How about the same setup you have now, but add an electric fan clutch that is actuated by temp. Best of both worlds, lots of cooling pwer, but no waste of enging power.
Cheaper still is to damper the inlet or outlet of the fan. You could do this by putting one of those cold weather covers on your radiator like the big trucks do. Easy to adjust for current conditions too.Glad things are working out
The MCI blower draws air in thru a round inlet and then dumps it out a square opening down on to the engine. I don't understand how vacuum and air flow affect horse power so forgive me if this question is stupid. If I were to put a restrictor plate over the inlet to reduce the opening size I would reduce the amount of air flow. How or would this reduce the hp required to run the fan? Wouldn't the vacuum effect cause more HP to be used instead of less?
doesn't your bus have shutters at the radiator and shutter doors on each of the blowers?