and how much pressure on the high side? I am trying to get mine squared away but not sure on how good this thing should be cooling. Presently, I am at 180LBS on the high side blowing around 55 degrees. Seems a little warm to me. I can't get a straight answer from any shop. They say if it is 80 degress outside, the A/C should blow 60 and 90 outside 70 inside. I call BS. On a 94 Z.

 

The FSM for my 94 vette says 80* ambient -> 38-43* outlet ; 90* ambient -> 40-44* outlet.

My other cars' FSMs show about 5* lower outlet temps than the vette at those inlet temps.

 

http://shbox.com/1/ac_performance_chart.jpg