Just bought my 93 fd about 4 months and wanna replace the radiator. Searched around and saw a couple that I was interested in. The SR Motorsports, Fluidyne and Koyo looks good. I wanted something that bolts right in with no modifications needed. Also I live in vegas and need a radiator that can handle the damn heat out here.

 

I believe the fluidyne is a direct bolt in, as it is the same dimensions as the stock rad. The koyo is a little thicker, and this causes fittment issues for some people.

If you really want your car to run cooler, I would suggest that you install the FC thermoswitch. It turns the fans on at 95c, instead of 108c, and is a direct replacement. Check out the thread here for more info: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/its-official-do-not-buy-miata-thermoswitch-until-you-read-397156/

 

Alot of threads on this subject. A quick search and some reading is in order. With the heat where you live, increased capacity is probably a good idea. But as crcleofdst suggested, there's also other things to do for cooling that are relatively cheap.
A quick review......Fluidyne is 50% larger, usually less issues with fitment but not necessarily "bolt-in". KOYO is 100% larger than stock, generally more fitment issues. Both are quality units though. Don't know about SRMOTORSPORTS. It might be OK, but based on some things I've read about them, I suspect it's probably just a re-badged overpriced unit.

 

If you are running the stock intake and intercooler then get the Fluidyne. The Koyo is thicker and harder to install on a stock car.

Jason

 

The welds on my Fluidyne are absolute garbage. I'm glad I paid top dollar for a "reliability mod", when the damn thing started leaking from the MIG welds after 3,000 miles. They only TIG in a few spots. I swear, companies are selling shittier and shittier parts every year...

Threw my stocker back in, no problems...

 

I'd get one of these. They are pretty close to you
http://rx7.com/store/rx7/fdengine_cooling.html

 

The fitment issues they are referring to with the Koyo are that you will basically need to heavily modify your stock air box (basically cut the bottom off) or be running an open-filter style (like the HKS) intake.
One more thing I'd say about cooling is that localized boiling is what will cause coolant seal faliure, therefore getting a more hefty rad (like the Koyo) and running a higher porportion of coolant is better IMO, as it will lessen localized boiling!

 

Koyos are a bitch to fit in the stock location... Especially when you run a large intercooler...

Flyuidynes are much easier to fit. Maddslow aside there are plenty of people who did well with the Flyuidyne. For all we know his got damaged in shipping some how.

 

STAY AWAY FROM SR MOTORSPORTS

Their rad is a rebadged koyo. Not even that, they just put a sticker over the koyo tag. And the rx7store sells koyos for $370 compared to SR's $550.

 

Good point. While 70 water/ 30 antifreeze improves heat transfer, it does lower the boiling point, and makes hot spots (which can ruin the seals) more likely. 70/30 is also not as good at preventing corrosion as 50/50, even when used with distilled water.

Dave

 

I personally have been very happy with my PWR radiator. Good price and no fitment problems. It gets pretty warm here in Dallas, TX but so far so good.

 

I'm happy with my Fluidyne.

 

When I receieved the unit, it was packaged remarkably well. The leak was caused by shitty welding. Why they used MIG instead of TIG just baffles me, it just flat out looks like garbage.

 

You may want to look at ebay for koyo rads, I think they are as low as 300

 

That would **** me off too and here's hoping you were an anomaly. I had my car up in the air just the other day when a friend stopped by and remarked how nice all the welds were on my Fluidyne. I replied with some remark that it should be nice given the cost....but mine really did seem like a quality piece. And it's been in the car nearly 3 years with absolutely no issues.

 

I have a PWR and I had fitment issues. It required that I filed down the stock mounting tabs by an inch so that it would sit a lot flatter.

Keep in mind, I had the stock airbox/IC at the time of the install.

 

Thanks everyone for the info. My fd is still all stock. I'm sure going to stay away from the SR rad. I ordered a Koyo rad because of the good price I got.