Controlling the Heat: Koyorad Radiator

Do not overlook your radiator cap. This is an important part of your cooling system and the Koyorad comes complete with a high pressure unit. The rad cap is designed to work up to a certain amount of pressure – yes, Virginia, radiators are a pressurized system and that’s why if you open them when hot there will be a geyser almost as big as Old Faithful – and when if the pressure gets too high the cap will release it. The cap has a built in blow off valve, so to speak. But, don’t use a high pressure cap unless everything else in your build is prepared for it. Add too much pressure and you could create problems (gasket leaks, radiator leaks, etc.).

The Koyorad is in place position right behind the Vibrant intercooler. And if you think that completes the cooling system update then you will be wondering what I’ve been doing working on my car for the past few days. Scott Oshiro at Koyrad was quite clear during our phone interview that the rad is only one part of a complete cooling system. It cannot work effectively unless every other aspect of the car’s cooling system is also being effective. As the NX’s engine bay is not designed for a turbo, that also had to be considered. In our earlier article we addressed the exhaust heat in the engine bay with HeatShield Products. Now time for a look at a few more things that were addressed in order to have a sustainable and durable cooling system.

The bolt tabs are perfect for a stock Nissan rad fan – and the tabs are there for a twin fan setup. I, however, am not using a stock Nissan rad fan therefore I will have to be a little bit creative.

In this duplicate pic I want you to focus your attention to the nose openings and my vented track hood. Long time readers will remember when I dropped this hood off at a high school shop class with a few chalk outline on it. It went through a few classes before it was successfully completed. Sort of. And over the years I’ve just kept cutting it up. The most effective vents were the ones right behind the rad. When I cut the nose openings a few years ago I was trying to improve air flow to the rad but also imitate the Pulsar GTi-R’s grill.

But now is the time for fresh air and lots of it. Therefore, it was time to go big. Well, as big as possible without removing the front bumper rebar.