Thermostat / Transmission Question

[Jkysh]

Have talked to a few folks with stage 2 Gen2s running 93 oct that have the 170 thermostat / reflash and are seeing max CHTs of ~220.

This is ~20/25 degrees lower than I am seeing now and am inclined to get this done as it seems to be worth the minimal effort

 

[New recaros]

Have talked to a few folks with stage 2 Gen2s running 93 oct that have the 170 thermostat / reflash and are seeing max CHTs of ~220.

This is ~20/25 degrees lower than I am seeing now and am inclined to get this done as it seems to be worth the minimal effort

Good luck, your not increasing cooling system heat removal capacity, your just making it go to 100% sooner. Basically just delaying heat soak.

 

[Jkysh]

Good luck, your not increasing cooling system heat removal capacity, your just making it go to 100% sooner. Basically just delaying heat soak.

I understand im not increasing cooling systems capacity, but the reduction in final "max" temperature is what im after. I am considering the 180 thermostat and having my tuner kick my fans on at 185. Id imagine this would provide max numbers roughly around 220-230CHT while keeping my coolant around 210 max.

I have seen a few posts on here stating this 180 thermostat would be best for my climate (northeast ohio) year round and keep my coolant temp well above the preferred minimal requirement of 180 for this engine. What am i missing?

 

[New recaros]

I understand im not increasing cooling systems capacity, but the reduction in final "max" temperature is what im after. I am considering the 180 thermostat and having my tuner kick my fans on at 185. Id imagine this would provide max numbers roughly around 220-230CHT while keeping my coolant around 210 max.

I have seen a few posts on here stating this 180 thermostat would be best for my climate (northeast ohio) year round and keep my coolant temp well above the preferred minimal requirement of 180 for this engine. What am i missing?

Once the thermostat is wide open, no matter the set temp, your system is at 100%. Only adding more air flow or cooler air to the radiator will drop the outlet temperature of the radiator. Or you can reduced the engine load and create less heat. The set points your adjusting makes the system go to this 100% capacity sooner but does not provide increased cooling. Once you reach 100%, increased engine load equates to increased engine and cooling system temperature.
Maybe this might help, your cooling system has a fixed amount of cooling capacity, it is sized for near max engine load. The thermostat is only there for low load conditions so you’re engine does not run to cold.
Increasing water flow helps sometimes but it is because of velocity and better washing of the wetted surfaces in the engine. What happens in this case, the outlet water from the engine is hotter which enters the radiator hotter and outlet of the radiator is also hotter. This increase outlet temp happens because the velocity has increased and residence time inside the radiator drops. Remember the capacity or btu removal capacity of the radiator is already maxed out.
Changing the thermostat and fans can really help on short term loads like off roading, but on long sustained loads as you described, you will not get the results you are looking for.
Like I said, if the thermostat is less restrictive it may lower your temp a bit from increased water flow.
I hate tune-ups in a can, but anti foam really helps. Engine Ice, Redline water wetter, VP cooldown. These are all silicone antifoamers. I use the VP cooldown. What you’re talking about doing should not hurt anything and it’s cheap, so try it. I can see some nice gains under normal driving, but not sustained heavy loads.

 

[Jkysh]

Once the thermostat is wide open, no matter the set temp, your system is at 100%. Only adding more air flow or cooler air to the radiator will drop the outlet temperature of the radiator. Or you can reduced the engine load and create less heat. The set points your adjusting makes the system go to this 100% capacity sooner but does not provide increased cooling. Once you reach 100%, increased engine load equates to increased engine and cooling system temperature.
Maybe this might help, your cooling system has a fixed amount of cooling capacity, it is sized for near max engine load. The thermostat is only there for low load conditions so you’re engine does not run to cold.
Increasing water flow helps sometimes but it is because of velocity and better washing of the wetted surfaces in the engine. What happens in this case, the outlet water from the engine is hotter which enters the radiator hotter and outlet of the radiator is also hotter. This increase outlet temp happens because the velocity has increased and residence time inside the radiator drops. Remember the capacity or btu removal capacity of the radiator is already maxed out.
Changing the thermostat and fans can really help on short term loads like off roading, but on long sustained loads as you described, you will not get the results you are looking for.
Like I said, if the thermostat is less restrictive it may lower your temp a bit from increased water flow.
I hate tune-ups in a can, but anti foam really helps. Engine Ice, Redline water wetter, VP cooldown. These are all silicone antifoamers. I use the VP cooldown. What you’re talking about doing should not hurt anything and it’s cheap, so try it. I can see some nice gains under normal driving, but not sustained heavy loads.

The above makes sense and I appreciate your response - I am new to a tuned gas engine and appreciate your feedback. I am hung up on folks I have talked to showing me photos from their Cobb with the same setup I have, running MAX 190 oil temp, and 190 coolant temp in 100+ texas heat while ripping on their trucks for hour long drives. Does this not equate to actual readings? These folks have the 170 thermostat

 

[New recaros]

You are not comparing apples to apples. First, HP =heat. It don’t take all that much HP to fly around the desert. They are on and off the throttle, turning, assenting and descending hills etc…allowing for cooldown periods. You can go 75 on a flat road and barely touch the pedal. A 100 hp VW can go 75 down most roads. You were climbing massive grades, truck probably shifted to 7 gear, 3000 rpm or so for 15-20 minutes generating sustained HP for long periods. They might of used more peak HP for a minute but a lot less over time.
I have designed, operated, maintained and diagnosed heater exchangers my whole career. The mods that are recommended may very well help under certain driving conditions. but will not help, under the conditions you put forth in your post. If you want to cool a hot engine, turn on the cab heater or just slowdown. Lol
If you have had cam phasers replaced, your thermostat could be sticking due to dirt in the system. If so, replace the thermostat
and coolant. There have been several on here that had elevated temps after cam phaser replacement only to find out the thermostat is stuck.