ITT you will post the most outrageous radiators
 

I have never been able to keep my car cool in 100 degree weather. I've got a pair of Spal 11" straight-blades, custom shroud, vented hood, coolant reroute, and it still runs 240-250 degrees on a warm day after 2 laps. I'm starting to think I simply need either more efficiency, or more volume in the radiator, especially since I'm about to add 150whp.

So let's get crazy. Parallel v-mounted radiators. Ron Davis whatevers. I don't care as long as we haven't seen it before.

What about a dual core, crossflow, double or triple pass PRC radiator? They're $225 and circle track tested ;) . I picked one because the turbo and v8 swapped Z car guys run them w/o issue on track. Typical off the shelf units are ~$225, but they will build what you want.
Aluminum Racing Radiators, Oil Coolers, Reservoirs, Cooling Components, Wilwood Brakes, Tools, Goodridge Fittings
http://www.circletracksupply.com/ima..._universal.jpg

Whats your current radiator? What kind of water/coolant ratio do you use? FM's description (Flyin' Miata : Engine/Drivetrain : Cooling : 1990-97 FM aluminum race radiator and cap) says that beyond a certain point thicker doesn't help. Most of our godspeed or mishimoto radiators are 2", even spec miata koyo radiators are only 2 1/8".

If you want to have the best of the best radiator, you'll buy this one:
Springfield Dyno*Spec Miata Radiator*-*SafeRacer Sounds pretty damn impressive to me, who knows if it'll work. I'd say route the heater core to the radiator, and use that as some backup cooling, but you've ripped that out, haven't you?

As long as my turbo setup works reliably, and it's over 80 degrees, I've always had cooling issues as well. I'll be interested to see what people's solutions are that don't involve spending $600 on a radiator.

My boring old Koyo 52mm does pretty well. Scored from patsMX5 for like 150 shipped.:loser:

advance your timming some and drop that pos intercooler man problem solved.

Why don't you give Evans Waterless a try?

Chris

I want their oil cooler.

Need more fins per inch, smaller diameter tubes, and more of them. It is all about surface area. More pieces means more money, but it will work. That's why the VW Scirocco radiators were popular for domestic hot rodders. They were very small and light, but had a very high fin and tube density and therefore tremendous cooling capacity for their size.
Strong enough for a big block, made for a VW.

there;s a pretty good example on the front page!

I've seen the fan shrouding argued and talked about so much.

I think it makes sense for a street car to make the fans work their best. But I feel that it is a huge disruption of flow on a high speed car. I have NOTHING technical to back this with... just my opinion.

But since you've already seen my setup on here... I won't post it. 88deg IATs on an 83deg day. Coolant warms and never budges, I don't even ever have the fans kick on just driving around and in traffic. Seems to work for me.

+1

Pull the shrouding off, make a mount for the fans that takes up the least possible surface area, move the oil cooler and intercooler, and do the ducting in front of the radiator.

Is your exhaust free flowing? I have seen clogged up exhaust cause over heating issues.

he has a turn down tip....thats it.

sav, you need air directors. get 50 toilet paper tubes and bundle them together and shove them into your nose.

And add 50 CPU heat sink fans to each one.

you fucking douche-bag ------s!!! How many key-strokes did I waste trying to convince you of this and every time you stick with "use a shroud, plug my dirt-pipe"? Do not ever argue with me again or you'll have to pick your dignity off the floor when I beat your ass in front of your mother.

edit: thought splittime was savington.

2-pass or 3-pass radiators in theory are superior to standard 1-pass radiators. I don't know anyone who makes off the shelf ones for the miata.

Read this
Welcome to U.S. Radiator
The theory is sound IMO. A 2 or 3 pass radiator will make the coolant see the equivalent of a very long skinny radiator. The velocity of the coolant in the individual tubes will be higher, increasing turbulence, encouraging the transfer of heat from the coolant to the aluminum, by breaking up any insulative "film" of cold coolant sitting near the aluminum.

However you need to find out if you have lack of airflow (i.e. lack of heat transfer from the radiator to the air) or lack of heat transfer from the coolant to the radiator.

