Theoretically it should, practically it does as long as you are either moving or reset the fan thresholds somehow (and of course your radiator has sufficient size, airflow and water flow for your engine's thermal output and your ambient).

A lower water temp will increase the thermal transfer in the engine but reduce it at the radiator.

What am I missing/misunderstanding Bryan?

 

How does a tstat that opens sooner make the engine run cooler when the actual cooling system stays the same size?

 

Because the cooling system has spare capacity (assuming what I put in brackets in the previous post is true) which you make use of by a thermostat that is open more often...

Are you finding different? If so, very heavy tuning on a standard radiator in a very hot climate might explain why you see no drop with a thermostat change?

 

Under heavy driving, the tstat is usually open right? So what difference would a tstat that opens at X temp and a tstat that opens at a lower X temp do to engine cooling?

The only thing I can think of that a tstat that opens at a lower temp would do is take longer for your motor to warm up on a cold start, or have a hard time ever coming up to normal operating temp in normal driving (like the issue the OP is having).

Maybe I am missing something here... I just am not grasping the performance/cooling advantage with this.

 

No, it isn't usually open in heavy driving, again with the assumptions I put in brackets. It will be opening and closing (or more likely partially open) depending on the temperature on the stat. There is a range over which they open gradually, hence why a 71C stat doesn't give you a 71C water temp, but several degrees higher.

With a cooler stat on my last car it warmed up just as quickly, but the water temperatures were cooler on cruise or on sustained full load. This gave lower levels of knock activity when the car was driven hard - for a given octane and air temp I could run it with more ignition or boost for longer before things deteriorated. A desirable side effect was lower oil temperatures, but this engine had no air-oil cooler but a water-oil cooler.

On most cars if you have a hole in the thermostat or a stuck open thermostat then even when driven hard it doesn't get up to normal temperatures - again I'm talking a cooler climate than yours? Depends on the spare capacity in your cooling system.

 

Ok I understand what you are saying now.

However I think in circuit driving it would offer no advantage.

 

The thermostat is actually a temperature control device. It will vary the amount of opening to maintain the target temperature that it was built to maintain.

I can see the value in using a lower temp tstat for dedicated race use with an appropriately good radiator, but I don't see the value for a street driven car.

 

What is your objective in the first place?

 

peole do the cooler t-stat mod on honda s2000s together with the fan switch. They notice better performance coming from the richer car and increase in ignition advance (meaused with OBD2 scanner). On a stock honda the fans start at 105 degrees C. On the Evo at 86 (EDM IX). With the aftermarket Tstat and fan switch an s2000 starts the fans at 80 degrees C. There is a noticeable difference in performance which made me think why people dont do this on an Evo. Ralliart makes a 76 and a 71 degree tstat. The stock one is 80.

 

Great conversation guys. Hmm, speaking of a fan switch, is one that can be purchased that spins that fan at lower temps? Installing that should offset the lower tstat to begin with.