Why the 160 degree thermostat?

[DangerZL1]

Should be easy to change, but I think in a previous post that a tune is necessary to prevent throwing a code. Hopefully someone else will clarify this.

[SamHouseIII]

Originally Posted by Mr. iNCREDIBLE

Actually due to EPA efficiency and emission regs most OEMs are rated around 203°

the higher temp makes for better engine efficiency, aka more MPG's

the lower temps make the motor run richer which produces more HP but less MPG.

I would have to check the actual thermostat for sure, I read somewhere 180, in the service manual states;

1. Use a J 24731 - Tempil Stick in order to find the opening and the closing temperatures of the coolant thermostat.

• 1. The 188 tempil stick melts at 87°C (188°F). The thermostat should begin to open.
  • The 206 tempil stick melts at 97°C (206°F). The thermostat should be fully open.

1. Replace the coolant thermostat if it does not operate properly between this temperature range.

http://www.motorward.com/2012/10/joh...ro-zl1-hpe700/#

Link to Hennessey.....most shops do use the 160 temp thermo, however they are also programing the cooling fans to come on earlier/lower temp...

[hognutz]

one thing people always forget about switching T-stat is if you do not alter your fan setpoints you don't get full benefit.

At low speed when you need your fans to maintain temp if they come on too late you 160 t stat does not help at all. you will just gain temp until you get to your fan on point and your fan will only pull it down to the off point.

Many people do not implement the lower temp thermostats correcly because they don't want to tune. If you not willing to tune you need to take manual control of your fans to really get the benefit of it.

[Blown355]

Originally Posted by DangerZL1

Should be easy to change, but I think in a previous post that a tune is necessary to prevent throwing a code. Hopefully someone else will clarify this.

That is correct. It will throw a code "if" the ecu doesn't see coolant tempsof at least 167 degrees after ~7 minutes of runtime. I had to let my car idle for 5 minutes before driving it in the mornings or it would throw a code (and disable the a/c). This was in Texas, in the summer. I finally got tired of having to bring my laptop with me every morning just to clear the code so my a/c would work, so I put an 180 degree thermostat in.
Just an FYI.

[ZO6 Bryan]

I agree with everything ********** said but would add this. The hot mod to do when the factory thermostats were 195 deg to get better emmisions in the late 70's thru the early 90's was to swap in a 180 deg. thermostat. Then the reverse cooled LT1's came in '93 and they had 180 deg. thermostats from the factory. Because they are reverse cooled they needed a cooler thermostat to warm up to 190 deg at the valve head. So then everyone started putting 160 deg thermostats in the LT1's because that would make the car run at 180 deg at the valve head. Now emmissions are better controlled on the LS engines since '98. And they came with 180 deg thermostats from the factory. Which is as cool as you really should need.

[BAD ZL1]

Originally Posted by G-Oil Guy

wow...really?

The 160 T-Stat, as OneSlow said, allows the T-stat to open sooner. This lets the engine coolant circulate through the heat exchanger soon. This leads to lower coolant temps, which leads to lower running engine temps which leads to reduced heat soak which leads to better engine performance.

ALSO reduces the risk/chance of overheating.

Nice sarcasm with the "wow really"...lol. Read further in this posting and you are basically wrong on all accounts. A T stat that opens sooner makes a motor get to operating temp slower, which has zero to do with lower coolant temps, lower running engine temps, and reduced heat soak...none of which has anything to do with reduced risk of overheating..Thanks for the lesson

[tramtwo]

just get some wetter water... I had a tuned setup with a 160 t stat and after a lot of back and forth on this site I don't think it is a good mod for these engines... you can search... plenty posting on the subject by some really smart engine guys.... the debate is split right now the middle some swear by em some think they actually cause premature engine wear problems

[tomster]

On A zl1 you will also benefit from having the cooling fans turn on soomer which will help to cool the heat ex-changer better. FYI you HAVE TO RETUNE to see the gains here. Also if you dont tune you will get a ses light after 3 drive cycles of engine not at operating temp.

[itsadryheat79]

In hot climates like AZ and with the AC on the radiator fans are always running anyway. The key to cooling I've found is flow both air and water. Fan shrouds are a must. The shroud system has to be efficient for idle or low MPH air flow with baffles allowing for more airflow when the fan itself becomes an obstacle at higher MPH.

In a heat exchange flow system a lower T-Stat can make the water always flow and always be hotter than what you'd want. Systems are engineered to be more efficient by allowing the T-stat to restrict water flow. This restriction will suspend the water in the radiator allowing it cool down before it returns to the engine. Generally this engineered restriction efficiency is why it's never a good idea to pullout the T-stat completely.

[Mr. iNCREDIBLE]

Originally Posted by SamHouseIII

I would have to check the actual thermostat for sure, I read somewhere 180, in the service manual states;

1. Use a J 24731 - Tempil Stick in order to find the opening and the closing temperatures of the coolant thermostat.

• 1. The 188 tempil stick melts at 87°C (188°F). The thermostat should begin to open.
  • The 206 tempil stick melts at 97°C (206°F). The thermostat should be fully open.

1. Replace the coolant thermostat if it does not operate properly between this temperature range.

http://www.motorward.com/2012/10/joh...ro-zl1-hpe700/#

Link to Hennessey.....most shops do use the 160 temp thermo, however they are also programing the cooling fans to come on earlier/lower temp...

no I wasn't talking specifically about the Camaro, it might be a 180° I never actually checked, I was speaking in generals, the majority of vehicles, especially the grocery getter 4-bangers are 203° - 225°

your original statement was "most stocks" I took that to mean most cars in general.

[SamHouseIII]

Originally Posted by Mr. iNCREDIBLE

no I wasn't talking specifically about the Camaro, it might be a 180° I never actually checked, I was speaking in generals, the majority of vehicles, especially the grocery getter 4-bangers are 203° - 225°

your original statement was "most stocks" I took that to mean most cars in general.

no worries