Do I need an oil cooler?

[zeroomega]

Originally Posted by ZDan

IMO 275F is fine with 5w30...

Indeed mine almost always gets up to 270F indicated at the track, even on cooler days. But temps remain in control (i.e. no "runaway" oil temp rise) even on the hottest days.



IMO, it's not "insurance". Early ('13 model year) gen 1 cars seem to be overrepresented as far as bearing failures both without *and with* oil coolers. I think the earlier cars in particular had oil delivery issues. Oil cooler won't fix that. Also there have been failures with oil coolers due to leaky plumbing (well, at least 1 I can think of anyway).

I am not anticipating to start a conversation with you again on this topic. We cannot persuade each other. You took the risk to run your car on track without oil cooler and pushing your car beyond optimal temperature and oil pressure, that is your car, I don't want to say anything about it. For new comer who may want to drive the car in a more conservative envelop, please don't just boldly claim these conditions are OK. It didn't fail on your car doesn't mean they are good for all.

[jvincent]

Originally Posted by alex87f

Quick question on said coolers: while they protect the engine in a heavy-duty use case, how about their impact on daily driving? Any risk of running too cold, or seeing much increased warm-up times?

Do the aftermarket coolers have thermostats? And if yes how well do they work?

I'm not interested in putting one on my car, but this is where my question for useless-to-me information led me.

The OEM cooler actually warms the oil faster when cold (good thing) and then helps to keep it closer to the engine coolant temperature once it's warm so it's the best of both worlds.

Track performance is still TBD.

[RToyo86]

For 12 minutes sessions you can probably manage without.
Running a 5w30 may be a simpler solution than a full blown oil cooler if it's mostly a street driven car.

There haven't been any oil pressure testing done on the FA24 but FA20 testing showed 5w30 hold oil pressure better as temps went up compared to 0w20.

[timurrrr]

Oh, yet another thread on oil coolers for gen.1 with ZDan saying they are not needed

Coming back to the original topic of oil coolers for gen.2, most/all aftermarket options are not available / not on sale yet.
There's really not that much to discuss now.

If you want to go to the track now, the OEM cooler will be enough with 5w-30 or even perhaps good 0w-20 oil, assuming you check the oil temperatures every lap and start cooling down whenever you approach a certain "safe" temperature. It will get harder and harder to keep the car cool as summer approaches and ambient temperatures rise, but there's really not much else we can do.

Once aftermarket oil coolers from a couple of reputable brands are readily available to order then it will be interesting to see how they perform.

Originally Posted by ozafar

Wait what???? It comes with an oil cooler?!

Almost every article about gen.2 cars specifically said this was one of the biggest updates...

[Arthur-A]

With the type of oil cooler 2gen has, it would be better to not have it at all. It only makes installing proper oil cooler harder.

[ZDan]

Originally Posted by zeroomega

For new comer who may want to drive the car in a more conservative envelop, please don't just boldly claim these conditions are OK. It didn't fail on your car doesn't mean they are good for all.

I'm questioning whether it is *really* "more conservative". Bearing failures are skewed to affecting primarily '13 model-year cars, and seem to happen regardless of whether there's an oil cooler or not. But the assumption is always that oil is too hot, I've heard people frantically trying to figure out how to go even cooler than 220F after spun bearing *with* an oil cooler. IMO, it's not the oil temp that's the problem in 90% of these failures, it's the oil delivery...

It seems to me that insisting that a noob "just get an oil cooler" may cause more potential issues than it solves. While costing time/$$$/effort.

I do still think that 275F is not a prob with good 30 (or 40) weight synthetic in these cars...

[CSG Mike]

In the winter, oil temps are borderline.

For summer, oil cooler will 100% be needed.

This is for track use. Street guys will be fine without.

Spirited driving similar to track use.

[ozafar]

CSG Mike,

What do you use in your car for oil cooling?

[Robertw]

Originally Posted by ZDan

I'm questioning whether it is *really* "more conservative". Bearing failures are skewed to affecting primarily '13 model-year cars, and seem to happen regardless of whether there's an oil cooler or not. But the assumption is always that oil is too hot, I've heard people frantically trying to figure out how to go even cooler than 220F after spun bearing *with* an oil cooler. IMO, it's not the oil temp that's the problem in 90% of these failures, it's the oil delivery...

