Phase XI - PWR Radiator Installed

By now the summer Phoenix weather is just about to go into full swing and with that comes the scorching sun and mind cooking heat. Typically throughout the summer we see temps averaging around 110 and often in excess of 115 degrees. It doesn’t take a rocket scientist to figure out what that does to a car. On any given summer day it would be hard to make it though the whole day with out seeing at least one over heated car on the side of the road.

Been there, done that …never again. It wasn’t even an after thought, I new I’d be replacing the stock radiator for some thing with larger fluid volume and better cooling before I signed the dotted line. It just makes good sense, when living the desert with a rotary. We have done it on our other project cars and it works. For example the project EVO, 420 whp, daily driver in 115 deg temps and never had an over heating issue. For such a vital job we have trusted PWR and their quality products. A call from PWR gave us the green light and they sent us a "prototype" to test fit.

If you’ve never looked through the gill to see the radiator you should check it out. It has plenty of breathing room. Angled at 45 deg, it also makes for plenty of workspace. Dropping the under pan is a snap and comes of in one huge piece reveling the entire underside of the engine bay. Form here the radiator is completely visible and I got a better look at the A/C condenser mounted in front of the radiator. Maybe PWR makes condensers as well? Hmmm. Draining the fluids is first priority. Once that was done we needed to unfasten the upper and lower coolant hoses. The bottom one wasn’t bad though the top one proved to be a challenge though with a little patience and a lot of hand dexterity I was finally able to free the hose. From here the radiator was unfastened from the A/C condenser unit and the electric fan frame. With nothing holding it place we expected it to just slip out and into our hands but no, somehow Mazda managed to make the entire coolant unit so tight and integrated that we had to separate the A/C unit from the radiator while pulling down on the radiator. This required two people on pulling the radiator, the other pulling apart the A/C unit and fan unit. We carefully wiggled it out with out damaging the cooling fins on either the stock rad or the A/C unit.

Comparatively the stock unit is wimpy to say the least and uses plastic end tanks while the PWR is almost 2.5 times thicker and is crafted from lightweight aluminum. Being that is thicker than stock it would take some extra patients and wiggling to get the PWR sandwiched in-between the A/C unit and the fans. Once it was settled in we refastened both the fan shroud and A/C. Now it was just a matter of those damn hoses. The bottom one would be easiest so I left it for last and tackled the top hose. The cramped space was now even more cramped and it took about solid 7 min to get the clamp secured. It’s literally a blind install. Luckily I am the Jedi master of hose clamps. The bottom hose was connected and clamped. A last check to make sure all was in place and secure and the car was replenished with fluids, caped off and we started her up. When you do this let the car run till it reaches normal operating temp and then check for leaks. As the fluid heats up with the engine the pressure increases making leaks more obvious. We had no such problem and replaced the large plastic under pan.

Since the install a few months have passed and we are now neck deep in a Phx summer. So far the highest temp registered on the RX8’s inboard ambient temp display was 118 deg. And it will get hotter. The PWR has been performing well through out the daily driving, stand still traffic and a few road trips though the dessert. Unfortunately it’s still common to see cars stuck on the side of the road with the hood up and steam rolling out from underneath. I take comfort in knowing that it won’t be me.

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