160 thermostat

**2002ssslp** · 12-11-2011, 09:14 AM

I am thinking of going to a 160 deg. thermostat for my bolt on modded 02 SS. Do I need to send my computer back to Frost for an upgrade or will the change not matter ?

**Firebirdjones** · 12-11-2011, 09:38 AM

I'd reprogram the fans to work in sink with the thermostat so you reap the full benefit.
It's not necessary, it would run cool while moving, but in traffic the engine would have to heat up to your stock fan "switch on" temps, which is usually around the 220 mark.
Without the fan settings programmed, the engine would see rather large temp swings.

These 160 thermostats actually operate at about 175. They start to open around 172. I found that good fan settings are around the 180-185 range. Frost will know exactly what to do. Hope that helps.

**pajeff02** · 12-11-2011, 12:28 PM

^^ Agree. It's a simple update to the fan settings and I would absolutely do it.

**2ManySS's** · 12-11-2011, 02:59 PM

No reason to do this.
Many articles and testing has been done that shows a temp around 185 is the most desirable for efficient combustion.
A 160 stat could throw codes if it actually opens around 160 and or make it run a tad richer. 180 stat, maybe yes, 160 no reason!

**pajeff02** · 12-11-2011, 06:08 PM

I did go with the 180 degree thermostat in our car and a tune that included modified fan settings. On the scanner (as anything other than a temp gauge in a '98 is an estimator at best) the engine runs 183 to 196 degrees for the most part depending upon speed and load.

**Firebirdjones** · 12-11-2011, 06:22 PM

Originally Posted by 2ManySS's

No reason to do this.
Many articles and testing has been done that shows a temp around 185 is the most desirable for efficient combustion.
A 160 stat could throw codes if it actually opens around 160 and or make it run a tad richer. 180 stat, maybe yes, 160 no reason!

In all actuality, you'll find the LS1 stats don't operate at 160 as they advertise. They are only capable of operating in the 175 range by design. If you test them on the stove and log them in the car (I've done both) you'll find the 160's actually don't even begin to open until 172 degrees. They don't fully open until 175-176ish. So the engine will run in the mid to upper 170's at best but I find that logging it will run 182 most of the time. It doesn't affect the fuel curves either, as the stock tune goes into closed loop at ~90 degrees (or there abouts last time I checked)

I don't buy into the whole "engines are more efficient at this temp" kind of thing. Coming from a racing backround I've found most of my stuff always ran it's best time (and best dyno numbers) with a coolant temp of about 140-150 degrees as long as the oil was warm.
When you start getting things hot, it heats up other things, like fuel and air, both of which affect power. Not to mention cooler running engines also keep under hood temps cooler, which is much easier on plastic and rubber parts. And we all know 4th gens are full of plastic. Also keeps the transmission cooler, and we all know heat is a #1 killer of automatics.
Hotter running thermostats were introduced in the 70's for the sole purpose of emissions compliance and burning off more hydrocarbons.

Those are some of my reasons for a cooler running engine. Take it for what it's worth and do as you wish.

**0rion** · 12-11-2011, 09:04 PM

also keep in mind that 160 is just the advertised opening point for t-stat......your fans is what will dictate where the car will run except at freeway speeds like FBJ said.

**2ManySS's** · 12-12-2011, 03:34 PM

He is not racing the car.
It is not a old school carbed engine.
Everything I have ever read tells me 185+ at min. is the best for a street engine OBD2 system.
OBD2 systems will go richer sub 185.

**Firebirdjones** · 12-12-2011, 03:40 PM

On these 4th gens I can tell you without a doubt, they don't go rich sub 185 temps.

Once they are in closed loop (about 90 degrees) all fueling is controlled by the 02 sensors and the MAF tables. Temps are out of the picture.

Doesn't have to be a carbed engine to make power at cooler temps.

**pajeff02** · 12-12-2011, 03:51 PM

^^ What he said.

**0rion** · 12-12-2011, 07:38 PM

Originally Posted by 2ManySS's

He is not racing the car.
It is not a old school carbed engine.
Everything I have ever read tells me 185+ at min. is the best for a street engine OBD2 system.
OBD2 systems will go richer sub 185.

you have to think of it in generic terms.....engines in general like cold dense charges, carbed or not, to make the most HP. Cooler the air the more of it you get in the cylinder. Hot heads and TB (without the bypass) heat the charge up. At the end of the day though the difference is probably fairly small HP wise but another bonus to having everything cooler is it helps control detonation. Probably what you're reading is more emmission related.....at least that's what I would think.

**Firebirdjones** · 12-13-2011, 06:26 AM

And Orion hits on one main point that I prefer cooler temps. Detonation....

Gas quality continues to get worse, and it's not going to get better. Cooler combustion chambers are the key. To get that, alot of little things help. Things like aluminum heads, cooler plugs, and cooler engine temps all combine to make a high compression engine more tolerable on todays crappy pump gas.
With those cooler temps you can get away with more ignition timing (if the engine likes it) or a more aggressive tune if you will.