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

 

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.

 

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 ******* 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 *** 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 ******* 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

 

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 ****.

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.