I have a coupla thoughts,,
I'm not sure I like that solid plate the fans are mounted on,, it appears to me to be blocking airflow and possibly the resulting turbulence affecting the flow of air, then the fan motor themselves block flow... jmo..
Can you not remove that whole elec fan assmbly,, and just bolt on any reg. fan you got,, with a shrould would be nice,, but just drive it with the fan,, and see what it does..
hope it helps