Struggly

I'm going to upgrade the radiator in my '93. Which is the best? Koyo or Fluidyne? Or is this upgrade not really worth it? Also, does someone make a lower temperature thermostat?

Clint Fralick
Struggly@hotmail.com

BrianK

you should do a search on this.... it's an old dead horse that new people come in and start kicking.

however, since I'm writing - yes, it's a worthwhile mod... it's actually a fairly important one that needs to be done - some people get away with not doing it but if your rad fails, you're SOL.

The Fluidyne fits right in, no problems. It's rumored that the Koyo cools a little bit better than the Fluidyne (tho I've yet to see tests) but it has some fitment issues. Both are much better than stock. I personally have the Fluidyne. Either can be had for around $400.

As far as the thermostat goes, I've heard of people using a Miata thermostat.

You may want to think about doing the fan mod too.

hapa

The Koyo is thicker than the fluidyne, so it has the capacity to cool the car better. Is this cooling usable in the real world??? I have no idea. It hasn't been proven either way. If you have a M2 intercooler, or something of similar design, I'd go with the fluidyne, the Koyo has more fitment issues since it is bigger. If your going to be road racing your car alot, then the Koyo may be better. Like I said it has more cooling capacity since it is bigger, but no-one that I know of has done any testing to prove or disprove this.

Also always use the o.e.m. thermostat as long as it functions normally there is no need for a different model. Now you might be interested in the miata fan thermoswitch. Do a search on that. Also I'd recommend doing the fan mod as well, it's easy to do. I'd also recommend getting a good h2o temp. gauge, the stock just plain sucks.

eric

RX-7 Pilot

Where is the cheapest place to find the fluidyne rad?? Also would you need it if you ran that sierra coolant?

A-Spec

www.phase2motortrend.com has the best price I've found.

I have the fluidyne now, I'm going to run the Evans soon. I think many have said that with Evans you won't need the bigger radiator. I think the stock will be ok, since the problem is with the endtanks cracking but the evans is zero pressure so it should keep it from cracking..

David

pp13bnos

iTrader: (1)

Not to mention, you never have to worry about the stupid ast splitting either. CJ

Struggly

I know this has been asked before, but will I have fitment problems if I try to install either the Koyo or the Fluidyne in the stock, slanted location? The rest of my engine is stock.

Clint Fralick
Struggly@hotmail.com

Dr Wankel

I HAVE NOT ugraded my radiator yet so this is completely hear-say but I think the Fluiy will mount in the stock location with no problems or modifications. The Koyo on the other hand suposedly will require a bit of fabbing to fit but WILL fit. Some people have had problems with the Koyo and some stock mount IC's though ( M2 Large) i think. If you have the tools available to fab a few bracket sand what-not the Koyo has a thicker core so I would imagine that if will cool a little more efficiently. The Koyo is also a bit cheaper though.

This is the best price I have been able to find on either of them. http://www.absoluteradiator.com/cgi-...c9d+1007803758

solo1seven

I have been hearing of this evans system; the radiator system is under pressure to increase the boiling point of the coolant, if you are running a 90% mixture of water and coolant with 0 pressure it will boil just over 100 degrees correct? why would anyone want to get rid of the pressure in the system. The greddy cap even increases the pressure to allow for better protection, just curious.

Andrew Wojteczko,
93 RX7 R1

RX-7 Pilot

The properties of the Evans coolant has a higher boiling point than conventional coolant+water thus no need to have a high pressure system. Which lesssens the chance of blowing up your ast and end tanks.

Kelvin