I am driving a 63 Pontiac Catalina convertible. Had it for about 10 years and the first modification was a new engine and trans. LT and 6 speed trans out of a 15 silverado. Had to adapt an A/C and found a unit out of a 96 Crown Vic that could be adapted. I got it in the available space but with all the ductwork I needed to manufacture with the fan in high it has the air flow of the average unit with the fan speed on 2 of 4. All the twists and turns cause so much restriction that I need a much more powerful fan. What is the most powerful firewall mounted fan that I can adapt to my mess? I am using the silverado compressor, condensor and evaporator so cooling is not an issue. I can get a 40 degree outlet temp on a hot So.Cal. day so cooling is not the issue but with a rag top and uncoated windows the heat loss is terrific. I need more airflow. I figure what I missed in design I can overcome with horsepower. (50's thinking) I will probably need to build a fan housing so are there any general rules for design. I built the current housing and with the inside unit out it is pumping a hurricane through the firewall hole but apparently there is too much restriction and possibily lack of power that is killing the present unit.
I dont know how the factory air was constructed but I do know that they had massive air flow and I would rather not have to re-design my unit.
Thanks, Dwight