I know the later C4s have 2 cooling fans. Seems like that would be nice if only for redundancy. I have an 87, it has one fan. What would it take to put the 2 fan configuration into an 87?

I put dual electric fans in my C3. Since my Vette came with a factory mechanical fan, that meant I needed two separate means for controlling the fans.

Your C4 already has one fan control method, meaning that if you installed a dual fan setup, you'd need to make or create a second fan control method.

Not all that difficult. You can have it on all the time with an Ignition controlled relay, so it's on when the car is running...or you can have a temp sensor tell a relay when to turn on so it's temp related.

There is a good diagram on adding a second fan in the August issue of Corvette Enthusiast magagzine, page 88.

Joel

IIRC, I still have the 2nd fan...

Instead of going to all that trouble why not just put in one high speed fan?? I just bought a Dewitts fan that puts out 1/3 more air then a stock fan and now the temps go down about twice as fast as with the one stock fan.This seems like it would accomplish the same thing without having to mess with your wiring..The Dewitts fan just plugs in.There are other fans on the market that do the same thing but I like Dewitts.WW

That would be easier, but he wants redundancy. You'd need a make a new shroud fit. I've heard of people trying a ford Focus shroud, basically you need something with similar dimensions, head to the junkyard and start measuring.

Or you can put a pusher fan in. The Z51 came with a stock pusher fan, but it's pretty chinsy. Although it does bolt right in without any effort. The car is wired differently though than the ones with a single fan.

FWIW, fan failures seem rare on these cars and the only ones I've heard of had a hypertech chip or some other ridiculous fan control that had it on too often or 100% of the time.

The relay is probably more likely to fail than the fan.

I have heard of others who wired the secondary fan directly into the first one if that's what you're looking for.

Matthew

Buy the DeWitts fan.

Eddie

I've always heard great about Dewitts stuff, but for the price of that fan, you can go to ebay and get a 2 row aluminum direct fit radiator with (2) 12" fans included, that pull 2800 CFM total (1400 each). I am thinking of trying one myself.

DeWitts radiators are the shiznitz.

Their fans are made by Spall. Not bad, but good luck getting one at your average NAPA store, if it fails.

The upside to the OEM fans is that their motors are available anywhere, really... something to consider. And they do move more than enough air.

I have the dewitts rad with the spall fan. I ever see over 201* sitting in traffic in south texas heat.

I also have the tiny fan in front of the radiator. Does this mean my car is a Z51?

Quote:

No. It means you have B4P - radiator boost fan.
You may well have a Z51, but the booster fan doesn't
prove it.

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I can't really back this up, but I am aware of numerous both fan and relay failures, at least on the later C4's with the two fan setup. Not sure if rare is the correct description or not.

The good news is the failures are not catasrtrophic and you end up with only one fan running or no high speed operation, but still have some cooling resulting in high temps...

Most fans run nearly 100% of the time anyhow because they run with the A/C compressor which for most of us is all the time. So I doubt if the Hypertech or similiar programming is much of a factor..

In summary though, two fans, three relays----more things to fail