I recently found out that Stillen has an aftermarket aluminum radiator available for our car and as far as I know, no one has ever mentioned it. I have had great experiences in the past with Stillen products it's probably a good product. So I figured a thread with all of the available radiators in it might be helpful.

Edited 10/17/14

1. Mizu Racing Radiator: I have it and fitment is perfect. No longer sold new but mine is still working just fine.
2. BHR/Griffin Radiatlor: Most reviews are great from everything I have read. But we did have one local guy who significant fitment issues. I am not sure of that was resolved by BHR with Griffin or not. http://blackhaloracing.com/?page_id=...&product_id=18
3. Mazmart/Ron Davis: Fitment is known to be perfect and performance as well. I have this radiator waiting to go into Hoss-05's car and I can say the build quality is excellent. Ron Davis also offers other variants (dual core IIRC) for the RX-8 thru Mazda Motorsports http://www.mazmart.com/ItemDetail.aspx?id=257
4. Koyo rad: Some fitment issues have been noted and many have stated the performance is lacking even when compared to the stock calsonic radiator (which is pretty damn good). Some have stated both fitment and performance have improved. http://thmotorsports.com/koyo/koyo_r...5/i-35589.aspx
5. Knightsports/Koyo: Great fitment and performance according to nycgps. http://www.knightsports.co.jp/
6. Greddy: Not much on it. http://www.jmautoracing.com/20042010...r-p-51426.html
7. Mishimoto: Known fitment issues, not sure how it performs. Mishimoto did chime here in a thread and state that the fitment issues were be fixed. Not sure if that ever happened or not.http://thmotorsports.com/mishimoto/m.../i-253144.aspx
8. BWR: Never heard of it or anyone who has used it. http://assaultech.com/blackworks_rac.../i-397367.aspx
9. PWR: Top notch product used by many race teams so i am sure it fits and performs well but that is juts my guess. http://www.vividracing.com/catalog/a...04-p-6136.html
10. AWR: http://store.awrracing.com/radiator-...petition-8501/
11. CSF: http://www.redline360.com/csf-radiator-mazda-rx8-3164

I think that is it, if you guys know of any I forgot, please let me know.

 

When my radiator broke in December of 2009, I initially bought the Koyo and in my experience the fitment of the specific radiator was terrible: location of the fan mounts were not aligned, bottom hangers were offset and didn't fit the rubber bushings, and there weren't any top hangers. I returned it and ordered Mishimoto instead. The only problem I had with Mishimoto's radiator is that I had made adjustments on the top hanger, it was angled differently. In addition, both are thicker than the OEM Calsonic radiator so the coolant reservoir and the rod for the hood fits a bit snug.

I can't offer much of performance, but I went through two >110°F Summers and driven with it for more than 40,000 miles without any issues. However, I recently noticed loss of fluid due to a broken coolant seal/freeze plug(white smoke at start up and sweet smell out of my exhaust); I can't say it's because of the Mishimoto radiator, my original engine racked up a pretty good mileage, as well.

 

Mazda Motorsports sells a competition Ron Davis radiator that is different than the Mazmart one. Pretty sure it is bigger and requires some custom fitment work, but they swear by it. No experience myself.

 

I forgot about that one. For that one you have to be part of the Mazda Motorsports program right? I also heard C&R Racing sold one too but I searched for info on it and could not find it.

 

I have the Ron Davis Motorsports rad...it is a huge core that is dual pass....

It really won't work with an OEM setup though.......it doesn't come with mounting tabs for the A/C condenser and the fan. There is another similar Ron Davis one that I have seen which is the same core...with the mounts and everything so it ill fit OEM that will be out soon I think

The C&R racing rad is a beast too...but has similar problems the the Motorsports rad..they are made for a racecar...so custom setyp is needed

Also the radiator hose position is different than stock...so tweeking the rad hoses is needed

 

Cool, I had heard C&R made one but I guess it would be for track only use. I bet it is expensive as well.

 

You beat me to it man, but as far as I know C&R does not make a radiator for the RX8. If they did, it would definitely be quite expensive and overkill for a non track car. On another note, a friend of mine has a Mishimoto radiator for his RX8 and he couldnt be more pleased with his purchase.

 

I think with the cheaper models fitment can be an issue but not with every unit. I think it's just poor QC. My Mizu fits perfect but I can't speak for anyone else as it is pretty new.

 

How about CSF RADIATORS???

 

Never heard of them.

 

it's just an OE replacement plastic end tanks and all, not even worth mentioning.


.

 

9krpmrx8, i was thinking about ordering the Mizu Racing Radiator. how was your temps?

 

It's a great radiator, no problems at all. I am turbocharged now with a brand new motor. But lately it has been cold so the real test will be in a couple of months.

 

I dont have fitment issue with the koyo rad. As for performanace i think most of the koyo owners were earlier adopters and so most of them never transfer the foam over to the new rad. which resulted in garbage performance. I still have my koyo rad so i might swap it back in next summer just to test it. Hope i will have time to do that

I have been using knight sports rad made by koyo for quite a while. I would say im quite happy with its performance. Almost double the size of stock rad. Comes with everything u need for install. Even comes with new foam foam for u to stick on. The lower tube mounts different but it comes with extra tube.

 

Lol, you are turbo but not tuned, so neither boosted yet nor running hard

Didn't see this one listed

http://store.awrracing.com/radiator-...petition-8501/

 

I know, that's a nice one.

 

Not everyone may be aware of your epic adventure thread

 

Knight sports is double the size? Huh? You dont mean the face front do you? Face front size is one of the most important characteristics to think about when it comes to cooling capacity.
OD

 

I have this one, fitment is perfect as far as i can tell, its dual pass ron davis core. installed for about 3-4 month already, given its not really summer temps right now my temperature gauge has been pinned at 70-80c during normal driving and a little above 80c on spirited hill climbs, haven't been to track with it yet but will come back with numbers afterwards,

the plastic nozzle on the stock radiator broke on me after a track day and i decided to do a proper upgrade.

i believe that's the same one, or at least that's what tony said on the phone when i called him

 

I'm pretty sure the AWR one is the same as the one from Mazda Motorsports, price is about the same and they both share the same -8501 part number

 

Stillen has discontinued their RX8 racing radiator that they got from CSF, Mizu is back ordered 30-90 days so if you want one buy in advance as its going to take a god awful long time for it to show up and believe me nobody has any in stock I checked went through four different people who said they had it and then turned out they didn't it's been a waste of my time

 

I have a koyo rad, no fitment issues. I superglued some new foam on and it seems to be keeping the car cool. It is running @179-181 under normal driving conditions in 80*F.. I will be reporting back in a month or so when temps run up toward 100*F and higher.

 

Mishimoto just redesigned their radiator. It has become extremely popular if you guys are interested we have some in stock.

 

differences?

 

Fitment was off on the old style.