Oil Cooling - An In-Depth Look

[Decay107]

Originally Posted by brzaapi

Eric (and many others) know more about this than i do. But to be honest, dont buy an oil cooler till you need one. Next time you hit your AX/HPDE, monitor your oil temps to see if you are very high. As you progress or get faster you may require one. But, dont add one till you need one. If your HPDE keeps getting cut short due to heat soak and high oil temps, then you need an oil cooler. But I dont see the reason to buy one just cause you hit the track a couple of time. Its just another place to check for leaks anyway.

Plus the car wont really let you hurt it. It will start retarding things if the temps go too north of 300*F.

Except the oil pressure north of 240 is well out of manufacturer specification, that should realistically be the point you look at oil coolers. A novice can easily get there within a few laps on a stock fa20.

[steve99]

Originally Posted by brzaapi

Eric (and many others) know more about this than i do. But to be honest, dont buy an oil cooler till you need one. Next time you hit your AX/HPDE, monitor your oil temps to see if you are very high. As you progress or get faster you may require one. But, dont add one till you need one. If your HPDE keeps getting cut short due to heat soak and high oil temps, then you need an oil cooler. But I dont see the reason to buy one just cause you hit the track a couple of time. Its just another place to check for leaks anyway.

Plus the car wont really let you hurt it. It will start retarding things if the temps go too north of 300*F.

Im not confident that the ECU will save the engine if oil temps get to high.

Ecutek and Romraider guys have discovered tables in ECU that apply a timing reduction on intake air temperature IAT this is active in stock roms and could be adjusted by tuner.

there is also a table for ignition timing retard vs Coolant temperature , however this table is not used in stock rom/tune, but can be used by a tuner.

These are likely intended to reduce knock, rarther than save engine.

Their does not appear to be a "discovered" table that retards timing or reduces throttle input etc for oil temp. This does not mean it does not exist though.

I saw perrins blog where they hinted that high oil temps caused a loss of power but they did not appear to be monitoring coolant or intake air temps so ill take it with a grain of salt.

If you read this info by ecutek, see the section on custom maps. Ecutek are suggesting you can create a custom map using oil temp as an input and apply a torque reduction or timing reduction or completly knobble the throttle to say 30% max as oil temp increases.

http://www.ecutek.com.au/ecu-product...t86-scion-fr-s

This seems to suggest that their might be no facilty in the standard rom software that "saves" the engine in time for ecesssive oil temps.

Its certianly possible that the ecu could trip into "limp home mode" on severly excessive oil or coolant temps. But the damage may already have been done especially on modified engines or during track use.

Thier is also no oil pressure info sent to ecu on these cars, the idiot light for oil completly bypasses ecu from memory and just lights the dash light. Its just a switch and as long as oil pressure is above about 2 or 3 psi it stay off. It should be relabeled "replace engine" :-)

Stock their is no oil pressure sender only a oil temperature sender.

Ecutek guys also did some work on using an external oil pressure sender to feed info into the ecu and use a custom map to use oil pressure vs rpm to create a safety trip map if you get low oil pressure at eny rpm, ie less than whats in the custom map.

http://www.ft86club.com/forums/showthread.php?t=95989

This is where the problem is, hot oil looses viscosity even the race type oils (they loose less viscosity though), as temps rise pressure drops and at high rpm and loads damage can result from to low a pressure rather than the oil physically breaking down.

[brzaapi]

Like I said, you all know more about these cars than i do for sure. I get all my cars tuned, but i am not a code monkey, though i love reading all the information i find here. Steve99 you definitely have words of wisdom.

But, my posts intent was just to make all the information simple to the average driver. In other words dont over think it. You will know when an oil cooler is needed. I am about to pick up my 4th BRZ (no the other 3 didnt die because i refused to buy an oil cooler, quite the contrary) and the first thing going on it will likely be my JR radiator/oil cooler combo. In fact its sitting in a box on the floor waiting for my 17 BRZ to be delivered. I know i need an oil cooler.

I dont know what tables are in the ECU, and I can not claim to know anything about the process. But, what i do know with multiple BRZs i have tracked....is that the car will let you know the minute its not happy. Once i see oil temps around 315F give or take the car cuts revs. You will know it when it happens. And that means take a cool down lap or two and its time to go park. There are many factors with this, that track guys will likely have learned. As far as oil weight, and interval to change and so forth. Luckily this car is the easiest oil change in the world. My wife thinks it is still work, when i go out do it. But she doesnt know that changing oil on this car is something i find fun and relaxing. It gives me about an hour to myself in the garage.

