In the last issue of Drag Racing Online, we took a detailed look at aluminum radiators, examined how a high quality rad is built, and determined how a well-engineered piece can really help to cool a hot-headed racecar. Aluminum works as a drag racing rad material. That’s a given. But another big (and we mean BIG) key to cooling your bracket car is the fan along with the fan shroud. They’re both far more important than you might think, as you will soon see.
Here’s an example of a cooling fan arrangement Ron Davis uses and recommends. Take a very close look at the shroud. It completely seals the back of the radiator. Surprised? You shouldn’t be. This is perfect for any hot-headed bracket car (or other drag car for that matter). The concept here is to literally force all of the available air to flow through the rad. This results in maximum cooling performance. (Ron Davis photo)
Fan Dangled…
When it comes to hot lapping your bracket car, one of the secrets is the use of a proper fan. It should come as no shock that electric fans are pretty much the norm in drag racing. But there’s a catch when it comes to fans: You have to get something with sufficient power to cool the car, but at the same time, get something that doesn’t have a ridiculously high amperage draw. This is critical for most bracket cars, because there isn’t a charging system in place. Remember, in a car without a charging system, the performance of the fan diminishes through the trip down the quarter mile. And if you don’t have the luxury of a tow vehicle at the end of the track, the situation is compounded since you have to drive back to the pits. Making this scenario even worse is the fact the vehicle speed is rather slow on the return road. Slow speed equals low airflow through the radiator and that can result in overheating. Remember too, if the fans consume too much amperage, then something else might suffer (for example, your electric water pump, your electric fuel pump, your ignition system, or even things such as bracket racing electronics).
Given this situation, Ron Davis Racing Radiators spent considerable time researching cooling fans that fit the needs of bracket racers (big volume, low amperage draw). Davis offers a trio of fans with 12-inch, 14-inch and 16-inch diameters. The (very) basic specs are as follows:
Part Number Diameter RPM CFM
EF 120 12-inch 2300 1576
EF 140 14-inch 2400 1828
EF 160 16-inch 2400 2197
There something that is important here. See the added weather strip seal between the fan and the radiator? This high temperature seal increases fan efficiency by a considerable margin. It’s like adding a shroud to a conventional engine-driven fan.