Wrong DA?

I have a a 80 gallon 5hp compressor 15 c.f.m

I am also using 80 grit dura gold paper. The car has the original paint with one base coat clear coat paint job. I was being patient but its seems like it is taking a long time.
For me, 80 was all I ever needed. And I used the Gold 80 grit DA paper, 100's of sheets for a car. Need to keep it changed often.