Mongo

I know someone is going to point the finger at me and say "wrong" for this.... lower temp thermostat? IT has kept engine temps down while in motion for me. I also had the cooling flaps disabled on my car by pulling the fuse to leave them open. I don't think the OB cars have them though. You could do a 599 GTO mod to your hood too...

Ducman82

when i get to the body work on my car, i dont mind the idea of hood louvers. i like Marks set up.

UncleMaz

I have a 931 hood on my 944 for venting. I would consider grafting a couple of those (Naca duct) in. I like Mark K's setup too.

danglerb

Thermostat sets the lower limit to the normal operating temperature, and has nothing to do with the upper limit except time delay as the temp rises when the cooling capacity is exceeded.

If your cooling capacity, radiator and airflow, aren't big enough then the engine temperature is going to wander up and down at some point above the thermostat setting. Optimal A/F and timing change as the engine temp changes, so this is not good.

The "real" under hood heat problem is heat soak post shut down, thats where peak temperatures occur, and I don't see the thermostat having any effect on that.