It was mentioned to me recently that if I wanted to upgrade my radiator but keep the most stock fitment possible, that the Mazdacomp radiator is probably the way to go. I was told to get it from Mazda directly. Well, when I look at the Mazdaspeed parts store, it looks like it is no longer available there. Funny enough, I only see two Koyo radiators available there, including what I think is the n-flow, they call it a "dual pass".

From a little digging on the forums, it looks like the Mazdacomp radiator is an AWR radiator, and that it may be available directly from them. I suppose this is an appropriate source to get it from if I want to go that route?

Narfle, I saw in your build thread (which, I suppose I should start a build thread someday, shouldn't I?) that you bought a Ron Davis radiator. It looks like it's probably the same one that AWR uses, but doesn't have the "wings" on the sides. Did you go through any of this process when you picked your radiator?

 

It's been my understanding that Ron Davis supplied MazdaComp with radiators. I can't remember if the wings were an option of not, but the folks at RD were very helpful and I'm sure you can ask. The fitment is spot on stock. The finish and welds are very nice. It's not much bigger than stock, but I didn't and haven't had any real cooling issues with my car. If you don't mind fiddling with fitment, you could probably cool better with a bigger radiator. But, quality and fitment were top of the list for my stockish street application.

 

Just buy the newer style Koyo N Flow. It fits perfectly in the stock location. The newer one is 48mm and the older one is 53mm I think. I have the newer one and I didn't have to modify anything. It literally dropped right in. I have even fit a Greddy SMIC on top of it.

 

Always amazed (and partly jealous) how everyone seems to have drop in fitment with the Koyo N Flow. I also got the "HH" series 48mm and I had a number of fitment issues: radiator mounting guides underneath, AC condenser bracket, and the radiator mounting brackets.

Really happy with my Koyo though. One great feature is that it's already tapped with a 1/8 NPT accessory fitting, which makes water temp sensor install a breeze.

 

Hmm...it's been a few years since I did it and I didn't take photos of the process but I think I only had to move the A/C condenser bracket out of the way and then put it back in place afterwards. Maybe I even disconnected it and refilled the R134-A. Hmm...either way I know I didn't modify anything and I can still throw a stock radiator back in as if nothing happened. It was way easier than I had read about on here as I thought I was going to be in for a ball ache and have to do a bunch of BS to make it fit.

 

Unfortunately I couldn't unbolt the AC condenser bracket, so I cut off ~5-7mm of the bracket with a dremel to allow for clearance to the radiator.

 

The Mazdacomp radiator had aluminum sheet "wings" which covered most of the gap between the radiator and the car frame. The advantage of aluminum over the typical 1-2 inches of foam rubber is that at high speeds the foam rubber deforms and lets excessive amounts of air past the radiator.



Shane Racing still has the radiator listed on their website. I would give Mazdacomp a call to find out what the status is on their competition radiator or just order it from Shane Racing.

AWR Racing also lists the Mazdacomp radiator it looks like they may even have the Mazdacomp part number:
0000-01-7505 1993-95 RX-7 Manual Transmission
0000-01-7505-AT 1993-95 RX-7 Automatic Transmission


Mazdacomp lists this radiator as still available:

 

I have foam on the sides of my radiator but I have done track days before I did that with my Koyo and it makes literally no difference. The Koyo cools amazingly regardless of whether you foam the sides or not. To be honest, I only ever have to come off the track because my tyres or brakes get too hot. I have never seen temps with my Koyo installed above 101 C on the gauge or Commander and my oil temps with the OEM dual oil coolers are never really above that either.

It is nice thinking to direct as much air flow as possible but the reality is that at speed so much air is flowing through the bumper openings that it really doesn't matter as plenty is flowing through the radiator. It's also why my SMIC is more than enough with the duct on the track as well (even though I now run a small amount of water because of higher boost on the twins).

 

3-pass n-flow here with no fitment issues. I also have R1 oil coolers, A/C and a RB brace on my front swaybar, so I definitely don't have more room under there than anyone else.
I just had to fiddle around with the hardlines from the coolers and A/C, and the Koyo eventually slapped right in.

No wings/tabs though. lol I used expanding foam for a chimney to seal mine.

Also, Ron Davis is still in business.

 

Yes, there are many nice radiator options out there. The advantages of the Mazdacomp radiator is directing more air through the radiator and reducing spillage around the radiator at high speeds. This has the added benefit of reducing the amount of air being dumped underneath the car from the engine compartment, theoretically reducing the amount of turbulence and lift at speed. Also, moving more air through the radiator at a given speed increases its efficiency avoiding the necessity of having too many additional rows or an N flow pattern which contributes to additional weight at the very nose of the car. As far as stressing the cooling system, , Willow Springs Raceway in August will test any cooling system when the on-track temperatures hover around 50 °C and the car spends a lot of time at speeds over 100mph. Check out Jack Yamaguchi's book on the RX-7 and you'll see that Mazda did a lot of development there.

 

Fair point. A hot climate like So Cal means you might need all of the help you can get. Over here where at most I might be tracking on a 30-35 C day, I have not seen a benefit to either ducting my radiator better beyond the factory solution (even though I did do it as I thought it would make some sort of difference which it did not), ducting my oil coolers with those R Magic ducts (doesn't matter, oil temps never get too high anyway so I sold them), or extending the ducting on my SMIC beyond the stock duct (granted, I have just increased boost from 0.85 bar to 1.06 bar and thus added a small amount of water to keep combustion temps and exhaust temps down a bit and extend turbo life...maybe).

 

Thanks for all the input, guys, and thanks for those part numbers, mdp. I can find that PN now if I search for it in Mazdaspeed's website, wonder why it doesn't come up when I search for FD radiators--it's not listing it as discontinued or anything!

I was going to go with the N-flow, but everything I've seen online about installation says that it's "almost" a drop-in replacement, with tabs you have to bend/turn backwards/what not. So I figured if the AWR one is good enough for Mazda competition, then it is good enough for my purposes since the car is going to remain mostly at stock power levels (okay, slight power bumps due to downpipe and possible RB catback) and isn't going to be tracked.

My only concern from reading old threads is that maybe the "wings" on the Mazdacomp don't have appropriate cutouts to allow for the AC lines, but I think that that was fixed in later revisions.

 

I just bought an FD that had an aftermarket radiator of outstanding quality, with very pretty welds. While impressed with it, I was scratching my head about its origins. From this thread I realize that it is one of these original Mazdacomp radiators.

 

Just an FYI for those that dont know, the FD radiator is designed to be removed and installed from the underside of the car. Installing from the top will result in bent or broken AC lines.

 

Interesting. I removed my OE radiator and installed my Fluidyne from the top (after removing the IC, air box and cooling fans) without any trouble.

To the OP, if you can find one, a Fluidyne is another good choice IMO. I did no mods installing mine, just removed the original and installed the new one. My Blitz SMIC fits snugly up against the fan shroud, no doubt due to the thicker core but it fits without modification. My car's temps are good, 86-90 even in hot weather.