But for a new-ish guy i was just trying to say dont think you can't go turn some laps without an oil cooler. That, the car will let you know if you need an oil cooler. That being said, because the BRZ runs such lite oil, and the oil temps can get high fast in stock form. Having some way to monitor oil is a great idea in this car if you plan on hitting anything longer than an AX.

So, again I am no expert. But, new guys dont get overwhelmed with the knowledge shared. Just take it in and keep it in mind. You will know when its time for an oil cooler, it literally is the first thing i would buy for my twin. But, if you are not on the track I dont think you would need one.

[Decay107]

Originally Posted by brzaapi

Like I said, you all know more about these cars than i do for sure. I get all my cars tuned, but i am not a code monkey, though i love reading all the information i find here. Steve99 you definitely have words of wisdom.

But, my posts intent was just to make all the information simple to the average driver. In other words dont over think it. You will know when an oil cooler is needed. I am about to pick up my 4th BRZ (no the other 3 didnt die because i refused to buy an oil cooler, quite the contrary) and the first thing going on it will likely be my JR radiator/oil cooler combo. In fact its sitting in a box on the floor waiting for my 17 BRZ to be delivered. I know i need an oil cooler.

I dont know what tables are in the ECU, and I can not claim to know anything about the process. But, what i do know with multiple BRZs i have tracked....is that the car will let you know the minute its not happy. Once i see oil temps around 315F give or take the car cuts revs. You will know it when it happens. And that means take a cool down lap or two and its time to go park. There are many factors with this, that track guys will likely have learned. As far as oil weight, and interval to change and so forth. Luckily this car is the easiest oil change in the world. My wife thinks it is still work, when i go out do it. But she doesnt know that changing oil on this car is something i find fun and relaxing. It gives me about an hour to myself in the garage.

But for a new-ish guy i was just trying to say dont think you can't go turn some laps without an oil cooler. That, the car will let you know if you need an oil cooler. That being said, because the BRZ runs such lite oil, and the oil temps can get high fast in stock form. Having some way to monitor oil is a great idea in this car if you plan on hitting anything longer than an AX.

So, again I am no expert. But, new guys dont get overwhelmed with the knowledge shared. Just take it in and keep it in mind. You will know when its time for an oil cooler, it literally is the first thing i would buy for my twin. But, if you are not on the track I dont think you would need one.

Dear god, please install an oil pressure gauge... for science! I want to know what pressure looks like near redline at 315

I get scared of the pressure deficiency (about 20 below MFR specification) at 245F on thick leaning 5w-30 oil.

[brzaapi]

Originally Posted by Decay107

Dear god, please install an oil pressure gauge... for science! I want to know what pressure looks like near redline at 315

I get scared of the pressure deficiency (about 20 below MFR specification) at 245F on thick leaning 5w-30 oil.

That actually would be good. I know i never saw it higher than 100psi, but to be honest i dont remember to well sincethis was a grind session at Eagles Canyon to see what the BRZ could do on the track....prior to any real mods.

Now i did have all motul fluids in the car, and i was running 5w-30. That being said, once temps got above 265F boy did 300F come damn fast. And I tried to go back out on the track an hour later, and found that i couldnt complete more than 2 laps in that session. So I called it a day.

Wish my memory of the day was better, but when i managed to look at psi i dont remember any less than 30 or more than right at a 100psi. But it was 4 years ago.

Anyway, I dont even touch a track without addressing oil now in any car of mine. But for you new track guys, please dont let that scare you from beginning your track journey. You will know when its time for more cooling, at that is all my butt was trying to say. Try tracking the car then, see if you need to add mods for cooling or braking or whatever.

Again, i just dont want anyone to not track becuase they dont have this or that. Track first, unless your damn gifted...oil temps should not be a big concern.

[JazzleSAURUS]

Great read, thanks Eric.

I'm planning on the Forester OEM cooler for mine since I do a lot of long windy roads, (think the kank cruise, driven hard,) a few local mountain passes that are fairly extensive, autox, occasional track day.

As peace of mind, it's a nice part. I see my oil pressure dipping a bit towards the end of these longer runs, which I'd like to negate.

[Overdrive]

Is it a plug and play part?

[weederr33]

Originally Posted by JazzleSAURUS

Great read, thanks Eric.

I'm planning on the Forester OEM cooler for mine since I do a lot of long windy roads, (think the kank cruise, driven hard,) a few local mountain passes that are fairly extensive, autox, occasional track day.

As peace of mind, it's a nice part. I see my oil pressure dipping a bit towards the end of these longer runs, which I'd like to negate.

