Yeah, both fans on at 195 off at 190

Volt fans are rated 1800CFM each, so 3600CFM total, and being PWM can set speeds to be quiet when just maintaining temp, and hurricane when really needing to shed heat.

Factory ducting/undertrays all in place, foam strips all in good condition as well.

Yeah, I could possibly get a custom radiator made up at that price as well, but not sure I want to deal with that headache.
My worry is, I still have AC (not getting rid of it either) as well as Power Steering. and they mention that rad isn't intended for AC, but don't mention Power Steering at all. I assume being Spec Miata guys they didn't even think about Power steering lines/cooler.

 

Are you on the stock radiator right now? There are plenty of options that would work with AC and PS, are cheaper, and probably be effective enough as well.

 

Yeah, still on stock everything coolingwise.

Really, if I'm buying a Radiator, I want to buy one that will hold up to any future plans for this thing.
My theory is ALWAYS, overdo cooling and fueling. So if I'm doing it, I want to be able to cool ~350hp reliably.

 

After looking closer at my car, comparing with the images on the Advance Autosports page (they really don't do well there, wish they had dimensions as well) I think I found why they say nothing about the PS, but mention it's not intended for AC cars.
What I was thinking was the PS line at a glance, was the High side AC line, running under the rad.
The return from condenser also runs under the rad on the passenger side.

I don't particularly want to have to customize the AC system in this car, so maybe the best option now would be to either get a 100% custom rad ordered (gonna send out a few forms for quote), or go with the SM crossflow, and modify it for double pass. Still on the fence.

 

I know both Flyin Miata and Supermiata extensively tested radiators and both came up with the same answer, crossflow single pass. I'd get one of those, duct it very well, and be done with it. I don't remember the details, just that I read about it a few times over the years, and double pass as good as it sounds didn't perform as well in a miata. Something about diminishing returns of cooling with double pass, slowing down the flow, actually making it cool worse. This isn't gospel here, so do your own research, but that's what I remember. Supermiata builds some of the highest horsepower record breaking track miatas on the west coast, races them in the desert, and developed their radiator to handle that. And they are on this forum, easy to communicate with, etc. so that's always where my money goes.

I just replaced my mishimoto alum radiator with the SM unit and the difference was huge. I did some serious revamping of the front cooling stack, including bumper bar delete, and overkill ducting (see my thread, this all happened this spring), and my CLT'S have been comically low. Where I'd get to 225* on lower boost I'm seeing barely above thermostat (185*) on higher boost at my local track.

Anyways interested to see what you come up with, the car is beautiful and glad to see you are racing it!

 

My reasoning for double pass is slightly less about it's improvement over the single pass, and more about the ease of plumbing.
In the future I'm planning a reroute here (testing all the options, reroute with later HG, reroute with earlier HG, no reroute, etc). and the inlet on the drivers side is a much easier way to route the reroute long term.
Short term, I avoid the annoyance of the interference/tight fittment between the intake tube and the rad inlet.

Just reviewed your build thread, and yeah, that ducting looks very well done.
Currently i'm on 100% OE ducting in good condition. Yes it could be made better, but if I"m in there doing custom ducting... might as well dump a better rad in as well. and if I'm doing that... might as well dump one in I want for long term.

 

OK, Gathered quite a bit more information to make a decision.

FM crossflow core 36mm thick, single "O" tube koyorad brand. Rad Cap on top of the drivers side tank. $479 (plus $20 for upper mount to clear rad cap)
SM crossflow core 32mm thick, double/"B" tube. rad cap on extension on drivers side tank. $394, works with stock mounts
Custom, all wanted to use a "standard" core and build tanks on it, but none really fit the dimensions of the Miata. And those that were willing to do a "custom" core dimension were astronomical ($1200+)

Strictly speaking to convert to Double Pass the work would be about the same for each.
But realistically speaking to convert the FM, I'd move the cap to the Passenger side instead of leaving it on the drivers side. Requiring more customization etc. where with the SM it'd be cut off the inlet, cut off the rad cap extension, swap them. then cut/weld in a center separator plate.

Slightly narrower core, slightly more restriction in the narrower core, less work to modify, and $105 cheaper, yup. going with the SM

And measured up the Volt fans (have a Volt as the daily, makes this task easy) and they'll take a little modification, but will fit very nicely.

So... guess all I have to do now is click the "empty my bank account" button.

 

If you want to buy 2 and send one over to me that would be great

Do you think you'll try it stock first to see how it performs and then convert it over to double pass? I'd be interested to see the data on that if you end up doing it, especially with some of the Miata tuning houses reporting that they didn't perform as well.

See you in Montana!

 

Sure, no worries. Just expect the $800 special delivery charge


I won't be trying it in the OE configuration first. I don't want to have to try and weld on Coolant Contaminated aluminum. not to mention fight the plumbing (the reason I'm going double pass in the first place.)
Sure, I miss out on some data that might could be useful, but... not worth the effort to me just making it harder to get where I want to be in the end.

UNLESS, you want to buy this one off me for what I pay for the next one, after getting the data. (IE, I install this one OE, get data from it, buy another to modify, and sell you this one for whatever the next one cost me)

 

Curious about the same. Please do this (for science)!

Edit: oops too slow.

 

Tempting...Might be more work than it's worth, but I'll think about it.

 

Got a nice box yesterday,


Packaged VERY nicely, I'm quite happy with this.




Even comes with coroplast, so you can fix your ducting as well.


So, first thing you do when you get a new radiator? Use it's own box to protect it.



