Grandavi;2002603 said:
I think sometimes this point gets overthought... but the oil cooler is a pretty silly setup overall on our cars and could have been refined better imo. In the end, I want to do a relocated double oil filter (one with a very fine oil filter and one regular Toyota OEM). Im not sure about putting any upgrades into the oil cooler itself because I don't think I run my car hard enough to worry about it.
Toyota engineers put more research into the 7M oil cooler circuit than any forum member I've ever heard of. I think a lot of folks underestimate the resources that go into OEM equipment. Equipping the 7MGTE with an oil cooler circuit cost Toyota a LOT of money. Likely millions upon millions of dollars. OEM finance groups do not allow frivolous equipment unless it's a marketing ploy or something. I very much doubt the 7M oil cooler was solely a marketing ploy.
While a full flow thermostatically controlled oil system is an upgrade over the OEM set-up I think the OEM setup is proof that Toyota was confident in the 7Ms oil supply and pressure. They came to the conclusion that the loss in flow to the engine bearings and overall pressure loss resulting from the cooler circuit, oil pump relief and squirters/filter relief was all worthwhile.
From a reliability standpoint on a near stock GTE, the stock set-up has a HUGE advantage. Consider a leak in the factory cooler lines. That will only leak when the overall system has sufficient pressure. If the system loses pressure, the flow to the cooler stops. You may lose your cooling ability, but the engine still gets oil (until you leak all the oil, obviously). Now consider the full flow upgrade. A leak in that system directly impacts the pressure to the engine. You can quickly have an engine running on no pressure because of an external hose rupture. The factory system never allows for that. The upgraded full flow setup has better performance from a cooling standpoint, but the opportunity for catastrophic failure goes WAY up. Additional hose, fittings, external thermostat, filter adapter, etc.
I'm by no means steering anyone away from a proper full flow circuit, but understand that the factory cooler, while a pressure and flow thief, works well enough for near factory power levels and ensures an external hose leak doesn't lead to complete engine failure. It offers sufficient cooling to allow the 7MGTE to run well for tens of thousands of miles well over the factory power level.
Prioritize your upgrades and keep in mind how little most of us understand these systems compared to the folks that engineered them. To stand a chance of competing with the OEM knowledge on the cooler circuit you'd need to datalog at least a few different temp and pressure instruments in various places throughout the system. I've never seen any forum member or aftermarket company do any kind of research or testing like that on our oil systems.