I have all the ingredients for the oem kit, but I failed myself by nearly stripping the block off bolt you use under the engine. And the throttle body route is out of the question.

[MurderousPandas]

I have a well modified FRS, but i plan to keep it NA for a while. Would an O2W cooler be beneficial in a NA setup? These cars heat up a lot, even stock, so i want to get one, but i'm worried about overcooling or incorrect cooling setup. I don't have numbers right now, but i do notice performance drop after driving the car for sometime.

"Chasing speed with patience"

[Tor]

Originally Posted by VeloxEric

Engine oil, on the other hand, is expected to reach much higher temperatures! Anyone telling you otherwise should be questioned intently. Engine oil needs to reach *at least* 100 degrees C (212 degrees F) to burn off condensation (water) build up within the engine *which is perfectly normal and happens in every single engine*. If oil does not reach this temperature, the oil is unable to do its job to the best of its abilities and increased engine wear will result.

I propose that this is an utter myth! Obviously, water evaporates at temperatures at all temperatures, not just when boiling (that's why e.g. streets dry up after it has been raining).

Next, living in the country (Germany) with probably the highest failure rate of FA20 engines I would strongly advise against running oil temperatures above 100-110 deg C (212-230 f) on a daily basis. The reason for that is simply that the oil degrades much faster due to thermal breakdown - at a rate twice as fast for every added 10 deg C (18 f).

Almost every single reported engine failure (non-modified NA engines) that we have here occurred because people drive their cars regularly above 200 km/h (125 mph) on speed unrestricted Autobahn while sticking to the factory specified oil change intervals of 15.000 km (9320 miles).

Funny enough, for comparison, not a single car that is being tracked here ever blew an engine - pretty much everyone that tracks their car regularly has an oil cooler installed.

Personally, I run a 9-row oil to air cooler with the prescribed 0W20 oil. I am perfectly happy with oil temperatures of 80-90 deg C (176-194 f) on the street and 105-115 C (221-239 f) on track, and I still change the oil twice as often as prescribed by Subaru.

Non-aggressive daily driving the engine stock, without an oil cooler, it runs between 90-95 deg (194-203 f).

From the empirical evidence that we have with the correlation between subjecting the engine (or rather the oil) to high temperature, sticking to prescribed oil change intervals and engine failure rates, I can only say that this part of your write-up is extremely bad advice and may lull people into the belief that "it is okay" to daily see oil temperatures way above 212 f, when in actual it's the perfect recipe for an engine failure.

[solidONE]

Originally Posted by MurderousPandas

I have a well modified FRS, but i plan to keep it NA for a while. Would an O2W cooler be beneficial in a NA setup? These cars heat up a lot, even stock, so i want to get one, but i'm worried about overcooling or incorrect cooling setup. I don't have numbers right now, but i do notice performance drop after driving the car for sometime.

"Chasing speed with patience"

I don't think you'll ever run into 'overcooling' problems with a O2W cooler. From what I've seen and having spoke with a couple of guys using them, oil temps will still get hotter than 240-250 during a 20 minute session on track. Still better than with no oil cooler at all.

With an A2O unit, even with a thermostatic switch, people have a hard time getting up to operating temps under normal use. It will keep the temps floating around or under 240 on a NA car during 20 minute session on track though.

[Traktor]

What about stacking a forester O2W with a O2A? Then you mitigate against over cooling on the street, but have better cooling on track.
I've never seen anyone do this.


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[steve99]

Originally Posted by Traktor

What about stacking a forester O2W with a O2A? Then you mitigate against over cooling on the street, but have better cooling on track.
I've never seen anyone do this.


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mishimoto guys did it on wrx, appears to be enough clearance to do same on brz/86

http://engineering.mishimoto.com/cat...oler-kit-2015/

[Calvin27]

Looking at oil cooling options atm. There seems to be a lot of oil cooler threads on here so I figure I won't start a new thread lol.

Anyways, for those that run an oil cooler, how to do you do an oil change? Do you just accept that the change will retain about 600ml of the old stuff or is there actually a way to drain it? I'm surprised this isn't built into most oil coolers.

Second, without a thermostat, you could potentially do the easy solution of a drop in barrier to block the radiator and/or simply warm the car up before driving. Also what about a simple manual operated valve - this works because you know when you are gonig to be tracking or spirited driving for a prolonged period before you drive.

Third, what exactly is the mechanism in the thermostats for air based cooling?

All of this research is making me dizzy and if it weren't for the prospects of oil spills from a proven system, I'd have a jolly crack at DIYing my own solution.