Inspect all the holes.




Then promptly take a sawzall to it.



then with fresh flappydisk on the grinder, clean up the fittings and make them fit nice.








to make it crossflow, one tank needs to be split in 2, forcing the fluid to the opposite side, where it can flow down and back across again.
Ideally it'd be "perfect" you'd have the same tube counts above and below... but I have 41 tubes in this rad.
So I opted to split with 20 above 21 below.


Marked it out, and started hacking


had these weld coupons in the shop, and it's a perfect piece to use.

and after a TON of fettling to get it to fit tight in the C channel where I can't weld it, here's the blockoff plate.

here you can see the "B" tubes, as well as how I placed the spacer plate between tubes.



Fits nicely.

and with a quick brush with a new stainless steel brush, as well as wipedown with acetone, I burn it in. It's now a Double Pass (sorry @SimBa too late to test with cross vs double)


So, probably good idea to test whether it leaks.... and of COURSE it does.


And I figured you'd all love to see how professional I do things around here. only the best for the low mile MSM.


A quick pass with the buzz machine, and it holds now.


At least the warranty is still good, right?

 

Technically not too late, just buy another one! Interested to see how this works for you, keep us updated.

 

Giving me Technology Connections vibes.

"And through the Magic of Buying Two of them...."

 

I mean, if/when I buy that radiator I could have it shipped to you, you could swap it out, do some testing and then ship it to me. It would be a bit obnoxious, but not too far fetched if someone was really curious about the data.

 

Bit of an update here.
Haven't worked on cooling at all since converting the radiator to Double pass.

Friend of mine discovered his seats don't actually fit his new car with the cage in it. so we swapped.
Looks very roomy without seats.


Mmmmhhh Carbon


Fit the car very nice.




then work sent me to England for 2 days. I spent more time traveling than working... what a waste.
Oh well,
Back late friday night, and attended the local autox the next morning, missing ~20hrs sleep for the week.
Course was not all that good, and I was off my game. (also thinking my yok's are heat cycled out), got edged out of first in XB by a few hundreths.
I noticed during the event that my speedo was spotty inoperable. one run it'd work fine, others would be stuck on 0.

Investigated that sunday, and found this.



After prying the gear off I discovered this polished ring on the sensor.


I believe I had the tolerances just a bit too tight on the gear, and getting the car hot over the last couple events the gear warped slightly on the collar that covers that ring.
With the warpage the gear was then rubbing the sensor generating more heat, warping more.
Evenually the force was too much for the teeth and they let go.
Then it cooled down because it wasn't spinning, and let the gear catch again.

printed up another with slightly wider tolerance on that sleeve, and she fits strait off the printer.
We'll see if this one has the same problem in the future. worst case I keep printing them, it's only a 5min swap job once the car is in the air.

 

I thought those seats looked different. Drop any weight over the old ones? TBF can't quite remember what was in there previously.

 

Had some hacked up kirkeys in there. at ~14lbs/each (11.7lbs without cover/padding)
Where the QRT-C's are 12lbs/each (9.5lbs if I stripped the cover/padding)

So, yes a bit of weight savings. But mostly MUCH more comfortable in every way.
Only slight downside is the sparco doesn't support the thigh as much as the Kirkey did. And this is such a small gripe it's not really worth mentioning.

 

I'll never miss a chance to advocate for taking the time to make a seat fit you. Not sure how the QRT-C differs from the QRT-R I have in my car, but it looks like the same thing made out of fancy pants carbon and maybe slightly narrower at the shoulder wings. I needed a bit more thigh support, and I added more foam in the lumbar and center of the upper back area. It felt like my shoulders were pinched forward before I did this, the seat had me curled up almost. Confor foam from Aircraft Spruce and a steak knife go a long way towards taking a seat from "this sucks" to 8 hour drive... okay. I'll never call that long of a drive held in one position truly comfortable.

 

Well, back to the cooling situation.

As I mentioned before, I'm going with Volt fans.
New they are ~350, and the harness (or plugs for the fans) is another ~70.
That's a bit more than I really want to spend, but it's WAY less than any of FM's options.
I COULD go with RockAuto, aftermarket replacements. But they are around the same price as OEM, and not "spal" OEM fans.

BUT there's another option. enter Car-Part.com. It's a gamble, as someone may have replaced the fans in the past on the car they pull it from, but I'm willing to take that gamble.
A radiator fan there... $200. Sure, I can do half price.

And SURPRISE, it comes with a partial harness, and an Electric cooling pump. Amazing. And yes, OE Spal Fans.




I have a spare NB rad on the shelf. and just laying the fans on the rad... real close match









So, anyways, I started hacking.


I cut off the side mounts, the lower ~2" "shelf" section, as well as some cutouts for the inlet, outlet, and rad cap.







Now that's partially solved, How does the rad fit in the car?
well... it doesn't.
The condenser is definitely interfering with the rad.




So, how do we solve this? By mounting it backwards.



I was able to finagle the condenser to the other side of the mounts (weld nut side), as well as swap the bushing mount collars to the rear, and shoved some shorter bolts in.
Disaster averted.





I didn't get good pics of it, But I cut off all the fan mounts on the rad, and reused/relocated them to mount the Volt fans.



I sealed up gaps with some random weatherstripping and bolted the fans solid to the rad, stripped the wiring down to the fan only, and slapped it in the car.


I then started playing with the wiring.
Got a really janky test setup and tested ONE fan.

Holy crap.

Now I'm waiting on a breaker so I can wire this intelligently and not melt down the car.