Are flex fans any good? Do they offer any power or cooling gains? From what i gather they replace the fan clutch so they spin with the rpm of the engine, but they are light and the fan blades deflect and cause less drag as the rpms increase. The fan clucth keeps your normal fan at lower rpm, but adds friction and rotating mass to rob some power. Flex fans look cool and are only $20 but do they offer anything in terms of cooling or power benfit?

 

They work but you have to make sure the fan tips are matched to your shroud which you MUST KEEP and are halfway into the opening at rest. They don't cost as much HP as the stock clutch setup and are a cheap intermediate before upgrading to an electric fan which will use even less HP form the engine to run.

 

Black Magic electric fan with temp control is the way to go.

 

In reality your stock clutch fan will make more power then a flex fan. I have seen dyno numbers of 9 HP loss between the flex and stock fan. You don't want one because they are noisy and don't allow the engine to warm a little before pulling alot of CFM. The best is an eletric fan. You will need to look into a decent alternator upgrade with an eletric fan. The eletric fan will demand more amps from the stock alternator. With the right wiring connectors you can get an alternator off a 3rd gen to fit from what I hear.

 

My stock alternator was still alright with twin electric fans but it's still a good idea to upgrade.

 

I slapped a 87 T2 alternator on my 84, no mods no prob

 

9 hp?! loss that sucks I got my alternator from a junk yard but i dont know what year it is off of. It too a few spacers to mount it so it may be a TII alternator. Any other ways to tell?