The Great Radiator Debate- What is really needed?
 

Well, Friday night I had an incident only to find my nice PWR radiator shit the bed. Had it dunked and found 3/4 various holes in the core. Guy at the shop claimed it to be corrosion/electrolisis related and it can't be fixed. Cool. $500 radiator is now worthless scrap.

Anyway, I snagged a stocker to hold me over until I get something that will cope with the heat.

Here are my choices and thoughts-

Koyo 55mm- $345 Beefy. Holds a good bit more water. I understand that thicker is not better and understand that as air passes deeper into the core, less heat is removed...at least in theory (I have not seen any factual data on this). Will fit perfectly on all the mounting surfaces but will need to space or bend the a/c condensor a little bit. Won't have to worry about defects from the factory. Worried about upper radiator hose contacting charge pipe...

Koyo 37mm -$299 Good flow, lighter weight (less fluid weight), perfect fitment (55mm has known issues for having property disputes with the a/c system). Costs about $50 less than the 55mm. Don't have to worry about build quaility.

Flyin' Miata crossflow- Most expensive at $500. Big core and longer tubes compared to standard radiators. Needs $16 upper radiator hose.

BEGi cross flow 38mm- Second most expensive opton at $465. Like FM, the longer fins allow more heat to be shed. Will need to find a upper hose that works.

Ebay/generic radiators- Worries: poor fitment, leaks. The last thing I want to do is find a leak and have to wait for a new radiator. I also don't care to have to tinker with making the fans fit. But they are much less on cost...half. I can get one for $200 shipped with fans and a shroud.


Now, I have an old 2/3 Cobra fan/shroud kit. Unfortunately the poly. shroud has degraded and cracked up, so I'd like the replace it. I'd like to get the FM shroud for $75 or I could get a generic ebay rad. with the fans and shroud and just use my fans....or at least hope that they'll fit on the shroud. I'm really leaning toward a KOYO unit, but torn between the 55 and 37 sizing.


Thoughts?

For the record- I have a reroute on the car that will be coming off when I replace the radiator.

Inb4 savington shamelessly plugging the never-in-stock TSE quadruplecrossflow rad:giggle:

It's not shameless. As a condition of his sponsorship, Sav is required to perform certain services for those of us on the staff which, outside of the Miata community, would be considered to be of a most shameful and degrading nature. :giggle:

Doppel, might I ask why you plan to pull the reroute?

I use a CST dual core and have been for years. It works, but I would have done the TSE rad if it were available at the time. Why not? If you're tracking the car, buy the best part for a touch more money.

What usage and mods?

I'm using an ebay special ~55mm and it's been great. Perfect fit even with stock fans and AC. Although the name that I got doesn't seem to be around any more and it's of much better quality than the pics of the ones available now.

I run a reroute as well but never have heat issues with my set up and the inlet air must go through the ~4" ic and condenser before hitting the rad.

I was kind of hoping you'd do something with the plugging part. Oh well;)

TSE shows the NB rads in stock....but at $489. The TSE raises some questions and I'd like to see a picture of the back of it where the fans mount. With the product description, it seems like I wouldn't need to run two fans on the back, so I wonder if one of the 11" SPAL fans I have would be enough (I could mount the other one to the a/c condensor to help keep it from heat soaking), but mounting the one SPAL looks like I'd need to make my own shroud. It would also require a special upper rad. hose to reach the front water neck on the engine (Sav...I'm looking at you to answer these concerns).


Removing reroute because my car is a 2002. Put reroute on before discovering the Mazda changed the headgasket design. Reroute nulls the revised headgasket...been meaning to pull the reroute off.

Car is a daily, do autoX and the occasional track event. It gets hot here in the south too. I'm not all too bothered by eGay specials, but I'm worried about fitment. I also did a search on here and found a few cases of people getting new ones and having leaks...do not want. I'm really leaning toward the KOYO 37mm, a new FM shroud and reusing me SPAL fans. I've even thought about mounting a pusher fan or two on the a/c condensor to help move more air across the three heat exchangers because in the summer, the a/c condensor gets heat soaked and my a/c turns into more of a heater.

Also, I lean toward the 37mm because the PWR was 37mm and the upper rad. hose was a tight fit past the charge pipe and I think a 55mm will force the two hoses into a property dispute. It would seem that I could trim a bit off the charge pipe and the rad. hose to make more room if need be, but I'm not 100% sure.

Here you can see what I'm talking about room between the charge pipe and rad. hose (old pic)

https://www.miataturbo.net/attachmen...ine=1323641017

The FM crossflow + FM shroud w/big spal fans will clear with the AC condenser and radiator leaned back with a 1/2" spacer on the AC condenser mounts. The radiator hose and TB charge hose should clear fine; I trimmed about 3/4" off of the radiator side of my hose due to the leanback. I'll post a picture later.

