How many cfm do you need for your sprayer? With your 2hp motor turning the HF pump at 2/5 of the speed for 5 hp, you'll get 2/5 of 17 cfm, or 6.8 cfm @ 40 psi.What about cfm? I guess what I'm saying is that I need this guy to pump so I can run my HVLP sprayer without it getting out of breath
Also, remember that the compressor is filling the tank, which acts as a buffer, so you can get by with lower compressor output if you're not spraying continuously- i.e., you let the compressor catch up and refill the tank when you're not spraying.
+1 on checking valves on the old pump.