It seems to me that insisting that a noob "just get an oil cooler" may cause more potential issues than it solves. While costing time/$$$/effort.

I do still think that 275F is not a prob with good 30 (or 40) weight synthetic in these cars...

FWIW I have an alarm set to 260 F for oil temp in my turbo miata drift car, 5w-40. I change the oil every couple events. Personally, I wouldn't be comfortable running higher oil temps. 30 row setrab cooler, filter adapter plate with a t stat, no leaks or issues going on 5-6 years now. Oil gets up to operating temp as it did before the oil cooler.

I know the spec miata boys play with 270 F oil temps, but they're limited to what they can do cooling mods wise. They also rebuild motors every few seasons lol. If and when my GR order comes in, track days are on the agenda, and I'm picking up the largest aluminum radiator /oil cooler I can find. IMO, lower temps are always better.

I get things hot.




Does the FA24 have oil squirters?

[KillerBMotorsport]

We recommend knowing your on-track oil temps before stepping into an oil cooler. It's going to vary by driving technique, track, event type, and region. Adding unnecessary cost, weight, and complexity, (a potential DNF) is not a desirable direction for a track car, unless it's required.

Subaru engines in general have poor rod bearing supply because of the shared passages from main-to-rod bearings. There's no way around this achillies, unless you go to a billet crank with additional oil passages added. Making sure your oil type, brand, and weight, are good for your particular driving style, use, track, environmental conditions, etc. can be done with an Oil Analysis. That's not a guarantee of 100% reliability, but it's a step in a positive direction.

In regard to oil coolers, it's a tricky balance. The OEM cooler (or as the rest of the world calls it an 'oil heater') reduces the time it takes to get the oil up to temperature at startup. It also cools the oil, but because of the small temperature delta, it's not nearly as efficient as an oil cooler. As a cooler, it tempers temp peaks. It's absolutely does not cool anywhere as efficiently as a remote oil cooler.

When it comes to remote oil coolers there are a few things to consider. One, is that thermostatic valves don't close all the way. It will cool even when you don't want it to. This is by design to not thermally shock the engine when the valve does open fully. Some overcome this with a ball valve or even putting cardboard over the exchanger in cold temps. Size the cooler no bigger than what you need, because cold oil is far more damaging than hot oil. If you're in a colder climate, keep the OEM cooler in place when you add a remote cooler. If you're in a hot climate, remove the OEM oil cooler; this will more efficiently cool the oil, and remove a heat load from the cooling system.

The above are generalizations. If you have more specific info conditions, the conversation continues. It also assumed casual-to-regular track use. Not once or twice a year, not on a competition level.

[KillerBMotorsport]

Originally Posted by Robertw

Does the FA24 have oil squirters?

No, but it has notched rods.

[ozafar]

So wouldn’t the problem be solved by getting a really good thick radiator and some 1500 cfm spal fans? That would help remove the heat the water is taking on from the oem oil “cooler”

[ZDan]

As little as I think this car "needs" an oil cooler for limited track usage, I 10x as much think it doesn't need a huge aftermarket aluminum radiator.

My gen 1 only gets barely over 200F coolant temps at the track. Doubtful the new one is lacking in cooling here. If you want cooler oil, getting a huge Al radiator and fans just to get slightly less warm coolant temps in that tiny water-oil heat exchanger isn't IMO gonna be the way to go...

[wbradley]

The oil to water heat exchanger appears to be the same unit that is on the FA24T. The engine oil should warm up quicker on cold days, which is good for the turbo.

Keep in mind gen 2 has the same size engine bay with no additional external cooling or vents and with a 20% larger displacement engine so if heat buildup on the FA20 models was borderline, Subaru likely assessed that they will require the addition of the cooler on the bigger engine. Since they already put the cooler on the turbo engines which likely are assembled together with the na version it doesn't force them to vary production too much, keeping the cost reasonable.