You have slimline fans, which are much less deep than the big spals FM uses in their airflow kit, so you won't have any issues there. They use the 3010.2029 and 3010.1522 if you want to check mounting bolt patterns to see if your current fans will bolt up to their shroud.

Their shroud is a nice piece of work, btw. I was going to make my own out of polycarbonate but after sourcing materials it was only about $40 more to go with theirs, and what I would have made would not have been anywhere near the quality of theirs.

pictures
 

From front and passenger side of radiator.

Ah, I understand. Can't really keep track of what year everyone's car is.

I wonder how the FM and the TSE compare. Since FM's is a single pass and TSE's is a 3-pass. If I decide to spend that much, it'll be a tough chouce. FM has the shroud- for an extra $75, but TSEs seems like that wouldn't be needed, just put one fan on the cooling side (I'd likely mount the a/c fan directly on the condensor). Can FMs upper rad. hose be used on the TSE? It would be nice if FM listed the core thickness of theirs.

I'll measure my FM core in the morning for ya. I've had no fit issues at all. Just put it in a few months ago, barely drive the car due to other engine issues, and it's been chilly when I do. Therefor I can't vouch for it's greatness for track or heat yet. I've got the radiator, their fans, and shroud. Shroud is spaced as far as the spacers will go and I used their upper hose as well. Did have to trim the shroud 1/8in or so around where the upper hose goes on the rad. The shroud was so close I almost couldn't get the hose clamp on.

So a quick measure of the core from the outside. Total thickness is 2in and after subtracting the core stand off I came up with 1.2in core. I will say their shroud is quite well made and pretty sure the fans could cool a house. I do get a little bit of RPM drop when they come on. Was a little scary at first with the tiny battery in the car and the D51r Optima battery makes it minimal.
Here is the gap between the hose and the piping. Mine is a bit bigger than with the condensor in. I tilted my radaiator forward to make getting around in the bay easier and not have the huge gap taking the condensor out made. The spot that I had to trim is right at the bolt where the hose meets the upper rad fitting.
https://www.miataturbo.net/attachmen...ine=1323659479

Yes I know I need to do some rad shrouding and ducting

I hate to say it but it sounds like you don't need what TSE's radiator is capable of. I'd say Mishimoto. I've had zero issues.

And is there no way to get a warranty claim on yours? Or is it fairly old?

FM did a bunch of testing with different radiators and a few designs they had before coming up with their current one. This is third word knowledge and I've not used one for myself. I have a PRC unit with a huge Taurus fan behind it. Keeps the engine right around 190 even when its 100+ out with the ac on full blast. With the NA's you gain a bunch of engine bay room, but the nb doesn't gain so much.

NB cores are in stock. NA cores are being redesigned and we'll hopefully have them out by February.

I ran with a shroud and two 10" Spals on my 2" CSF for quite a while. The car never stayed cool on track, even at only 200whp. If shrouds worked, we'd sell them.

What works is airflow management - you need to get fresh air to the radiator. The black car breathes through a duct opening that's maybe 4" tall and 24" long (the top duct in my signature picture), but because it's not blocked by an intercooler it works.

I have a HUGE 14" curved-blade Spal on the back of the radiator in the black car. With the fan on in 100*F heat, it runs ~210*F coolant temps. With the fan off, it runs 215*F temps.

The upper rad hose isn't hard - just grab a flexy hose from NAPA.

Crappy pic of the outlet vs. throttle body. The radiator is inherently set up for reroute-equipped cars, so you may have to be a little creative.

https://www.miataturbo.net/attachmen...ine=1323665014

The FM crossflow has a 32mm core thickness: http://www.mazda-speed.com/forum2/in...html#msg232263

From the pictures, it looks to me that FM's hose will fit the TSE radiator for a non-reroute car.

I agree with Savington that the airflow managment is the most important part of keeping these cars cool. Also I belive your reroute is actually making the car hotter than it would be without it due to it being an 01+ car.

Charles- Thanks for the link. That was helpful. I was thinking that the FM hose might work as well.

Sav- Thanks for making me want to spend more than I was planning :giggle:
Nice to know you guys looked into the shrouds. Since I don't have a seperate duct to get fresh air to just the radiator and I have a a/c condensor, do you think that will have a large impact? I think putting a pusher fan on the a/c condensor would halp with airflow across the three heatexchangers (and because there is no provision on the TSE unit for the a/c fan). What are your thoughts on that? Thanks for the pics, there is a lot more room than I thought there would be with the thickness of the TSE radiator.