What's the verdict on the need of oil cooler?

[rice_classic]

Oh wow.. I didn't realize how big that wall of text was until I hit submit. Sorry guys.

[orthojoe]

Originally Posted by rice_classic

Here's my thoughts on oil, pressure and temp. I do not claim these as truths or facts but observations, opinions and recommendations.

The OEM engine is designed to run 100C oil during normal city driving, sometimes a bit more or less depending on conditions. So don't worry about 100C temps, or even 130C (only 266F). Synthetic oil won't break down but if you're going to sustain temps above 120C then you can take two routes:

1: Cool your oil
or
2: Thicken your oil

Neither is wrong or right inherently, the point is to hit the target. The whole point of the game is to match cSt to temp and pressure to RPM. Our engine is designed to be at roughly 8-9cSt @100C and we should have 10 PSI of pressure for every 1000RPMs.

What happens if I install an oil cooler and I'm at 110-120C but I don't have enough pressure? Well, then I need to consider something thicker than the 0w-20. And guess what, our factory manual even states that a thicker oil may be needed for track use.

Basically the reality is that engines like heat, actually they LOVE IT. After all, the hotter they are, the more efficient they become but the problem with that is that at some point things melt, things expand, things go...kaboom. So while engines love heat from an thermodynamic efficiency point of view, their parts do not. So we have to keep our heat in check. The answer isn't always cooler = better. There's nothing wrong with running high oil temps, really high oil temps... ask the Audi Lemans teams or Joe Gibbs or Ferrari. The oil, however, has to be able to withstand it and Joe Gibbs, AUDI Le Mans and Ferrari F1 aren't buying off the shelf oil.

"But rice, if we can run really hot oil and engines like heat, why would anyone install an oil cooler?"

OK, so we know that a good synthetic oil can withstand 300F or 150C for extended durations and we know that amount of temp isn't over burdening the metal of the engine so why seek to lower it? The answer? So we can add more power!!!... or at the very least keep from losing what we have.

Oil is also a coolant for our engines and as this vital cooling fluid becomes hotter it doesn't pull as much heat away from really hot areas. The result is that oil's decreased ability to do its job as a coolant can lead to our engine developing knock and forcing the computer to retard timing... LOST POWER. On the flip side, if we cool our oil very effectively then we might be able to add power like advancing timing or increasing boost without developing ping/knock/pre-det.

So on a track dedicated car or a race car the oil cooler makes really good sense from a maximizing-every-advantage aspect. On a daily driver with an oil you cooler you face the fact that your oil can take much longer to heat up and you could be running your engine less efficiently by over cooling your oil (which thickens it). So yeah, it will do a great job while on track but for 99% of the miles you're going to put on it, it may be overkill.. or it may not. Look at your readings after install, only those will be definitive. Another option is an oil cooler with a thermostat to give you optimal temps all the time.

p.s. I run an oil cooler on my race car, my direct competitor (same car) does not. I use a 30w or a 40w and he uses a 40w or 50w. His engines last just as long as mine (sometimes longer but that's another topic!).

Great post. Thanks for taking the time to write it up! Much appreciated.

[OrbitalEllipses]

Originally Posted by rice_classic

Oh wow.. I didn't realize how big that wall of text was until I hit submit. Sorry guys.

No need. Thanks. :happy0180:

[CSG Mike]

Originally Posted by orthojoe

Totally OT, but since I have your attention, how many miles do you think I should have on the car before my track day in March? I figured 1000 miles would be ok, but why not get an opinion?

We tracked with less than that on the ODO

[ultra]

Any consensus yet then?

As fas as I can tell so far an oil cooler isn't an absolute neccessity as long as you're running a thicker oil on the track.

I'm curious about how too-think oil vs. too cool oil compare when not at the track, i.e. which would be preferrable?

Half tempted to have a go on the stock oil but I live in the desert, we do 3x20 minute stints and I'm a pretty experienced driver (no holding back except for safety) so I'm a little unconvinced so far. No doubt the car would last a few times on the stock oil but I wouldn't want to start damaging stuff that'll rear its ugly head later on.

Thanks for the posts so far though!

[CSG Mike]

In Dubai? I'd get one...

[Dave-ROR]

I'm ordering the last bits I'll need today.. basically a few aeroquip fittings, SS line tool (cutting ss line is a PITA and even worse without it), the mocal sandwich adapter and some aluminum blocks to use as standoffs and wider mounting bases for the cooler. I might deal with the install next weekend, going to sebring this weekend.

[orthojoe]

Good news. I just heard back from my source at AiM, and they are coming up with an updated ECU protocol for our cars that logs 16 channels. Hopefully one of them is oil temp. I'll let you guys know when I test it out in the next week or so.

[Huehuecoyotl]

Ecutek looks like it will log anything obd2 so it will log oil temps. This picture is from Perrin blog. About to go this way I think

[celica73]

You can view and log oil temp using the Toyota Techstream software (and any other ECU parameter). $20-30 for the cable (eBay) and a free software download (most also come with some version of the software). I plan to try it out one of these days. You can also mess with a bunch of other things (like turn off the headlight timer - you know for when you install a 2 lb LiFePo battery).

[zoomzoomers]

Great stuff guys!

[Dave-ROR]

Parts have been ordered

Assuming it fits, my setup will consist of:
Mocal 19 row 235 cooler (already have this)
Aeroquip SS hose (-10AN) (already have this)
Mocal sandwich plate with spacer
Cheap sandwich plate for oil temp and oil pressure gauges (already have this)
Defi Advance CR gauges, going to have to find a place to mount the control box (already have this)
Assorted Aeroquip -10AN reusable fittings (already have some of these)
Blood from cutting SS hoses (already have, just not relocated to the hoses yet...)
Zip ties
Maybe some AL blocks to make the mounting more stable, going to check spacing first.

[celica73]

Wrap the braided line in masking tape and cut the braiding using any rotary cutting tool (air, dremel). Once that is done, finish the job with a sharp blade.

Not going all the way through the the rotary tool keeps debris out of the hose.

[Dave-ROR]

Originally Posted by celica73

Wrap the braided line in masking tape and cut the braiding using any rotary cutting tool (air, dremel). Once that is done, finish the job with a sharp blade.

Not going all the way through the the rotary tool keeps debris out of the hose.

That's what I do, well minus stopping, I just clean out the hoses with oil and air first. So good idea on stopping.. I'm actually hoping that my existing hoses will be the right length so I can just swap some 90 deg fittings to straight fittings.

I know I won't be that lucky though