As an alternative to trying to use FB/FC oil coolers that are now 20-35yrs old has anyone tried RX8 oil coolers on their first gen? Because of the way they are shaped they offer some packaging options that the FB/FC coolers don't and they are newer/available.

I use two cooler plumbed in parallel on my race car and I just replaced my last set of good used FB coolers with a pair of Chinese knock offs. The OE coolers developed core leaks and were not repairable. The Chinese stuff looks nice but I am not sure if they are as efficient as the OE pieces.

What say you??

 

I don't see why not, especially for a race car.

 

Agreed. I think Mazda had a few senile moments with the Rx-8, but I don't consider the oil coolers to be one of them. I think they would probably be fine to use on your car.

 

i'll third that. if you think about it they are sized for ~230hp@8500rpm, so its about right.

you do need to be a little wary of used ones, the Rx8's have a higher failure rate of oily bits, and the piping was more vulnerable to corrosion.

 

Thanks guys!

 

If you plumbing them in series you also loose oil pressure. Parallel would be the way to go but it's an extra plumbing challenge. Cxr had a nice ish first gen style cooler and some setrab knockoffs, I was nervous to try one due to time restraints and recently sprung for a setrab instead. So far it's exceeded my expectations.

It fits about 1 inch in front of my radiator and covers the majority of it up. At idle when the fans kick on it pulls though both with no trouble and both temps drop. Im hard pressed to reach 215 oil and 190 water(stock radiator) on track with this setup. Im pretty sure at the end the front straight I was at 200 oil 179 water.

 

How big is the Setrab cooler you are using?

My plan is to plumb the RX8 coolers in parallel and then put them on either side of the radiator. That way they aren't in front of the radiator.

 

11x18 part 50-660-7612
another thing I came across was afco makes big coolers for low prices.

 

When putting these in parallel, do you just "T" the front engine output line with a AN fitting or use some sort of block? I guessing the same method would also be used with the output of each cooler joining them back to a single input for the input at the oil filter?

 

I had originally thought about doing this a while back. My initial design was complex, and I ditched the idea after a while. I was going to run two of the RX-8 coolers in concept. I would have ran them in sequence most likely, in order to cut down on hosing somewhat. I wouldn't like how one cooler would always inherently be hotter than the other though. So I may have swapped to a parallel style system in the end. They have built-in thermostats so you can run the system without the added expense of the oil thermostat most people need to add with an aftermarket cooler setup. I'd probably run them with a single feed and single return line, running each in parallel - feed from front cover to input of oil cooler one and two, return from one and two to the rear iron of the engine.

I did make a video on how much pressure they take though, turns out they can really hold some oil pressure before popping.