# 160 Thermostat



## cpowell (Mar 1, 2007)

Who makes a good 160 degree thermostat. all i have found so far is SLP and i was wondering who else makes tham and how good they are


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## Rukee (Feb 8, 2007)

I`ve said this a couple times now, this time I`ll pose it as a question.
Why would you want a 160* thermostat?? 
The computer will feed the engine an increased amount of fuel in a 'choke' mode until it reaches normal range. If the engine never reaches that normal range then you`ll just be running around with the engine running extra rich causing gas mileage to drop. Plus the higher the engine temp the more efficient the engine burns the fuel. Not to mention the fact the heater and defroster will not work as good, or be as warm as it should. I could see this adding a couple horse on a dyno run, but I wouldn`t put it on an everyday driver. If it`s just the extra fuel that`s wanted, I wonder if a guy could just fool the computer into thinking it`s running at 160* when in fact it`s at it`s normal 190*. Add or subtract resistance to the temp sensor accordingly. That way you could get your increased fuel curve but still have the burning efficiancy of normal opperating temps. just thinking out loud...


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## Verdoro 68 (Dec 27, 2005)

I have an SLP 160 in my car. IMO all the 160s are basically the same. I had my car tuned accordingly so the fans come on sooner and the computer is aware of the change. I used to run around 200-205 degrees, but now I usually run 175-185 degrees.

I installed it primarlily so I could keep my car cooler between runs at the track. The heat kills my times and I'm trying anything an everything to minimize the problem. Between the thermostat and my coated headers I definitely notice that the car cools down a lot quicker.

I also installed a faster reacting air intake temp thermistor from Omega instruments. I haven't had a chance to run it with HP Tuners hooked up yet to see if it makes a difference, but with the track temps ~100 like they have been lately, I figured for $15 it was worth a shot.


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## pickinfights (Oct 3, 2006)

This is another case of, If it's that much better why didn't the manufacturer of the car do it? Just like the cold air intake.


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## PEARL JAM (Sep 6, 2005)

Factory air intakes are made with noise reduction as a priority, not performance.


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## pickinfights (Oct 3, 2006)

:willy: Ohhh god here we go again. GIVE ME PROOF!!!!!!!
I think after my sweet cold air intake, an optima battery, aftermarket spark plug wires, 160* thermo, and a couple of gallons of octane booster, I should be putting out like 500 horse.:willy: :willy:


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## PEARL JAM (Sep 6, 2005)

Wait. Wait................STP octain boost or that 104 stuff with the flames on the bottle?


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## pickinfights (Oct 3, 2006)

You kiddin me... The flames!! Of course.


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## Verdoro 68 (Dec 27, 2005)

pickinfights said:


> This is another case of, If it's that much better why didn't the manufacturer of the car do it? Just like the cold air intake.



I agree that most bolt on mods are seriously overrated, but you could push your argument for anything performance related. How come these cars don't have headers from the factory? The stock manifolds must be better.:willy:


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## GM4life (Mar 18, 2007)

Verdoro 68 said:


> I agree that most bolt on mods are seriously overrated, but you could push your argument for anything performance related. How come these cars don't have headers from the factory? The stock manifolds must be better.:willy:


People get disappointed when they add bolt ons and expect big gains and they don't. People don't realize that modern engines are built really good from the factory. Also bolt-ons don't shine until you add more mods in the future, like cam, FI, ect. Factory headers are not that bad for stock and mild modded engines.


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## kwiktsi (Apr 5, 2006)

pickinfights said:


> This is another case of, If it's that much better why didn't the manufacturer of the car do it? Just like the cold air intake.


Now this is funny . I guess I should sell my turbos, 3" exhaust, blah blah blah- because if making 800+ whp was better, it would have come like that from the factory .

The 160 thermostat has been debated for years- some feel it will lead to a bit more power (though not really noticeable "seat of the pants" wise), others feel that the hotter temps will lead to a more efficient burn and make more power. I personally feel that running in the 180* range is ideal, which it where it actually does run with the 160* stat.

The problem with running a 160, at least in an 05-06 is that the ECU does not have the ability to have the fans cycled on/off below 192, so your temps with a 160 will vary greatly- high 160's while cruising on a cooler day, 190+ sitting at a light. Not that it is going to hurt anything, but it is an "issue".

As for "who make a good 160* thermostat, there is no difference- just get one. The LS1/2 thermostat is a bit more involved than a generic thermostat is to make, so anyone who offers one- it is going to be good . I wouldn't doubt that they all come from the same place anyway.

Lastly- it will not keep the car in "choke mode", where do you guys come up with this stuff? There is no "choke mode". There is open and closed loop and then fueling adjustments based on engine temps, air temps, load, run time, etc. The thing you may be thinking is on some older EFI cars, if the temps were too low, it would keep the car in open loop since it had to be above a certain temp to enable closed loop. The same is true with the LSx cars and all other modern cars but the tune on the LS2 GTO (and I'm sure most other modern OBD2 cars) kicks it into closed loop at around 131*, so unless you are running below that, there is nothing to worry about.

