What would improve overall/global cooling more: Oil Cooler or Performance Radiator?
 

Let's say, you aren't the richest person in the world, and you would like to get your 1st high performance cooling modification part, and can get only 1 part.

Which would you buy first and which would help the most in global/overall engine cooling (both oil and coolant/water temperatures)...?

...an oil cooler, or a new aftermarket plug-n-play/drop-in radiator (ie: Koyo, Mishimoto, etc.)?


From what I've read(correct me if I'm wrong), the water/coolant temperatures don't really get super hot at the track. On the other hand/end however, some people said that the oil temperatures get hot sometimes during hard laps.

Obviously, an aftermarket radiator addresses the water temps first(which aren't the first concern, as the oil is more of a priority I believe), and would secondarily help the oil temps by bringing the overall engine temps down with the new radiator and cooler water temps.

So, since we need to address the oil temps first, would getting an oil cooler first be the better/smarter choice? ...since an oil cooler would address both the oil temps firstly, and then secondarily and also additionally bring overall engine temps down and the water temps down as well, from the cooler oil?

Oil cooler.

https://dl.dropboxusercontent.com/u/...5-16-36-34.png

These were my temps during that last track event in Chuckwalla.

CARNZ did a DIY to install a Forester XT oil cooler (coolant-to-oil, not air-to-oil) here. I asked him about the idea of using the coolant lines from the throttle body (seen here) instead of running them from the block, and he didn't see a problem with it. I know some turbo kits use those lines, so there may be conflict if you have a turbo.

why not both? I ordered both Koyo Radiator and OEM Oil cooler. I figured the OEM unit utilizes the radiator so by upgrading the radiator capacity you also improve the effectiveness of the oil cooler. This is the case with many sports cars that come with oil cooler from factory (not exactly sure why Subaru didn't include the oil cooler anyways) including Miatas, Corvettes..etc

why does everyone think the FT86 needs a bigger radiator? I drive mine on track in 108f temps with the AC on sitting in the hot pits....then turn it off on track with windows down...car never-ever waivered....always right in its normal temp spot.

Oil cooler is a good idea, especially with such light weight oils....

FWIW, last weekend at Chuckwalla:

Peak coolant temp w/ heater to "Hi" but blower on lowest setting was at most ~95C
Peak oil temp w/ Cusco oil cooler (same as Forester kit, sandwich adapter) was 116C

Without this, oil temps of 130-140C would have been reached easily (documented on multiple occasions by other people)

-alex

Yeah I think oil cooler is needed even on a stock car in hot temps during track days, really don't know why they didn't include the OEM one from the FA20DIT... Radiator is a FI upgrade.

Most OEM gauges are not linear. They have steps and you won't know it's too hot until it's too late.

With that said, I'm going to be doing a coolant and oil temp gauge and then do some road course testing. Then we will put in an oil cooler and retest. Then a radiator and retest.

-Mike Paisan

http://www.pbase.com/paisan/image/153798190.jpg
Maintaining, Modifying and Educating TriState Enthusiasts since 2001.
Like us on Facebook! | E-mail: sales@azpinstalls.com | 725 Fairfield Ave | Kenilworth, NJ 07033 | 908.248.AZP1 (2971) |AIM: AZP Installs
"Race Tested, Enthusiast Approved!"

What app is that?

-Mike Paisan

http://www.pbase.com/paisan/image/153798190.jpg
Maintaining, Modifying and Educating TriState Enthusiasts since 2001.
Like us on Facebook! | E-mail: sales@azpinstalls.com | 725 Fairfield Ave | Kenilworth, NJ 07033 | 908.248.AZP1 (2971) |AIM: AZP Installs
"Race Tested, Enthusiast Approved!"

torque the defacto obd2 auto app for android.

thanks. :)

Wasn't sure if it was an actual gauge sensor or if it was just reading OBDII.

-mike

I seem to be one of the only ones on the forum that have seen higher coolant temps on the stock radiator. Coolant was always up to 212F in long idling, autox, dyno.

Even after I added the Koyo, same issue, it just would take longer to heat soak but quicker to cool in open air or when fans kicked on.

Sounds like a bad T-stat possibly?

-Mike Paisan

http://www.pbase.com/paisan/image/153798190.jpg
Maintaining, Modifying and Educating TriState Enthusiasts since 2001.
Like us on Facebook! | E-mail: sales@azpinstalls.com | 725 Fairfield Ave | Kenilworth, NJ 07033 | 908.248.AZP1 (2971) |AIM: AZP Installs
"Race Tested, Enthusiast Approved!"

I am working on getting a new oil cooler for my car (stock engine BRZ).

