I put in a 160* thermostat a few months ago thinking that it would help with the additional heat of a front mount turbo kit (still NA at the moment), and would allow for some additional ignition timing. But I have been reading that these LS motors like to run a little warmer than most, and that running warmer will help with fuel economy.

I'm debating putting in a 180* or the stock thermostat to help with fuel economy. With the 160* thermostat it will run around 172-175F on the highway (it won't run any cooler than this after warmed up) and around 185F in traffic with the e-fans on. With the stock thermostat it would run at 195F on the highway. In my area the average high ranges from 61-77F throughout the year, rarely gets above 90F.

So my question is, in a boosted application, how much benefit is there of a 160* thermostat?
Can timing really be increased a noticeable amount by running 20F cooler?
Does a turbo really add enough extra heat to justify it?
Any other advantages/disadvantages?

Discuss

 

With a NA application you do want to run warmer. Warmer temps = higher cylinder temps = higher cylinder pressure = more power.

However with FI, you will be limited by the detonation limit of the fuel. You avoid detonation at all costs hence the reason people get dished pistons to lower CR, using colder spark plugs, spray methanol, use an intercooler, etc. If there is anything you can do to add some layer of protection from detonation, do it. That includes using a colder thermostat.

 

what he said. im running a 160 stat myself. the temps your truck run are just fine imo

 

I am running one also, have been for years.

 

Same here. Keep it cool, especially with boost.

 

I guess I should get one then. Ive been running the stocker mainly out of laziness lol

 

All the 160's I have seen seem to run around low 170's once they finally open.

 

I run a 160 on both my forced inductions LS motors. I have been running one on my Vette for about 5yrs. It definitely helps with cool down on high speed runs. Also keeps the car a little cooler, so you can keep the run going longer in the first place. When your making 800-900 or more horsepower it generates a lot of heat.

 

Interesting, thanks for the replies. The way I see it is that the thermostat will only control the lowest temp, while the fans control the highest temp, assuming the rest of the system can handle the heat. So a lower thermostat can help the truck be cooler before a run so more heat can be built up during the run. Can anyone throw out some numbers on how much their coolant temp will rise during a run?

As for timing, anyone has experience with how much more timing can be had when running ~20F cooler?

 

It will control the lowest temp while you fans, radiator waterpump, and vehicle speed determine the high temp. Mine usually rises maybe 5 degrees over 1/8th mile. The lowest mine will ever go is 169 cruising on the highway. I wouldnt add any timing just because I have a colder thermostat, I would just leave it as is for extra insurance.