Recieved my 4.5 PEAK HP unit from HF toady....while breaking cylinder [ run 1/2 unloaded / open 1/4" port] I realized it built up to 45=6 psi... Who's can do the calculations? I'm not at home...is it 11 CFM ? My 5hp 2 stage could get up to 68psi. My 1hp 2 cyl. Craftsman 8psi. Matt