Get a mishimoto or Koyo radiator. The stock radiator is rather lacking on the STi

 

^exactly

 

That looks like perfect operating temp... i am confused.

 

CNY_STI : Thank you for the suggestion :tup: I have checked it and it seems that it is one of the best rafiators.. BUT my STI is an auto (couldn't find a stick shift as the Sti is super rare here) so according to mishimoto website, I need to buy a transmission cooler kit as well. Will read more about it.

Linsanityfan : It seems that it's a well know fact :lol:

OEMplus : It's usually in the middle.. and the needle was even higher just before I took the photo.. It was at the line just below the red!

 

i'd be interested to see if evans waterless coolant works better in those conditions.

 

Koyo 2 row radiator is a good first upgrade.

Also consider installing an oil temp measuring system and logging on your AP the water temps. If you find oil temps stay high, consider a Killer B oil pan which gives you more oil to do the same work and this also keeps temps down but the best place to start is the Koyo 2 way radiator and take it from there.

 

Nail : Just did some reading about it.. look interesting..Thanks

Toivonen : Thank you for the info. My Sti is 100% stock and unfortunately there is no AP system for it in the market (EDM Sti) so I won't have a possibility to hook up an AP to check all data :crying:

Will look into the koyo but how about the mishimoto X line with fans kit!? I've heard that they both work great..

About the oil pan, I will need to read more about it

 

The fans are not really necessary but both the koyo and x-line have had good results from people here.

Since your area of the world is ~80s-90s for winter and ridiculous in the summer an oil cooler and possibly a power steering cooler would not hurt either.

 

Definitely upgrade the radiator. A Lower thermostat can help too, I'd imagine it's hot all year round there so shouldn't have a problem warming up the car. Painting the intercooler black will absorb less heat too, more so while stationary or in a stop and go movement such as street light to street light or in a traffic jam. Moving at higher speeds it works just like an unpainted intercooler.

 

Don't buy a thermostat:
The Truth Behind The Subaru EJ-Series Engines - Tech-Knowledge - Import Tuner Magazine

"Another falsified fact is using a lower-temp thermostat will make your motor run cooler in hot weather but in reality it will have zero effect on increasing your engine's cooling capability."
- Crawford Performance

Black Intercoolers are completely overrated, and potentially more harmful that helpful. Intercoolers cool via convection, not emissivity.
https://www.youtube.com/watch?v=z_mmmXTbLP0

If you want to lower your temperature, you need to increase the cooling capacity. The previously mentioned radiator and Killer-B oil pan will help increase that capacity. I haven't done enough research into oil coolers to make a recommendation on that.

I'll also throw this out there: Amazon.com: DEI 010393 Reflect-A-GOLD 24"x 24" Sheet: Automotive

Test: http://www.iwsti.com/forums/2-5-lit...-liter-litre-factory-motor/245621-diy-heat-managment-cobb-sf-intake-airbox.html

That isn't my first choice to solve your problem, but it will help decrease intake temperatures a bit if you cover your intake components and the intercooler (NOT THE FINS).

 

I've never seen my temp gauge fluctuate at all. All these option outlined are important but you should definitely make sure you're running a good synthetic oil that isn't prone to shearing down. Especially if you do any sort of track/HPDE events.

 

Yes a thermostat doesn't increase capacity, I said it "can help too" by allowing the engine to begin cooling sooner which is what a thermostat does.

The intercooler video was informative, he should post a real test though.

 

A black intercooler doesnt absorb as much heat???? what?

 

To the OP,

No car is built for 135 degree summers, this is not really a Subaru issue, the issue is present on any car in the world under those conditions. I lived in the desert for 13 years now(Tucson, AZ), it gets very hot here as well and we are in elevation and can only run 91oct gas so I can relate your history with my own experiences.

I am running a Cobb AP and my intake temp was reading 199 degrees as I was pulling to my garage, my water temp was at 210. In my opinion the oem radiator is perfectly fine, you are just running in a very hot environment.

I ran at the local dragstrip well over a dozen turbo cars in the summer here, all of them with stock radiator(4 Evos, 2 STI, 4 Eclipses, 1 WRX, VR4, 1 GTI, 1 GLI, BMW 335i) you name it and by the way, all of them running much more boost than factory. In summary, don't panic, what you are describing is totally normal to me. I will retain my stock radiator which is working very well for me. my .2c

 

I would like to add that if you have the money to blow I would suggest some high power fans and perhaps a vented hood with big openings. There are other alternate grills that offer bigger cooling areas with less restricted air flow.

