Koyo HH-Series 48mm Radiator for Evo 4/5/6 (Fits 7/8/9) (HH030939)

Koyo Radiator

The Koyo radiator fit in my 96 EVO perfectly. Had to modify the factory fan brackets slightly but no big deal. STM always delivers my parts on time.

EVO V

Tight fit with a universal fan but works amazingly well coolant temps a not a thing I have to worry about anymore. STM has wonderful customer service as well. They are always helpful.

Pretty nice piece

I have always admired both Japanese as well as German manufacturing for it's inherent quality and attention to detail. That's probably why I was surprised and a little disappointed by two issues with the Koyo Radiator I purchased. Being a welder by trade and typically only a welder would see this, The beads had cold stops meaning the center of the bead cratered in and had the potential for a pin hole. almost every weld I looked at had a cold stop, yet it holds water and pressure, so not an issue. The second and sadly more obvious was even though it was very well packaged and there was no damage to the box it was shipped in, my radiator showed up with one row of fins caved in. It had been damaged, packaged and shipped. Since this is the far outer row, I don't consider it a problem as far as function. It's just disappointing to purchase something you think is going to be a nice good quality part and have it look like it's beat up before it even goes in the car. Anyway, enough with my griping. On track this radiator performs. I never had my temperature move the slightest above what the thermostat was holding. only at sustained high speed high RPM's did the temps start to creep up and they would immediately drop if I got out of it. I believe this to be more related to aero ducting than the heat exchanger, so overall, I still feel better than as if would have buying some cheap Chinese unit.