I am thinking that I will replace my stock radiator with a Koyo or Fluidyne when the time comes to complete my rebuild. I have everything off right now to where it would be easy to do.
The question I have is this: Why are there SO many diffrent and varying opinions on how 'easy' the install of an aftermarket radiator went? I mean, come on! Unless there is some weird-*** wild variance in tank size or how the bracket locations are installed on these aftermarket rads, they should all go in the same.
Some Koyo people SWEAR they just took off the stock brackets from the stock radiator and dropped it right in.
Others have indicated that they had to do everything from simple ductwork trimming to cutting away parts of the frame of the car!
Everyone seems to agree that the Fluidyne IS a simple, easy, direct OEM replacement. Well....MOST everyone!
I searched the 3rd gen section religiously and found all sorts of posts regarding the fitment issues, but nothing about WHY there could possibly BE a fitment issue!

 

bajaman....

I think it varies because we all put different aftermarket parts on in conjunction with the aftermarket radiator..

plus each of our cars are slightly different inregards to fitment.

As an example. I bought a koyo straight off after reading the same posts as you.

It really is a nice radiator and fit "fine" with my stock IC and airbox. Then when I put the rx7fashion airbox on it just fit "ok" as it was hitting the higher inlet pipe...now with my ASP medium intercooler...I can't stand the thing as it raised the IC duct making it impossible to close my hood latch!

Also with the Koyo, the radiator would sit right on top of my AC cooler.

I just swtiched to a Fluidyne last night...and guess what? Still with fitment problems...It hits the airbox inlet...but is slightly better, it raises the intercooler duct but sits a little lower...but now it is like stock with the gap between the AC condensor and radiator.

So like I said, I think the fitment issues vary so much depending on what aftermarket parts you have in your car (btw, I have the widefoot mounts, which lower the radiator a bit)

I think if you are looking for the most exact fitment for your purpose, I would try to find someone with similar aftermarket parts as you have or are planning to put in your car...that might give you the best expectation for any fitment issues in your car

IMO

 

Thanks, 7racer.

I was beginning to wonder if there was just NO quality control by the manufacturers of these aftermarket units, allowing huge differences in actual build/dimensions/etc.

As for me, I'll stay pretty well stock with the possible exception of changing to some larger SMIC, someday.

 

Bajaman

I had a little different experience with Koyo and Fluidyne radiators than 7racer. My rx7 was bone stock at the time and I had a shop put a Fluidyne radiator in or at least I thought. My air box was raised approx. 1/2" to 3/4" and asked them to fix it. They told me that was normal. Well about 3 months later my car over heated and I couldn't get an appointment with the shop that week. I ended up going to another shop and found out that the primary fan fell a part because the blades were hitting the radiator. Also the radiator was found to be a Koyo not a Fluidyne. The shop that was fixing my rx7 said that with a stock setup the Koyo won't work and that I should install a Fluidyne. I had them install the Fluidyne and I hadn't had any problems so far. Also the stock air box sits correctly know. The problem with the koyo is that it can't sit low enough to accommodate the stock air box / stock IC with out putting pressure on the back of the fans. At least thats what the shop told me.

 

Thanks, gts.

I'm pretty sure I'll go with a FLUIDYNE, there sure seems to be a LOT less problems with them vs. KOYO.

 

you should consider pwr. no fitment problems what so ever.

 

Yes, the fluidyne has less fitment issues by far.

 

I am running a Fluidyne with the PFS SMIC and intake. The front of the intake is raised slightly by the upper radiator hose, which causes an occasional light rubbing on the hood. The SMIC fits fine although you have to be careful not to smash the fan wires with the duct, as it is right up against the fan shroud.

I know you can reverse the brackets to make the Koyo sit lower (which you can't do with the Fluidyne as the "brackets" are already welded on), so this may or may not mean better fitment than with the Fluidyne.

 

PWR?

Paul Walkinshaw Racing?

 

ah ok, thanks rynberg. I'm gonna attempt the radiator install today.

 

dont know what it stands for, but everyone ive seen installed fits perfectly even with the stock ic and duct.

 

The amount of pressure isn't really significant.

First why not figure out the real reason the Koyo has "fitment" issues whereas the Fluidyne does not.

If you want the best cooling out of the set of radiators we typically talk about - you get the Koyo. I had some plastic trimming and bending of the radiator support tabs to do, that was it.

Most of the time the Koyo nor the Fluidyne are even the problems with the items above it. Even SanJoRx7 with a MazdaComp radiator had the same aftermarket airbox issues as everyone else.