JScott81

Has anyone tried installing a C5 dual fan setup in an C3? I have been looking for an affordable dual fan setup for my 81. It looks like the C5 setup is pretty thin. I just wonder if the width and hieght would be an issue. I tried to add pics but was unsuccessful. I'll read up on posting images and try to get them on.

Any comments appreciated

markdtn

I have C4 dual fans on mine using a 76L-81 core support. You have to cut the plastic down a little, but it works great.

JScott81

Hey marktdn,

What was involved in getting the primary and secondary fans to function as they should. Meaning the primary on all the time and the secondary kicking in when it should and shutting down when appropriate.

markdtn

Mine turn on by grounding relays. I have TPI on mine so the primary fan is controlled by the ECM. The secondary fan has a temp switch in the head (from an 89 350 IROC) that turns the second fan on if it gets too hot. You could use a temp switch in the intake with a lower turn on temp (maybe JET Products) for the primary fan if you don't have a computer. Be sure if you have A/C to turn one on with it or your head pressure will go high. This can be accomplised with one of the relays if necessary.

markdtn

See http://www.idavette.net/hib/bbfh7.htm for a nice article on this. The controls would work on any dual fan setup.

JScott81

Thanks for the info. Lookin forward to getting rid of the power robbing fan and clutch assembly.

GATOR454

From what I understand the dual fans from a 2000 camaro also work nicely.

You can look here for controls
http://centechwire.com/catalog/cooling/fc2p.shtml


http://www.wire-works.com
Look in the online catalog under Cooling Fans

David

Fevre

Always wonder why you would want them to independant of each other, seems you would want it to cool it down as quick as possible then shut of, less running time on the single fan that would be running more often and then both would prolly wear out at about the same time. Guess if they both go south at the same time then you are SOL but I never could quite understand why you would want you eng to heat up enough to activate the second fan, why not just keep it below 1 set temp of your choosing? :confused:

JScott81

One of my other vehicles is a 1992 Chev Lumina Z34 coup. It has the dual fan set up and it seems to do well regulating the temp at a consistant temp. The primary keeps things at about 190 deg. The secondary kicks in only when the air cond is activated or the vehicle sits at an idle on a hot day or its just plain hot as hell outside.

I guess reason would have it that it is better only to invoke the secondary fan when necessary to maintain the 190-200 range rather than kicking in both fans at 200 cooling to 170 shutting down till 200 then cooling to 170 and so on and so on and so on.

Maybe it is like conditioning the air in your home. It is more efficient to keep the level at 72 rather than cooling down and shutting off then cooling down and shutting off and so on.

70 LS1

I don't think that is how they work. I am using dual fans from a 99 LS1 Camaro and they work differently than you would think.

The fans are wired through three relays from the factory. They are wired in series for slow speed and parallel for fast. The run in slow until a set temp (220ish) then they shift to fast until (200ish). The C5 uses the same setup. The water temp sensor sends a signal to the computer which then grounds either two or three of the relays depending on speed.

Fevre

Now that makes more sense to me. :thumbs: