Performance Radiator

Radiators & Their Functions

Before we discuss performance radiators, its important to understand how the radiator works. Your factory engine before any modifications produces high heat.  To prevent your engine from overheating, your car pumps coolant through the engine.  This fluid receives the heat and carries it away from the engine block.   The coolant takes the heat generated from your engine and moves it to your radiator. The radiator blows air across the liquid, cooling it down, and exchanging heat with the air outside your car.  The coolant is passed through thin metal fins that allow the heat to flow to the air outside your car.  To sum it up, the main purpose of the radiator is to cool the coolant, which then cools your engine.

Your cooling system is made up of several components.  The core is the largest part of your radiator and provides its primary function.  It consists of a large metal block, and small metal fins which allow the coolant to vent heat to the air surrounding the radiator. There are many types of cores, such as one-core, two-core, or even three-core radiators. 

Do I really need to upgrade?

Now that we understand the function of a radiator, let’s talk about why it’s important to upgrade to a performance radiator. As stated earlier, your factory engine produces high heat from normal daily operation.  When upgrading your engine with any modifications, you increasing your heat output.  Your OE radiator is only able to withstand so much heat and pressure, and is not designed for your new upgrades. If your cooling system, especially your radiator cannot properly dissipate the heat, your headed for disaster. Since your cooling system is closed, the pressure and boiling point will both continue to rise during use.  If the coolant temperatures rise past the radiator caps pressure rating, the radiator will boil over and create a large mess, and a huge headache.

Performance radiators are designed to have greater heat dissipation.  There are many differences when you begin shopping for a performance radiator. Its important to understand what they are and how they work so you make the best decision for your vehicle..

Downflow Radiator vs. Crossflow Radiator

Crossflow vs. Downflow                                  

There are two main styles of radiators: Crossflow radiators and Downflow radiators.

A crossflow radiator consists of a vertical tank on each side with a series of cooling tubes and fins making up its core. In a crossflow system, the coolant travels horizontally across the core from the inlet side to the outlet side with help from your water pump.  This system has gravity working against it, which has the radiator holding onto coolant a little longer.  This allows the heat to dissipate a little bit better. Crossflow radiators typically have a larger core surface area as well.  This style is often the best choice for high-rpm, high-output engines.

A downflow radiator has tanks that run horizontally at the top and the bottom.  The coolant enters the top of the radiator and travels vertically through the core and leaves through the outlet at the bottom. Since the coolant flows from top to bottom, the water pump is aided by gravity.  Due to this set up, the coolant travels quicker through the radiator. Downflow radiators are favored due to their original, nostalgic appearance.  These radiators are often able to fit where crossflow radiators are not able to.

Mishimoto Aluminum Radiator

Aluminum vs. Copper

There are many types of radiators available in the market today.  They can range from the type of material used, to the amount of cores.  When browsing through manufacturers you will come across both aluminum and copper/brass radiators.

Copper/Brass radiators are common on old school vehicles. Copper is a better conductor of heat then aluminum, however they are a relatively weak material when compared to aluminum. To avoid ballooning or busting under pressure, the diameter of copper-brass tubes that carry coolant need to be kept small.   Aluminum radiators, due to their increased strength, are able to use wider diameter tubes.  These larger tubes mean more tube-to-fin contact surface area, which allows for better heat dissipation.  Additionally, Aluminum radiators are more light weight.  An aluminum radiator can weigh up to one-third less than a comparable copper/brass radiator of the same dimension. In conclusion, aluminum radiators tend to be a more popular choice for aftermarket performance.

KOYORAD Copper Radiator

Tube Size vs. Row Quantity 

When browsing radiators, you will come across one-core, two-core, and three-core options. The usual advantage of a multi row system is you gain additional capacity for coolant.  However, It’s important pay attention to the diameter of the tubing within these cores as well.   Getting a 3 core system, with smaller tubing may not cool your car more effectively than a two core system with larger tubing.  Another important thing to pay attention to these systems would be the number of fins per inch.  The more fins, the greater the cooling area and more efficient your radiator becomes.

When looking into a performance radiator for your vehicle it’s important to keep these key factors in mind:

  • Engine Size & Compression ratio
  • Horsepower output & torque
  • Intended vehicle use
  • Type of fain (electric or flex)
  • Transmission type
  • Available space within the engine compartment

Additionally, because there are so many specifics when deciding what performance radiator would benefit you and your vehicle best, it is highly recommended to speak to a professional before making a purchase.  To ensure your vehicle continues to run at optimal performance, it’s important that the correct components are used throughout your system. A professional will be able to help you make a more informative decision.