What I did to solve my overheating problem was to place thermocouples and look at air temp entering and leaving the radiator, and coolant temps entering and leaving the radiator. I determined my problem was lack of airflow, and not poor transfer of heat out from the coolant. (air temp drops were huge, coolant temp drops were small) Switching from my AVO intercooler to the TDR, solved it, by allowing way more airflow through to the radiator:

See pics of airflow test:
https://www.miataturbo.net/forum/t11679/

Those fucking turn down tips make the exhaust a lot louder in the car. Ask me how I know...

Jason, write me a dissertation on Evans coolant so I can ignore it and do something useless instead :makeout:

I'm not convinced Evans overall helps cooling even though I have it and use it - in theory it helps prevent ping despite higher coolant temps. I added it at the time I changed to GTX pistons and 8.4 overall c/r so I didn't do 1 change at a time. What I do notice is that I don't get the "Mr. Coffee" sounds at shutdown, and I run a 5 psi cap, which means the propensity for leaks is a lot lower. I don't recall having a leak with Evans despite old hoses lol.

I've only seen one article with a seemingly proper test, on a modded Honduh, and they claim they indeed got more advance before ping on a dyno on a hot day; they'd turned down the fans or something to get the coolant hot. I've never seen another article corroborate this. GRM had one article - it was part of a 5.0 Mustang buildup. They described it, but no followups. I posted on the site to ask how it did and they said "it seemed to work, but we sold the car, and as far as we know it's still fine". This seeming lack of proper testing on Evans coolant is pretty puzzling. Their website sucks too - it looks like it hasn't been updated in years. If I were them I'd get magazines to test their shit.

Using Evans and a reverse flow electric pump, seems to be synergistic. The complexity however .... BTW Autospeed.com got threatened with a lawsuit by the Davies Craig electric pump guys. Rumor is that they tested their "more hp" claims, saw none, then DC shut them up. Stupid, because part of the test could have been to see if the flow was adequate in a typical setup... and then you have the potential to run reverse flow. Who cares about 2 hp if the reverse flow allows 2 psi more boost at MBT.

I think 240*F coolant temps are OK, IF you don't have ping. But if you see 240*F now, Evans will raise that a bit. Not sure if that would be OK despite lack of ping.

The problem with Evans vs water are:
- higher viscosity (however the new stuff NPG-R is significantly better than the old stuff)
- lower specific heat

The lack of spot boiling is Evans big advantage. In theory it's possible this offsets the above such that overall cooling is improved (setting aside the ping issue), but whether it is true in the real world, I don't know.

To test if a running fan is an impediment at say, 70 mph, here's an easy test for those with easy to remove fans.

Cruise at 70 mph on a hot day with both fans on, read coolant temps.
Pull over somewhere, remove 1 fan, repeat.

Why are high coolant temps bad, aside from localized boiling? Can I feasibly run 275 degree coolant temps using Evans?

My friend uses that thick springfield racing radiator on his 460hp miata that sees only tracktime and he doesnt overheat anymore.

Who is your friend? Is he actually fast?

Ru Paul...the dude can drive.

C'mon man. Everybody knows Ru Paul only drags.

^^ Grooooooaaaannnnnn :)

You may ping despite lack of localized boiling, then you have the materials - the piston may expand too much, the oil seals may suffer, the exhaust valves ... I saw a testimonial wherein they lost a fan but pressed on despite very high temps. Upon teardown the only damage was to the oil seals.

There also seem to be testimonials from Harley and other big bikes about Evans, IIRC about cooling improvements in stop and go traffic. Another one I recall is from off roaders. Notice these are low speed - I don't know if this is relevant.

@Savington: what exact setup do you run now?
Radiator?
100% pure water? Water wetter?
Reroute, how?
Heater core?
Thermostat?
IC sealed against radiator?

Yea hes pretty fast. Well fast enough to be able to run down a 600hp corvette at road atl. and roebling. I'll get his shop number so you could call him if you want. He'll talk aero and cooling efficiency all day. His dual oil cooler setup is interesting too. This is his car (it was bright that day)
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Very interesting. I would have thought that even with a 40 or 50 degree increase in coolant temps, the expansion rates of the pistons and such would depend far more on EGTs and intake air temps.

can I get more pics of that oil cooler set-up?