 

Bestswat :
Thank you for the suggestions mate.. will look into it

STi_1212:
I do not track the car at all.. but almost aggressive daily driving All the oils and coolant are checked and replaced by the subaru service center here so I'm sure that they're feeding it what's recommended by the manufacturer. I guess it's just the weather here that really messing up the car hahaha

pocketdrummer :
GREAT ideas.. Will look into heat shielding some parts of the engine bay.. but can't do it to the air intake as I didn't upgrade the factory one.. I was thinking of going stage one next month but now I guess I need to postpone it to deal with the overheating problem.. Plus, my sti is an EDM so no Cobb AP for me :s and I need to search for a good tuner around here.

red2012STI :
As you said, no car was built for such weather.. I was just trying to DRIVE my car any way I would like to.. It just sucks to know that I will be stuck on I.Drive for another 3 months and can't get the power when I need it.
I'm willing to spend 1000$-2000$ for a cooling system that will beat that heat hahahaha

Was thinking of getting a Mishimoto X-line Radiator, Oil cooling system, and some heat shielding accessories first then go from there.. Oh and guages of course.. It's still 100% stock so I need at least gauges to monitor all temps.


By the way, last night it was 107F at 9pm... :tup:

 

If I remember correctly, the GR chassis has a smaller radiator than the GD chassis. I'm not sure about the VA chassis, though, so they may have improved the design.

As far as fans go, they will only help when the car is not in motion. If you're nearly overheating while you're driving, they won't help.

I suppose you could try a vented hood that draws air from the back of the radiator. Maybe even a radiator shroud. I'm not sure if you'd notice any difference, though.

 

If I remember correctly, the GR chassis has a smaller radiator than the GD chassis. I'm not sure about the VA chassis, though, so they may have improved the design.

VA has the exact same radiator as the GR/GV. OP, the simplest solution is to buy the Koyo Radiator and run something like 30/70 coolant to water ratio. That'll be more than enough to handle aggressive driving on the street. On track is a different story, but does not sound like you track. Good luck.

 

I am having some pretty serious cooling issues right now. 2015 sti, built block, big turbo, 27psi, etc. if I turn on the AC and just drive 65 mph, my oil temps goes to 250-260f and the water temp is 220-230f here in Houston with ambient at 101f.

I have to ride with the windows down, and can have my oil hover around 230f and the water right at 203f which isn't terrible, but not great either. The AC condenser is what's killing me.

Needless to say I'm going to try to do an oil cooling system that mounts where the tmic used to sit. 50,000btu/hr is what my calcs said I needed to remove to keep the temps at 220f with 100f ambient.

 

We are all this week in the 112-115degrees in the Tucson/Phoenix area and my car doesn't get as hot as your car. I have everything stock as far is radiator. I only saw a 199 intake temp and 212water temp peak the other day when I let the car sit in the sun at iddle for a few minutes but the temps go down once you start rolling. I don't know what could be causing your car to get so hot.

 

Quote from Killer B:
http://www.iwsti.com/forums/3114330-post9.html

And another:
http://www.iwsti.com/forums/3114388-post13.html

And MotoIQ:
Project Gen 3 Subaru STI: Keeping it Cool with Koyo

If you're looking at a larger capacity oil pan, you might as well look into this combo deal and get yourself a better oil pickup while you're at it.

3-Piece Pan, Pickup, & Baffle - Combo - Oiling Products

 

pocketdrummer :
These are some valuable info. Thanks a lot!! :tup:

About the vents: I sure will get some tickets and fines for that. The police here fine drivers for ANY visible mods on the car that-as they say- "change the original or stock shape".

LinsanityFan :

Heard and read a lot about Koyo and will really consider it BUT My subi is an automatic
That means that the transmission oil cooler is attached to the stock radiator.. once I change the radiator, I need to buy and install an aftermarket oil transmission cooler :s So now I need to read more about that haha

I have read an article called (High Performance subaru Builder's guide) by Jeff Zurschmeide that states: (It does make sense in my humble opinion):

With an aftermarket cooler, you can potentially keep your transmission oil too cool to do its job effectively. The in-radiator cooler keeps your oil warm enough to flow well, but not so hot that it loses its effectiveness.

hmmmm ... but I think the best first step now is to install as many gauges in the car (joking.. just few) and do extensive research on the effect of this weather on all liquids in the car..

I'm afraid that If I kept my car too cool then It will come to bite me in the winter when the temps are around 0c to 10c (32F-50F)..

That big of a change in temperatures between summer and winter here really take its tole on the cars...
But hey, 98oct fuel here is 0.35$..

 

I would consider a Ron Davis radiator or an LIC radiator which have a built-in oil cooler. You might need to fabricate some oil lines for your transmission to make use of the built in oil cooler.

http://www.iwsti.com/forums/showthread.php?t=278375

 

uschearak obviously has a fmic (and wants to put an oil cooler where the tmic used to be). FMIC + hood scoop hurts cooling, even worse if you also ditched the stock under tray. The aftermarket exhaust + big turbo + increased cylinder pressure + AC will also generate a lot of heat.

Sad thing is these engines don't like the heat in stock form. Living in PHX, it's one of the reasons I got rid of my STI...

 

I good a cheap monitor is Torque Pro if you use an Android phone or tablet. This way you can attach a number to your gauge.