Oil Cooler/Reliability Mods

[CSG Mike]

Surely, there must be a reason someone decided that lower oil temps were better on the FA24, even though it results in worse fuel economy.

[CSG Mike]

Originally Posted by Autoxer62

FWIW, after reading a lot of threads, I have settled on the following oil system mods for our intended STX build next year:

- Killer B oil pickup
- Moroso oil pan baffle
- Forester oil cooler
- Mobil 1 5w30

--Bryan

Don't bother with the pickup and baffle. You won't need them.

[Dzmitry]

Originally Posted by Icecreamtruk

You are 100% right, engines fail under all sort of circumstances and I have 0 ways of proving you are wrong at all. But based on what I've seen on track used cars, I'll stick to my approach. Like they say, YMMV. I also think there are a bunch of people who dont understand that because your oil can and will survive being held at 272F for a whole track day, that does not mean you can also do 5k miles oil intervale changes (while doing track work in between as well). Oil does degrade faster the hotter it gets (and not only engine oil, but transmissions and diff oil as well, which is never mentioned here apparently).

Very true, hence why I believe in good oil maintenance intervals, all depending on how you utilize the car. Even as a DD, with oil temps reaching as high as 230 on work drives, I tend to change mine every 3k miles, especially when I'm using 0W-20 in the winter. I never understood why people skimp out on that... Buy your own oil, the oil change costs no more than a full gas tank if you take it to a shop. My dad was a perfect example of that when he always stretched his old Outback intervals to 6-7k on non-synthetic oil. Engine said bye eventually.

[Ultramaroon]

Originally Posted by DarkSunrise

Does anyone know what oil cooler kit they were using for that testing? Size/shape of the oil cooler, fittings, and bends can play a role in how much pressure loss there is from the oil cooler, not to mention the effectiveness of the cooler itself in dropping oil temps.

A poorly designed undersized oil cooler might actually make things worse by causing a large pressure drop and not reducing oil temps significantly. Worst of both worlds.

Conversely a well designed, properly sized oil cooler that keeps temps in the 220’s and doesn’t create a large pressure drop would be undeniably beneficial for oil pressure on the track, especially paired with a 30 weight oil.

As with all things it’s likely to come down to the details.

Indeed

[DarkSunrise]

Originally Posted by Ultramaroon

Indeed

That's amazing I always wondered why nobody had tried rotating a tall/narrow oil cooler like that to reduce the flow restriction. Great to see it actually done!

[Ultramaroon]

BTW, that scatter plot is for shit, really. Addition of the oil cooler data does nothing but show head loss from its use. A cooler doesn't change the thermal properties of the oil itself.

Originally Posted by DarkSunrise

That's amazing I always wondered why nobody had tried rotating a tall/narrow oil cooler like that to reduce the flow restriction. Great to see it actually done!

It absolutely works as intended. Thanks!

[racingfool]

never thought i'd see aero and wind tunnels used for testing coolers

[jflogerzi]

Originally Posted by Dzmitry

Slightly off topic, but with gen2 release, nice to see they threw in their basic oil cooler into the car. Might be the perfect fix to more extreme temperatures. We'll have to see how it plays out.

It's just the oem cooler found on the wrx... It's not a true cooler. More for warm-up in colder climate vs cooling

Sent from my GM1915 using Tapatalk

[rice_classic]

They should touch... the oil cooler and radiator, they should touch (ideally) unless a low pressure can be created behind.

I don’t remember where I saw the research but when an oil cooler is placed in front of a radiator with a gap in between the air turbulence between the two reduces the flow behind the oil cooler and through the radiator. However if the fans are running behind the radiator then a low enough pressure zone is created that mitigates it.

If the two are touching then the air flows through both without impedance - no fans needed.



Kind of moot point here since just about everyone has fans running but still interesting. On my former car I had a fan on only half the radiator so I made sure to mount the oil cooler on that side.

[Dzmitry]

Originally Posted by Ultramaroon

BTW, that scatter plot is for shit, really. Addition of the oil cooler data does nothing but show head loss from its use. A cooler doesn't change the thermal properties of the oil itself.


It absolutely works as intended. Thanks!

Right, but I don't think anyone here was claiming that the oil cooler changed the thermal properties of the oil. The plot is simply used to show pressure changes at various temperatures.

[Dzmitry]

Originally Posted by jflogerzi

It's just the oem cooler found on the wrx... It's not a true cooler. More for warm-up in colder climate vs cooling

Sent from my GM1915 using Tapatalk

Seems to work fairly well to assist in cooling from what I've read. One of the guys out there reported some data at peaking no more than 260F at his most extreme conditions, when he would usually peak around 275F-280F without the cooler. We can certainly say that for DD, this would probably be great at keeping temps optimal temps at all times, and for light track use or autocross it should do just fine. This would cover the MAJORITY of the car owners. Only the few out there going extra hard may even need to consider getting something aftermarket. Those going hard know what they are getting into anyway, and are likely throwing money on all kinds of aftermarket parts for competition.

Also, from doing some quick reading (as I don't know a lot about the WRX yet), WRX owners don't seem to get up past 260 much either with track use.

[ZDan]

Originally Posted by Ultramaroon

BTW, that scatter plot is for shit, really. Addition of the oil cooler data does nothing but show head loss from its use. A cooler doesn't change the thermal properties of the oil itself.

Pressure loss due to cooler is worth knowing, along with how much it cools the oil. That was the point of showing it.

[M0nk3y]

Originally Posted by CSG Mike

Don't bother with the pickup and baffle. You won't need them.

Both of those parts would also be illegal for STX class, FWIW

[M0nk3y]

Originally Posted by ZDan

No idea unfortunately. Brings up a very good point though: what are most people gonna pick out if they "have to get an oil cooler"? The cheapest/crappiest one out there...

Luckily for the most part most aftermarket companies have standardized around the Setrab coolers, specifically around the 613 series.

19k-26k btu/hr IIRC off the top of my head and 3 psi of pressure drop. Which is pretty insignificant if you look at the benefit it provides.