I think I need a better radiator. In the summer in 100°+ heat, I'm running much hotter than I would like. Turning on the A/C is a non-option, which is a big bummer for a DD. I'm sure the radiator isn't the only problem, but seeing as how it has over 250,000 miles on it, it's probably due for replacement. The engine is also somewhat modified, which probably isn't helping. The Koyo and the Fluidyne radiators seem to be the most popular. What are your opinions on the pros/cons of them?



Also - water pumps. Is the S5 any better than the S4?



Thanks

Andy

ive only heard good things about ron davis.. not sure on availability for the rexes though

i have a koyo in my tII and it doest a great job at cooling

The Ron Davis is the best IMHO - using it on the FC, but is probably overkill for a DD. I voted for the Koyo - best bang for the buck, used tons of them on all kinds of cars with no real issues.



As for the water pump, just make sure yours works properly - get a higher psi (19lbs) cap and have the right coolant mixture and she should be good to go.

I dunno about FCs, but SRmotorsports makes the most high-quality (and expensive) radiator I've ever seen for an FD. Having worked on, ordered, and built radiators for about 7 years I have a pretty good idea of quality.

So the Fluidyne is leading in the votes. I would expect it to be better since its almost 2x the price. Is it really worth it though, or is the Koyo the best bang for the buck, as One320B put it? I have plans to modify the engine a lot more in the future and I don't want to have to re-upgrade. The difference in cost between the Fluidyne and the Ron Davis is almost nothing. I'm thinking about saving for the Ron Davis just so I don't run into heat issues again.

If cost isnt an issue - Ron Davis all the way. It is a tight fit though and may not work with some of the stock parts (I wouldnt know since my car is not stock, at all)...



The Koyo vs Fluidyne though - koyo wins... there have been issues w/ Fluidynes in the past on other cars (not an rx7 that I know of)..but my friend's miata, he got two that both leaked..gave up and bought a koyo and hasnt had a problem since.



I just feel that for the money, koyo beats out fluidyne - money saved on getting the koyo can be put elsewhere.

I used Koyo in my NA last summer, 110*+ heat. never once had a cooling issue.

I would say look for a 2 or 3 row double pass radiator

Well, thanks to Ebay, Ron Davis it is. https://www.nopistons.com/forums/pub...IR#>/smile.gif



I've read a few things about electrolysis problems. What is this and how do I fix it?