I don't think i've ever seen the coolant temp go over 100 C but on the track (I've watched it at Laguna Seca and Thunderhill) I hit oil temps of about 125 pretty easily (even on cooler days). Also doing pad bed in on the freeway late at night (ie. when no one is around in cool weather, I speed up to ~70 mph and brake hard to 20, rinse repeat a few times) I've seen oil temperatures hit 135.

From everything I've heard that kind of temperature will quickly degrade even the best of oils. Because of this I currently am theorizing that an oil cooler is very much needed and am planning on getting the jackson racing one (I've been told that they will release one with non-FI mounting in time for my next track day).

Air-to-oil vs water-to-oil coolers?

Is it me..or does it sound like water-to-oil (ie: cusco, oem forester, etc.) cooler are a little redundant and not as effective?

Meaning... aren't all cars with a radiator effectively like a giant "water-to-oil" cooler already? ...especially since all the coolant passes inside the head and block already and is already cooling the same thing - the oil and the block. Wouldn't re-routing the lines be effectively almost the exact same thing as just leaving it bone stock with no water-to-oil cooler? Idk...just the way I see it, Lol. Anyone else think this too, or am I the only one? I can't really see this(a water-to-oil cooler) being much different than stock or being much different without one.

Just sounds a bit gimmicky to me. And, if you think a forester having a similar water-to-oil cooler as oem means it's not a gimmick; then why didn't they put it on all subaru models? Maybe subaru saw that it didn't really work, so they didn't put it on their other models.

subaru actually have used a variation of the forester cooler (no cup because bottom mount, and a couple versions of fitting orientation) on all the turbo models iirc.

Granted historically the unit has been more referred to as an "oil warmer" over on places like nasioc the results shown in various posts here on this platform do show that it at least has some positive effect with regard to regulation, temperature drop time, and warmup time.

Wether these methods are as effective as an air to oil cooer is not up for debate, they aren't, in terms of pure oil cooling the air-oil coolers are superior. But cooling isnt the sole factor to be considered. For many especially those in colder climates oemish water-oil offers other aspects that are very appealing (winter advantages, less risk of leak, etc).

There are pros and cons to both, but for the average person, oil-air will be superior.

We DO have a lot of oil-water experience (S2ks come with one from the factory and we use a rather large unit when we boost), and are nice when you have packaging constraints due to limited space, but if you have the space, always use an oil-air cooler.

theoretically, water to oil coolers combined with a bigger radiator will help reducing the oil temps ..at least, this is the case with many cars that come with water to oil coolers from factory, you basically upgrade radiator not because your OEM radiator isn't sufficient to keep the coolant temps lows and steady but because it will help alleviate high oil temps...many Vette and Miata owners don't even bother changing the OEM oil cooler they simply upgrade their radiator and it does automatically..

We logged with my friend's Z06 before and after the bigger radiator (similar ambient temps).. and after adding a bigger radiator oil temps dropped to ~230 F from ~260F..

I realize there have been some issues with delivery, but my car has a Robi-Cooler and there are zero issues with oil or coolant temps getiing too hot in any condition. My only concern is that oil temps actually run 170's in the Florida winter which may be no issue at all.

At Sebring in the summer last year, oil temps hit 300*, and this past winter oil was consistently in the high 270*s.

To be quite honest, I have been against an air/liquid oil cooler for a while as I've seen plenty of cars catch fire due to an oil line leaking on track, and have done UOA's after each oil change, which includes several track days on each fill, and even when oil temps hit 300*, the UOA results were great. Even water temps were normal (~206-212*) while oil temps were sky high. Not only that, but from the race team engineers I have talked to, I have been told that high oil temps (270-300*) is more of a power issue than an engine reliability issue, due to the way engines, and more importantly oils, are made today. You also have more failure points in the oiling system and changing in oil pressures to deal with. That is one of the reason's why I like the idea of a liquid/liquid setup using the OEM Forester setup or Cusco kit, as I would much rather have a coolant line leak or fail than an oil line. However, for track use, I just don't think either of those are enough in severe climates like track events in the summer down south or out west.

With that said, I have been chasing lap times, and it is annoying how much power I will lose with high oil temps - a seriously noticeable power loss. I think you will gain more power on a track-use car by running an oil cooler vs. bolt ons like full exhaust and tune, and despite all of the negatives, I'm about ready to bite the bullet and go with an air/liquid cooler like the Jackson Racing or Perrin kit.

If only there was an easy way to import the BRZ RA edition oil cooler. OEM quality and fitment.

Not likely it would either never get hot or overheat right away. It does neither of those things.