# 160 thermostat? yes or no?



## Bossin (Jul 27, 2011)

gasket leaking coolant so i mite as well change the thermostat wondering if i should go with the slp 160 or the 186 oem


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## Falco21 (May 11, 2010)

Go OEM. There was a thread recently on the problems involved with the aftermarket thermostat. The OEM one works great. I had the 160 and was running into problems with it. Switched back to the OEM and it has worked flawlessly.

Here you go:

http://www.gtoforum.com/f37/bout-fried-my-motor-last-week-vacation-34892/


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## Bossin (Jul 27, 2011)

thanks man good too know , that sounded like a big hassle


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## jetstang (Nov 5, 2008)

Lower temps make more HP. Check with SLP for additional mods for that stat.


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## Falco21 (May 11, 2010)

It can be dangerous if you are not paying attention. Honestly, the benefit is not worth it.


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## jetstang (Nov 5, 2008)

The lower temp will make more HP. I don't know where the choke kicks off at, so it may cost some MPG, but will not damage anything.. Your heat won't work as well, so probably the wrong time of year to do it. A 180 is a nice compromise.


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## Falco21 (May 11, 2010)

Well in essence it does create more power by allowing more timing, but these engines were made to run when warm. 160 just seemed way too cool for me. I know many that have gone back to the stock thermostat due to problems with the 160 or just because they felt it was too cool to run. Also, in order for the 160 to work properly, the fans would need to be adjusted to come on at the right time in accordance to the thermostat.

Colder temps does make more power, but it does also sacrifice mileage and emissions. OP, if you feel the need to lower the temps, go for a 180 degree thermostat. It's 6 degrees lower than stock, but not as low as the 160.


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## 87GN06GTO07IRL (Aug 10, 2009)

I use a 160 and the temp stays at 180 all the time. I wouldn't switch back to stock.


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## LS2 MN6 (Jul 14, 2010)

This is a hot topic, on older engines for sure lower the Tstat to run colder.

New engines are designed for the stock tstat, it really isn't best to change them unless you redesign the system.

The easy things are reprogramming the fans, the harder thing is getting the oil to a proper level or the engine at a proper operating temp. By switching to a 160 tstat you will actually cause your engine to perform worse (even if it makes a few more HP the efficiency level of the engine has dropped). Emissions and fuel economy will suffer.

A good tune with a stock tstat, is much better than a quick tune with a 160.


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## RJ_05GTO (Jul 6, 2008)

Bossin said:


> gasket leaking coolant so i mite as well change the thermostat wondering if i should go with the slp 160 or the 186 oem


No. Reprogram the fans for the stock thermostat. I have my fans on at 210 instead of the 235 stock temp. There was a whole wright up somewhere that the 160 thermostat in aluminium engines actually cause damage over a period of time because of the looser tolerances they have to run in order to compensate for the thermal growth of the parts. But lots of people run them without any known issues but im going to stick with my stock stat.


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## LS2 MN6 (Jul 14, 2010)

RJ_05GTO said:


> No. Reprogram the fans for the stock thermostat. I have my fans on at 210 instead of the 235 stock temp. There was a whole wright up somewhere that the 160 thermostat in aluminium engines actually cause damage over a period of time because of the looser tolerances they have to run in order to compensate for the thermal growth of the parts. But lots of people run them without any known issues but im going to stick with my stock stat.


:agree


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## Mike_V (Mar 10, 2006)

I've had no problems. What it comes to is that small mark right before mid point on the temp gauge. Looking at the temp, as said already, I run 180.


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## svede1212 (Nov 1, 2005)

Mike_V said:


> I've had no problems. What it comes to is that small mark right before mid point on the temp gauge. Looking at the temp, as said already, I run 180.


