Bill Verburg

A version of it can be seen here

vjd3

Yes, but my point is, if you add the second cooler for the track, the oil runs cooler all the time, whether you are on the track or not, because you've greatly increased the efficiency of the oil cooling -- like you do if you run the oil cooler fan on high all the time. Which is not a bad thing, in my opinion.

Bull

Thanks Bill, that is similar to the one I was thinking of.

Bull

A properly functioning thermostat will prevent the car from running with the oil "too cool", as some are concerned about, while a second cooler (or manual high-speed fan switch) will prevent the engine from running overly warm. Both are good solutions, although much different in complexity and cost of implementation.

Bill Verburg

In a thermostaticly controlled system as used in a 993 the second cooler just allows the oil to run above but still closer to the set point of the system which is 83*C(181.4*F) more of the time.