Homebuilt Mid-Engine Sports Racer

I agree Rick. These are the same fans I'm using, and cooling in S-and-G traffic has never been an issue. With that said, I've made mine where the shroud (with fans attached to shroud) can be removed in five minutes for track days. I learned the hard way to remove the fans for track days due to high-speed air forcing the fans to over-speed and self destruct. Nearly ruined a custom radiator when the blades grenaded. Anything above 25 MPH keeps the engine cool without fans. I hadn't realized air moved through a radiator that efficiently or quickly.
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Active Member
Would like toknow more about those fans and if they’ve ever been used to cool a radiator yet! Very interesting!

These are TA600DC 12V 2A industrial cooling fans made by NIDEC, model A3405-29. Each fan is 6 3/4" diameter overall and weighs 21 ounces (595 g). The fans each have a 245 CFM free-flow rating but "free-flow" ratings are meaningless, what matters is the air flow rating against the backpressure of the air flowing through the radiator. Most cooling fans do not show curves for CFM vs backpressure but these fans are supplied with those curves. If I knew the pressure drop across the radiator I could know the fan's true air flow.

I originally bought a huge radiator cooling fan to use in this project but the motor turned out to be too tall to fit under the nose. These fans were a solution to my limited space problem. I think your GT40 has more room than I do for a taller fan motor.

I have not seen anyone using these industrial fans to cool a radiator.

One note- these do look a little like the fans in a computer but they are much more powerful.

Rick Merz

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Neil, See above link for specs... Overall height is only 3.73" not too bad considering that they are very powerful for a small fan. I think that your fan setup is cool looking (because it is an original solution) and if your car is primarily a track car then it might work out well but if you need additional cooling power you might consider the Spal fans. I know that some of the Winston cup cars used them as well. They can be quick release if you use 4 bolts (as pins) and 4 springs to hold them in place, simply twist 90° and remove.

Terry, I can say that I have forgot many times to turn my fans off when at the track but I have never had a failure. I really like these fans and they will cool 600+ hp with AC on the hottest day, of course really only cooling 200 to 300 hp on the street. :)

The Spal fans that I have mounted on my RCR GT40 are a different model and are taller than the ones that my link points to

Attached is a picture of my GTD GT40 (sold it) with the Spal fans that my link points to, when you turn them on the car moves forward a little. :)



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Thanks, Rick. It is good to see that SPAL publishes CFM vs backpressure data. I see that they have a series of 10" fans too. I'll need to replace the 10" fans in my street Manta Mirage since one of its original two fans has stopped working.