Quote Originally Posted by ray1970 View Post
I think a typical 1/2” impact will pull 5 or 6 CFM so you’ll likely be pushing maybe 45 or 50 psi through it effectively cutting its performance in half.
The CFM of the pump doesn't effect the PSI going to the tool, as long as the tank has at least as much pressure as your output regulator is set to.

The CFM of the pump will definitely effect how long you wait for the tank to refill in long continuous uses.