Where did the duct come from?

The setup is just two NACA ducts with piping inbetween them and a plastic shroud ziptied onto tiny oil coolers. Its pretty straightforward. If I had pics at the moment I would post them

I'm not 100% certain about this, I'm speculating.

link? That looks somewhat acceptable.

I already like that guy. Savington just sent me a PM for some advice on attracting another man, so hopefully those two can hook-up...if you're friend is a power-top of course.

Savington: so
Savington: ru paul
Savington: if that's his name
Savington: tell me about him
Savington: cause his shit looks fast
Savington: or it looks like it could be fast
Savington: except he's on R888s, lol

:borninthe90's:

Haha thats hilarious. Surprisingly he has no pics online since the car was just recently built like that. He easily has 50k into that car including the base price. The only reason hes using r888s is because if he would use anything better they would bump the car up a class in the series he races in. Atleast they're 245s on good rotas. I wish he were a member. The shop specializes in miatas so im surprised he doesnt have an account on here. But if anyone really wanted to talk to him, i'll talk to him tomorrow and see if hes alright with me giving his number to anyone in need of advice. His name isnt Ru Paul though. Next time I catch it on the lift when im there i'll snap as many pics as I can get

Sam, that car is the sex.

Michael

+1!

O the epic pawnage.

rumor has it that this shop was famous for building fast cars, but more famous for getting crushed by fast drivers. lol

If I were beaten, I'd want it to be by a faster driver, not faster equipment.

$50k? That's frightening. The car does look good, but those tires look like 70 series side walls, lots of ride height, and that diffuser would look right if it was tucked up into the car... maybe that's why the car is sitting high?

What series is he running? Seems odd that moving from one DOT race radial to another would make for a class change.

street class vs. race class - time trails yo.

OK, I thought the R888 was the new Toyo R1 "replacement" tire for spec miata (which I ran on recently).

Speaking of turbo Miatas and time trials. - anybody remember the AIM Tuning stock motor turbo'd Miata? They posted here, way back. They were stomping a lot of these super cars- and were running a modified class. I don't recall any major issues with the car, like overheating.

that front end is so ideal it hurts.

And where's all the extra holes in the nose, radical Vmount, or extractors in the hood? :giggle:

Jason,
What kind are temps are you seeing with the Evans; track, autoX, and DD?
Are you running the NPG-R or the older stuff?
Any long term durability concerns?

Isn't the main problem with overheating the steam pockets (nucleation point?) and that when these occur the temperature differential is what is mainly causing engine damage? As long as the oil temps are kept in check, wouldn't higher coolant temperatures be fine, within a certain degree?

Another reason pushing me towards the EVANs, Rotax requires it for some of their aircraft engines.
Feeding your Rotax 4-stroke Aircraft Engine | Rotax fuel, Rotax octane, Rotax oil, coolant, waterless

Manufacturer Info:
http://www.aircraftspruce.com/catalo...%20Coolant.pdf

Chris

EDIT: Also, wouldn't this be the cheapest/easiest mod for overheating? EVAN's < extractor hood, reroute, double pass crazy sized radiators

Interesting find!

Well if it's true that you can run a lot hotter safely with Evans then yes it may solve Sav's overheating issues - assuming his oil temps stay <250*F.

I think a fair test is for him to dyno his car with det cans while increasing the coolant temps all the way to 260*F and monitoring the CHT, knock, and HP. If HP starts to drop sharply at a certain colant and/or head temperature, that would be a danger sign.

Ideally Sav will add a CHT gauge before he converts to Evans.

I use NPG+
I have no long term durability concerns. I get to 110*C on a hottish day at the track
I put it in before NPG-R came out. NPG-R is better in all respects except they recommend changing it out every year or 2.

Haha where did you hear that. They're usually the fast drivers in underpowered miatas outcornering everyone, but yeah they run mostly highspeed tracks which most miatas that cant go over 130 easily are usually beat.

This is true

I've effectively talked myself out of doing that to my car for years.