Hope this helps some .
Joe


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## Rukee (Feb 8, 2007)

It has always been my experience with FI vehicles with 160* thermostats and can be verified with a snap-on solus scan tool that they run rich (thus prompting me to use the 'choke mode' phrase to simply terms). Major complaints from customers is poor fuel millage.
I can see it used in a case like *Verdoro 68* uses it for a race vehicle, but again, I wouldn`t recommend it for a daily driver unless your able to tune the computer for it.


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## kwiktsi (Apr 5, 2006)

Rukee said:


> It has always been my experience with FI vehicles with 160* thermostats and can be verified with a snap-on solus scan tool that they run rich (thus prompting me to use the 'choke mode' phrase to simply terms). Major complaints from customers is poor fuel millage.
> I can see it used in a case like *Verdoro 68* uses it for a race vehicle, but again, I wouldn`t recommend it for a daily driver unless your able to tune the computer for it.


Cooler temps require more fuel, which would be the only reason that fuel economy would suffer a bit. As for the scan tool verifying it- what are you "seeing" with the scan tool that is indicating the car is running rich and what year/model vehicles are you referring to? If you are looking at just 02 voltages, that is not indicator of the car running rich. If you are looking at commanded AFR- you will see that it is *commanding* a 14.7:1 AFR any time it is in closed loop, so unless the temps are low enough to keep it out of closed loop, there should be no signs of the car running excessively rich. 
Joe


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## Rukee (Feb 8, 2007)

kwiktsi said:


> Cooler temps require more fuel, which would be the only reason that fuel economy would suffer a bit.


Pretty much what I`ve said already.


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## kwiktsi (Apr 5, 2006)

No, you said that it keeps it in choke mode, adding more fuel- this is not true . It is no different than driving the car on a cooler day compared to a hot day. A colder thermostat does nothing to screw with the ECU as long as it is reaching whatever temps the ECU is programmed to go into closed loop at- which is what I took your post to imply since you said it had to be tuned for the colder thermostat.

Also, like many other things, the cooler temps in themselves may not gain you much- but they do allow for other things that will like more timing without detonating, more aggressive fueling, etc.
Joe


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## Rukee (Feb 8, 2007)

kwiktsi said:


> No, you said that it keeps it in choke mode, adding more fuel- this is not true .







kwiktsi said:


> Cooler temps require more fuel, which would be the only reason that fuel economy would suffer a bit.


You said it yourself. I don`t have to explain what happens, all I know is every FI vehicle I`ve seen with a 160* thermostat has suffered from poor millage.
If it`s using more fuel, then it must be running rich(er), if it wasn`t, it would get it`s normal gas millage. If the new GTO`s are able to tune the computer to the new lower temp, awesome. That has not been my experience with any other FI vehicle.


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## kwiktsi (Apr 5, 2006)

Rukee said:


> You said it yourself. I don`t have to explain what happens, all I know is every FI vehicle I`ve seen with a 160* thermostat has suffered from poor millage.
> If it`s using more fuel, then it must be running rich(er), if it wasn`t, it would get it`s normal gas millage. If the new GTO`s are able to tune the computer to the new lower temp, awesome. That has not been my experience with any other FI vehicle.


I think we are misunderstanding each other- more fuel use with lower temps is normal, not a "tuning" issue, just like your fuel economy suffers in the winter (aside from the oxygenated fuel). It is not running *richer*, the AFR is the same because the fuel demand to maintain that AFR goes up. The decrease in fuel economy is minimal at best though. 

If you are seeing poor economy and an actual *verified rich* mixture (not just using more fuel, but keeping the same AFR- actual measured AFR being rich), then this may be with vehicles that had a T-Stat that maintained temps BELOW the closed loop switchover (Tuned Port cars come to mind). Another time you will get poor running with low coolant temp readings is if the coolant temp sensor is faulty and showing it is colder than it really is and fueling it for the temp it "thinks" it's running (obviously).

Just to mention- this isn't meant to be an argument with you and I hope there are no hard feelings, I'm just correcting some misinformation that is being spread to the original poster and other readers. As long as you are over 131* with the GTO, it is using O2 feedback and it should be trying to maintain a 14.7:1 AFR.


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## kwiktsi (Apr 5, 2006)

Rukee said:


> The computer will feed the engine an increased amount of fuel in a 'choke' mode until it reaches normal range. If the engine never reaches that normal range then you`ll just be running around with the engine running *extra rich* causing gas mileage to drop.



This is what I was referring to- you said it would be in "choke mode" and "extra rich"- neither are true, then you are quoting me saying cooler temps require more fuel to maintain the same AFR as me saying the same thing. They are two different things- using more fuel to maintain the same AFR based on temps, load, altitude, etc. are not making it rich or lean- it is the same mixture, just using more or less fuel to achieve it. The computer is not in any special mode and the fuel mixture is not rich- if you measured it with a wideband, the fuel mixture should remain the same (given that the car is in fact going into closed loop).
Joe


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