i hear about i have 2 fans, on is manual controlled, or this and that, what is the best fan set up for an engine? i have a 89 iroc z and want to know how i can keep her runnin cool, especially in my chicago summers in traffic. is one blowing in and one blowing out a good idea, or is something else better? any info is awesome.

~~mike

 

The dual fan setup is probably the better choice than single. It covers more surface area. Unfortunately the factory designed these to come on at the brink of over heating. The drivers side fan is controlled by the ECM, and the passenger side is controlled by a switch in the passenger side head. The switch is set to come on at like 220* and the ECM brings the other on at almost 230*. When i 1st got my 91 the ECM's fan was the only one running. The plug for the other had been damaged. I got the hypertech fan switch , it came with a new plug and now the one fan comes on at 176* But, since the ecm is still stock, it never comes on. the one fan keeps the car cool enough, around 210, so there is no need yet for the other one. till i get a chip that will bring the other on around the same time. So that way i can get full cooling. Hope this helped.

 

Do not reverse the fans, it will be counterproductive. With a dual fan setup the primary fan(drivers side) is run by the ECM, the secondary or aux is controlled by a fan switch on the pass side of the block. 220 is not overheating. There is a lot of discussion about this, most of it is myth. You can lower the temp of the aux fan switch to get the aux fan on sooner, however by doing this the ECM will default and turn on the primary fan as well so BOTH will be running. This places a very heavy load on the charging system and will cause the alt to fail prematurely. Most cars with electric fans allow a 20 or so degree spread to allow for some stop and go without constantly running the fan(s). Thats the engineering side and it is sound thinking. Constantly cycling the fans will shorten the life of all system components. You will see much discussion here and elsewhere about this subject, unfortunately I disagree with most of it. Put in a 200 deg fan sw with a 195 stat for instance and you will be changing the alt every year. Ditto for the fan motors. Unless your driving conditions are extreme, a properly maintained cooling system will keep your engine running fine. You might consider a larger radiator as an option rather than try to re-engineer something that is already designed correctly.

 

i use the factor fan settings however i did throw in a fan switch to turn the passengers fans on / off when ever i want when the car is on..