I had removed my engine driven fan off my V8 county and replaced it with Twin AU falcon thermo's..

I find it regualtes the temp much better and alot quicker, my thermo switch is set so they come on at 180 F.. and at idle they will run for around 30secs before the temp is back doen to around 165F...

They only ever seem to come on when doing below 60 odd km/hr. and even in stop start traffic on a hot day, they only ever run for short periods of time....

I definatley noticed the power difference once i removed the viscous fan...