Off-roading puts more stress on vehicles than you may think. All the vibration, extreme conditions and possible damage can cause a catastrophic failure on the trail. Cooling a trail-worthy vehicle or desert racer takes more than just a radiator.
To find out the science behind proper cooling, we reached out to the folks over at C&R Racing to get the lowdown on off-road cooling systems. We will take a look at different types of coolers that can be used in off-road applications, and how it all works together.
Keeping Temperatures Down
Desert trucks relocate the radiator to the rear of the truck for added protection from rocks.
We talked to Jeff Horton of C&R Racing to find out more about what they do to help keep our vehicles cool. “With a full staff of engineers, C&R Racing approaches radiators with a clean sheet of paper, calling upon its 15 years of experience gained from designing and fabricating F1, NASCAR, and IndyCar cooling systems,” Horton explained. “Cooling systems for these types of race cars are the most highly stressed and sophisticated of any vehicle, balancing cooling ability, weight, aerodynamics, and durability.”
C&R Racing offers a wide range of products, from OE replacement to one-off custom radiators.
“For many off-road enthusiasts, radiators are an afterthought,” Horton said. “But anytime you increase the horsepower in your vehicle, or load, say with bigger tires and lower gears (anything that builds more engine heat) it requires an upgraded radiator and cooling system.”
“LS and Hemi engine swaps are extremely popular with the Jeep crowd, but the OE six-cylinder cooling systems are totally inadequate,” Horton continued. “C&R Racing builds cooling systems specifically for these popular high-performance swaps with all of the plumbing hookups in the correct location.”
In general, C&R builds its off-road radiators like those for any other vehicle, beginning with the design process, fabrication of the aluminum components, and then heliarc welding them together. However, off-road radiators require special attention to cope with impact and vibration, such as rough terrain, mud and debris, and rock damage from being peppered by other vehicles. Therefore, C&R engineers take these factors into account and specify thicker tanks, mounting flanges and related components.
Think your truck can withstand the test? You may be surprised to find your radiator is a weak link.
C&R engineers take these factors into account and specify thicker tanks, mounting flanges, and related components. C&R also employs some proprietary technology, including replacing traditional roll-tube cores with an extruded tube core that is much stronger and more efficient.
“C&R’s fins have folded (doubled) leading edges that can stand up much better to damage from flying debris,” Horton explained. “Another C&R feature is that the corners of each radiator are gusseted to maintain integrity during harsh impacts, such as jumps and those bone-jarring whoop-de-dos.”
Radiators And Racing
The more extreme classes of off-road racers like Trophy Trucks and Dakar racers require special radiators. “The higher-end racer usually locates the radiator in the rear for improved weight distribution and protection,” Horton said. “Also, these environments are extremely dirty, so the radiators are designed with a very open fin density (a low number of fins per inch) to prevent clogging.”
Adequate airflow is ensured with a properly designed duct system, fan shrouds, and high-performance electric fans. All of C&R Racing radiators use Spal fans.
C&R Racing uses Spal fans on all of their radiators and external coolers.
Since bleeding the air out of a remote radiator can be difficult, the use of a remote surge can or C&R pressure can is required to ensure that all of the air makes its way to the highest point and out of the radiator and engine. “C&R’s extruded tube radiators have three times the pressure rating of traditional aluminum radiators,” Horton continued. “You can run them at higher pressures to raise the water’s boiling point. This prevents the formation of steam pockets that lead to overheating.”
There are many factors to consider when upgrading your vehicle to an aluminum aftermarket or racing style radiator. Technology, efficiency, durability and fit should be the key factors in your decision. A low-cost imported aluminum radiator might just fry your expensive engine and leave you stranded somewhere out there on the trail or racecourse.
We have reached out to Terrible Herbst Motorsports, the well-known builders and racers of Trophy Trucks in the SCORE and Best in the Desert race series. The team uses C&R Racing equipment including radiators, oil coolers, transmission coolers, and power steering coolers on both of their trucks.
“Reliability and performance are two of the big drivers,” Mike Smith of Terrible Herbst explained. “Cost is definitely a factor, but the product has to be able to live and perform in our extremely harsh environment.”
The power steering cooler can be seen through the front of the Trophy Truck.
In addition to the elements, fluid temperatures also come into play. “Our coolers see a wide range of temperatures during a race,” Smith said. “Our radiator gets to 220 degrees Fahrenheit, oil cooler to 300 degrees Fahrenheit, transmission cooler to 300 degrees Fahrenheit, and our power steering cooler sees temps up to 300 degrees Fahrenheit.”
“The ambient temperature gets pretty gnarly at times as well,” Smith explained. “Last year at the Baja 500, inside the cab of the truck, the temperature of the ambient air flowing into the coolers with the truck moving at over 120 mph was 130 degrees.”
Terrible Herbst Motorsport's radiator and coolers outside the truck.
On a machine like a Trophy Truck, every piece is important. “We look at three big factors,” Todd Grouch of Terrible Herbst explained. “We look for durability, weight, and cost. The C&R coolers are lighter with the same or better durability at the same cost of others on the market.”
If you can learn anything from the pros, it is to mimic what they do. They have the budget and the vehicles to do the testing. Whether you are looking for a radiator for your race truck or your trail rig, making sure that you have the proper cooling is key.
For more information on C&R Racing and its products, be sure to check out its website.