180* vs 160* Hypertech T-stat??
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
CFI-EFI will chime in with his thoughts on this matter.I will beat him to it by saying , once it is open it has no bearing on your running temp.All you are acheiving is a earlier opening.
The running temp is controlled by the airflow through the core.
If you want to lower operating temp then you need to change when the fan(s) cut in and out.
The running temp is controlled by the airflow through the core.
If you want to lower operating temp then you need to change when the fan(s) cut in and out.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by audible
Get many opinions on this issue. 
Someone give me the final word!!!
What should I use???????????????
Thanks,
Audible
Someone give me the final word!!!What should I use???????????????
Thanks,
Audible
rodj,
Good job. You beat me to it in THIS thread.
RACE ON!!!
Melting Slicks
Joined: May 2002
Posts: 2,670
Likes: 4
From: Severna Park MD
Originally Posted by rodj
CFI-EFI will chime in with his thoughts on this matter.I will beat him to it by saying , once it is open it has no bearing on your running temp.All you are acheiving is a earlier opening.
The running temp is controlled by the airflow through the core.
If you want to lower operating temp then you need to change when the fan(s) cut in and out.
The running temp is controlled by the airflow through the core.
If you want to lower operating temp then you need to change when the fan(s) cut in and out.
I'm running a 160 T-Stat with fans on at 195*. In cool weather my engine will run form 165 to 175 degrees, which I find is just on the edge of warm enough for closed loop and correct tune. In hot weather of the summer my engine will run 180 degrees on the highway, and 195 degrees in stop and go traffic. With the A/C on it still doesn't run above 195 unless I get stuck in a traffic jam on a really hot day.
So, except in really hot weather conditions the car will run cooler, maybe too cool for proper tune.
I think I need to change to a 180 T-stat, but I'm waiting until cooler weather to do it.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Originally Posted by FELNGR8
Not entirely true, or not true for all circumstances.
I'm running a 160 T-Stat with fans on at 195*. In cool weather my engine will run form 165 to 175 degrees, which I find is just on the edge of warm enough for closed loop and correct tune. In hot weather of the summer my engine will run 180 degrees on the highway, and 195 degrees in stop and go traffic. With the A/C on it still doesn't run above 195 unless I get stuck in a traffic jam on a really hot day.
So, except in really hot weather conditions the car will run cooler, maybe too cool for proper tune.
I think I need to change to a 180 T-stat, but I'm waiting until cooler weather to do it.
I'm running a 160 T-Stat with fans on at 195*. In cool weather my engine will run form 165 to 175 degrees, which I find is just on the edge of warm enough for closed loop and correct tune. In hot weather of the summer my engine will run 180 degrees on the highway, and 195 degrees in stop and go traffic. With the A/C on it still doesn't run above 195 unless I get stuck in a traffic jam on a really hot day.
So, except in really hot weather conditions the car will run cooler, maybe too cool for proper tune.
I think I need to change to a 180 T-stat, but I'm waiting until cooler weather to do it.
165* engine operation temps are just entirely too low. You may be reaching closed loop, but the oil can't reach temperature.
All I can suggest is replace the 160* stat with 180* and the engine will love you for it.
Instructor
Joined: Jun 2005
Posts: 193
Likes: 0
From: woodinville washington
when i went from a 190* to a 169* my oil temp remained the same, but i agree, too cold is not good for the motor, thats why we warm them up before driving, i also don't see how a lower stat would help performance, i know the motor may run cooler, but i thought the air temp affected performance
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Instructor
Joined: Jun 2005
Posts: 109
Likes: 0
From: New Milford Ct
Also keep in mind that by running a lower temp t-stat, the coolant in the radiator is not given sufficiant chance to cool down properly before the t-stat opens up. In some cases, the t-stat may stay open simply because the engine temp does not go below the t-stat rating, and a constantly open t-stat is not a good thing.
I've run the stock 195* t-stat, and recently changed to a 180* piece. I noticed no change in temps at all. Maybe a couple degrees on the highway, but nothing worth writing home about.
I've run the stock 195* t-stat, and recently changed to a 180* piece. I noticed no change in temps at all. Maybe a couple degrees on the highway, but nothing worth writing home about.
Safety Car
Joined: Nov 2004
Posts: 4,991
Likes: 5
From: The Pines South Jersey
I went with a 180 and couldn't be happier.
With that said, I also went with a 185 fan switch, and both fans operate from it.
My temp never gets to 190, regardless of the driving situation.
I did a complete flush after pulling the rad for a clean up and fin straightening.
And I am running about a 40/60 mix of collant and I added a bottle of water wetter.
With that said, I also went with a 185 fan switch, and both fans operate from it.
My temp never gets to 190, regardless of the driving situation.
I did a complete flush after pulling the rad for a clean up and fin straightening.
