Quote:
Originally Posted by ZDan
I might consider an oil cooler IF I were endurance racing, or IF oil temp continued to climb (always holds at just over 270F indicated, whatever the ambient temp), or IF coolant temps were a problem (always runs middle of the gauge even at 95F track days).
Anyway, that's my reasoning and I'm open to critique of it.
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Toyota Motorsport Germany disagrees. But hey, what do actual Toyota mechanical engineers who build and re-build countless of these race cars/motors know about the effects of oil temp, pressure, and low oil weight/viscosities. They started with 10W60 but then just recently moved to 5W50. They also know the inherent oil pressure issues with the block design, and how one port has to cover two journals, and there is no bearing priority oiling in this system. So the only reasonable way to help offset those glaring issues, is by controlling temps and viscosities/weights, which go hand in hand.
If you think for one second you are "harming" your engine more by running 5w40 or 5w50 for tracking days and leaving it in, instead of using 0W20 or 5W30, then I'm not sure you will ever understand. The wear that happens on a track in those "short" 20 minute sessions under high load are WAY more than thousands of commuter miles, or "hard" street miles.
I also trust data. Here is my actual real life on-track data. 66F day, at Gingerman. Full race car on hoosiers, turning 1:41 laps, which means the car is getting wailed on harder than any street car is. I chose to run 5W40 because of the cooler temps and we are sprint racing, in summer heat I will use 5W50. Jackson racing cooler, upgraded radiator, and side ducting to keep the air flowing through the radiator and not outside the frame rails. If you want perfect, this is about as perfect as it gets. 206-217 oil temps, 194-197 water temp, and oil pressure is decent, although I'm probably going to switch to 5W50 simply for the oil pressure increase, and keep the bearings better lubricated. Everything just gets hotter in 80-95F ambient temps......which means that 5W50 is honestly what you prob want to be running all summer long for track days and daily driving.
My specs are what knowledgeable engine builders here, and TMG recommend for ANY FRS/BRZ that is being run on track. That data supports it. See the big pressure drops, even with my oil pan baffle, and 5W40? That's clear as day. No way I want to be running at 240-250F, much less 270F with a 5W30. LOL.
So basically, I don't care who you are, you must be nuts to be tracking with anything less than 0W40 or 5W40, daily driver or not.
So that's my reasoning, which seems a little more sound than "my owners manual says 5W30", or "I read it in a forum".