180* isn't a fully warmed up motor but anyways if you're checking your temps with the temp gauge good luck. It doesn't move between 17x*-21x*. It's more like an on/off switch than a gauge. You need to do the magical "set-mode" while turning on key trick to see a accurate number without a logger. Adjusting the fans I run 194* with the stock stat. There will be no noticeable difference in seat of pants or dyno HP or ET with a slightly lower temp on a normal car. One with different heads and bumped compression or FI may benefit a little with more timing


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## dustyminpin (Jun 19, 2006)

I had the SLP, as earlier stated in the above link, and it failed on me after only being in the car 15 months, and at the worst possible time, Chicago rush hour traffic. According to my Garmin Ecoroute HD obd2 blue tooth gauges, I was running at 180ish with the SLP stat. Now that I have a brand new OEM one back in, it's running at 197ish. That 30 dollar SLP stat could've cost me my motor or warped the heads. I'm sticking with the 13 dollar stocker. I called my tuner after this happened and he said stick with the stocker as well. I'm not a big fan of SLP anyways, but if you insist on a 160 degree stat, there are a few other brands out there.


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## Mike_V (Mar 10, 2006)

svede1212 said:


> 180* isn't a fully warmed up motor but anyways if you're checking your temps with the temp gauge good luck. It doesn't move between 17x*-21x*. It's more like an on/off switch than a gauge. You need to do the magical "set-mode" while turning on key trick to see a accurate number without a logger. Adjusting the fans I run 194* with the stock stat. There will be no noticeable difference in seat of pants or dyno HP or ET with a slightly lower temp on a normal car. One with different heads and bumped compression or FI may benefit a little with more timing


No, I'm saying that's where the temp gauge stops - just for reference. I have the dual Aeroforce gauges to watch the temp. The fan temp is set to whatever tune SLP loaded, but what I get to is 180. I don't know if it's better, worse, or whatever else, but the car runs like :willy: Prior to the change, I did notice a huge drop in power on hot days, but I only put 800 miles on it before the change.


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## BlackJackByte (Aug 31, 2009)

I have a friend (I know...doesn't everyone), my best friend actually, who worked as an engineer at Jasper engines and then later went to work for Cummins, builds drag cars as a hobby blah blah blah. Anyways, when I asked him about ayear ago on some mods for the goat, he mentioned two "bad ideas"...SLP Underdrive pulley and the SLP 160degree thermostat. His reasoning is that GM had the motors designed to run at that operating temp for a reason and changing it like that will only incur problems, besides SLP is only slightly better than stock and is priced like parts were forged by God himself.


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## svede1212 (Nov 1, 2005)

Mike_V said:


> No, I'm saying that's where the temp gauge stops - just for reference. I have the dual Aeroforce gauges to watch the temp. The fan temp is set to whatever tune SLP loaded, but what I get to is 180. I don't know if it's better, worse, or whatever else, but the car runs like :willy: Prior to the change, I did notice a huge drop in power on hot days, but I only put 800 miles on it before the change.


Cool (punny huh?). Air temps can greatly affect power. You're not going to see that with a 12-14* lower coolant temp tho. The computer uses air and coolant temps for various things like fueling. At high air flow like WOT the biasing shifts strongly to air temp as the air is spending significantly less time in the engine so a small coolant temp difference has little affect.


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## Mike_V (Mar 10, 2006)

Uhoh - I have the UD and 160. 

I'd like to get the air temps down, but I can say the heat from the front is not what it was. If you had a full intake that just replaced the stock cover - I'd be all over that. Not just for cooler air temps, but that little vent leading to the filter box always shocked me. The area is some minor fraction of the filter size, and the little elbow seems even smaller.

I'm just not one to keep messing with a car when it's acting great. The SLP stuff gave me a minor boost that seems safe, but the entire intake system is a garbage design.


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## 1224GTO (Sep 18, 2011)

*SLP 160 Tstat*

I put one in 2 months ago i can notice a power loss now i know before i went to the 160 it had a better Take off at lights and i'm getting 17.2 mpg i used to get 18.2 mpg i also put a K&N in .. I think i'm going to put the stock stat back in, i got the slp stat because i'm in Florida and it seemed to run kinda hot i also removed the rubber ram air hood inserts for better air circulation.


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## 1224GTO (Sep 18, 2011)

*SLP 160 Tstat*

would the stat cause a loss in power ?? :confused


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## Falco21 (May 11, 2010)

1224GTO said:


> would the stat cause a loss in power ?? :confused


Did you re calibrate the fans after the install? If the engine is running to cold, it can lead to a significant power loss. The PCM will go into a reduced power mode due to the temperatures not being high enough.


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## 1224GTO (Sep 18, 2011)

No i didnt miss with the fans stock settings...


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