[justpete]

Originally Posted by bNks334

This is incorrect. In reference to qdot, the goal is to achieve a balance between how much heat can be absorbed from the block and how much can be shed. Those are two separate q-dot calcs. You have one for the radiator and one for the cooling system.

The heat flux into the coolant must be shed via the radiator or temps will climb, that's what I meant by balance. And I'm not including oil cooling at all, just engine cooling and disregarding other thermal rejection pathways.

Originally Posted by bNks334

As you've stated, tuning for more power increases the amount of heat the engine is producing. Improving the delta of inlet and outlet temps of the radiator will not help improve how much heat can be removed from the engine block via the cooling system. If you were indeed able to shed more heat from high oil temps into the water, then yes, you'd want to also increase the radiator capacity to handle it. To achieve balance with just a larger radiator, you would need to run the electionic water pump faster or switch to distilled water which transfers heat better than coolant. Again, data does not support that the stock coolant system is an issue in the first place (for all but the most hardcore 30min+ track sessions). Yes, there is a place for improved water cooling, but only after you've tackled the engine oil temps which will throw you into limp mode long before the coolant ever gets "too hot."

A better radiator will drop the coolant temp farther and allow the thermostat to maintain temp otherwise increased thermal rejection from the block to the coolant would cause the temp to rise beyond normal. Anyone who's had a compromised radiator knows opening the heater to coolant flow will drop the temps.

Originally Posted by bNks334

You are literally saying the opposite as feuer here. I agree with feuer when he says oil temps must be above 100c at a minimum (212f). This is the boiling point of water. The boiling point is probably even higher due to the pressure the oil is subjected to. If you run an oil bypass valve, or a lower thermostat, you risk operating the oil too cold. Your oil will never hit that minimum 100c needed to boil water out of the oil. This is more gear toward dual purpose cars since we all know oil will quickly rise over 100c on track even with a bypass valve.

A bypass thermostat is one that recircs the oil back to the engine and gradually with increasing temp allows an increasing amount of the flow to pass through the downstream oil cooler. It doesn't bypass anything but the oil cooler, iow.

Originally Posted by bNks334

Stock thermostat is best. 230f to 260f is an ideal operating range for synthetic oil and engine performance.

Pretty sure no one said otherwise.