Originally Posted By DrCharles
Originally Posted By maximum entropy
yeah, the electric freed up a couple of horsepower, but what good is that when you're stuck in a traffic jam, or hot lapping, and the temp is ratcheting upward? i'll gladly trade 10 hp for stonewall reliability.


The electric fan moves the same amount of air whether idling or high rpm. However, the mechanical fan is moving MUCH less air at idle, which is exactly when you need it the most. work Fan clutches help by slipping at higher rpm but now there's another source of reliability problems.

What kind of "hot lapping" are you referring to?Any time the car is moving over about 20 mph the fan only gets in the way. If you're overheating while moving, either the airflow through the core is insufficient, or you don't have enough radiator. The type of fan won't matter here.

Finally, it's not "a couple" or even "10 hp", didn't you see the fan test article (and other similar tests)? Would you gladly give up 30 or 40 hp?
Those #'s are "SLIGHTLY" high - IMO. I won't quote any numbers, but most electric fans actually run slower at idle and how much slower will depend on just how much your alternator is up to the task at idle, where it supplies much less current. A flex fan actually works just the opposite from your explanation. There is much less HP loss at speed ( higher rpm's ) where the blades flatten out -( reads "FLEX" fan). No one on this site really cares what the HP loss is at idle. They're just concerned with cooling. And as I said, todays cars are designed from the ground up for electric fans. They have well over 100 amp alternators with a very fast current rise curve ( very small pulleys, serpentine belt driven ) and they are cooling sewing machine motors that seldom see 5K rpm. - Apples and oranges. Flex fans don't use ( or need ) a fan clutch. Stick with your Doctor's hat.

Last edited by Crizila; 02/07/17 02:34 AM.
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