And I am running about a 40/60 mix of collant and I added a bottle of water wetter.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Why are you waiting for cooler weather to install the 180 stat? You admit that your coolant runs 180 and 195 in hot weather, this means that your 160 stat is wide open all the time. So what good is a thermostat that is wide open all the time? If you install the 180 stat you should still see 180 and 195 temps and when you are within several degrees of 180, the 180 stat will control the coolant temp.
C4 radiators are sized to maintain 180-195 F over 35 mph, so a 160 stat is a waste of money and installation effort. For the life of me I cannot understand why anyone who understands how auto cooling systems work would want to install a 160 F thermostat.
C4 radiators are sized to maintain 180-195 F over 35 mph, so a 160 stat is a waste of money and installation effort. For the life of me I cannot understand why anyone who understands how auto cooling systems work would want to install a 160 F thermostat.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
audible, as you can plainly see you are still not going to get a difinitive answer on this topic.
You'll just have to read through the opinions and experience and make up your own mind.
But if you change the T-stat temp you also need to change the fan on/off control to match.
Hey, try it and see if you like it; if not, change it back.
You'll just have to read through the opinions and experience and make up your own mind.
But if you change the T-stat temp you also need to change the fan on/off control to match.
Hey, try it and see if you like it; if not, change it back.
Melting Slicks
Joined: May 2002
Posts: 2,670
Likes: 4
From: Severna Park MD
Originally Posted by jfb
Why are you waiting for cooler weather to install the 180 stat?
You admit that your coolant runs 180 and 195 in hot weather, this means that your 160 stat is wide open all the time. So what good is a thermostat that is wide open all the time? If you install the 180 stat you should still see 180 and 195 temps and when you are within several degrees of 180, the 180 stat will control the coolant temp.
C4 radiators are sized to maintain 180-195 F over 35 mph, so a 160 stat is a waste of money and installation effort. For the life of me I cannot understand why anyone who understands how auto cooling systems work would want to install a 160 F thermostat.
C4 radiators are sized to maintain 180-195 F over 35 mph, so a 160 stat is a waste of money and installation effort. For the life of me I cannot understand why anyone who understands how auto cooling systems work would want to install a 160 F thermostat.
Time to enjoy the car. Plenty of time to work on it this fall.
Melting Slicks
Joined: May 2002
Posts: 2,670
Likes: 4
From: Severna Park MD
Originally Posted by jfb
Why are you waiting for cooler weather to install the 180 stat? You admit that your coolant runs 180 and 195 in hot weather, this means that your 160 stat is wide open all the time. So what good is a thermostat that is wide open all the time? If you install the 180 stat you should still see 180 and 195 temps and when you are within several degrees of 180, the 180 stat will control the coolant temp.
C4 radiators are sized to maintain 180-195 F over 35 mph, so a 160 stat is a waste of money and installation effort. For the life of me I cannot understand why anyone who understands how auto cooling systems work would want to install a 160 F thermostat.
C4 radiators are sized to maintain 180-195 F over 35 mph, so a 160 stat is a waste of money and installation effort. For the life of me I cannot understand why anyone who understands how auto cooling systems work would want to install a 160 F thermostat.
Turns out I'm doing more cruising than racing so my needs have changed.
Melting Slicks
Joined: May 2002
Posts: 2,670
Likes: 4
From: Severna Park MD
Originally Posted by cuisinartvette
I've always used 160 stats, eprsonal choice. 160 in the 89, puttin a 170 in the Z. To each their own
Team Owner
Joined: Sep 2001
Posts: 62,139
Likes: 1,728
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Originally Posted by FELNGR8
I think, but can't prove it, that the L98s and other SBCs like the 160 stat more than LT1s. Maybe it's the tuning or all the sensor feedback?
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Originally Posted by FELNGR8
If you are going racing, tuners will you to go with a 160 for better power. That's my case.
Turns out I'm doing more cruising than racing so my needs have changed.
Turns out I'm doing more cruising than racing so my needs have changed.
If I was racing, and almost exclusively so, yes, a 160 stat would be used to keep heat soak down and keep things cooler.
However, if I was doing a mix, or more street with occasional racing, I would get a 180 stat, with a manual fan switch.
The logic is simple, with the 180 stat, the oil gets upto op temp and allows all metals to expand correctly.
With the manual fan, the fans can be cranked up and the coolant temps lowered to regain control of the heat soak issue.
L98s need the same temp settings as an LT1... There is a basic reason for this - they are so much alike, it ain't even funny! Since the aluminum heads arrived in 1986, the L98 has the same basic properties as an LT1 - iron block, aluiminum heads, aluminum pistons.
As such, the divergent metals need the same treatment. If your engine had iron heads, then I would consider - hell, recommend - a 160 stat... the heat loss just isn't there with all that iron. Aluminum cools SO much faster.
Which leads me to the LT5... I would be VERY cautious about putting a 170 stat on one of those motors... It just sounds to me to be a recipe for disaster.
