I just moved t o Tampa, from colder climes, and I'd like my '93 rx7 to survive summer. Assuming I can only afford one mod right now, which should I do? Fluidyne 50% larger than stock radiator or vented hood? Or something else?

Radiator.

Well you should replace the rad as a matter of prevention. I used to live in South Texas and it gets hot down that way. A good alluminum rad and a new thermostat and you should have no problems. The vented hood would be secondary behind the rad IMO.

you fell off the face of the earth...where have you been at?

I went with the Koyo rad, I worried about whats under the hood 1st.

I agree with this. If you're really worried about underhood temperatures, however, go with a more free-flowing exhaust. All the heat is allowed to flow away from the engine instead of hang out and bake everything. You also get the added bonus of some HP. Beware though, there are cases where stock ECUs can't handle a full straight system. (There are cases where they do, but I wouldn't think you'd want to experiment.) Radiator, intercooler (bigger, stock location type), better radiator fluid, (Redline water wetter added) and better flowing exhaust should have you pretty comfortable. At least it would me. https://www.nopistons.com/forums/pub...#>/biggrin.png

A vented hood would not have prevented my stock radiator end tanks from cracking. Go with the radiator.

A vented hood just isn't what comes to mind when I think first steps towards a cooler engine bay. It's closer to the end of the line. My thinking order goes: exhaust, radiator, intercooler, oil coolers...etc. Good luck with the weather in Florida, we vacation there often (live in AL) and I know how freaking hot it gets.

While we're talking about radiators, what would be "better"? I'm not looking for opinions, just facts. Fluidyne or Koyo? (Money's not an issue, pure performance.)

Fluidyne is only 38mm thick, Koyo is 50mm I believe.



I got mine from M2, I think it's the Mazda Competition one? 50mm thick.