rmp

really any better than stock thermostat?

Steve Germany

160 is a little cold for my liking. The whole idea is to keep the air density as high as possible (more air more power). Higher temps start the cat sooner and get rid of residual water sooner - good things! Lowering the engine temp will slightly increase the air density. The standard intake and air flow has not been identified as key limitation for the stock LS2 so I doubt that the thermostat temp will make much of a difference.

BobILoveAVette

Seems like when cars overheated in the summer putting in a lower temperature thermostat would keep you out of problems. I haven't run into that issue since C3s.

not08crmanymore

I am not putting one in because I heard a while ago it turns the oil to sludge in a hurry!True or not,i don't think there's much to gain putting one in.As a matter of fact,MY CAR IS FRIGGIN PERFECT AS IT IS!!! Tha *** end always wants to slide sideways or something when i punch it!!

cbrf4i1

one of the best thing you can do for your c6...don't know any one that is making at lease 50 hp more than stock without one. colder air = more oxygen module = more hp/tq.

Harold Wilson

True colder air has more air molecules. 160 degree air has 4.9% more air molecules in it than 190 degree air at the same pressure. But how does the coolant cool or heat the incoming air or does it? Even if it does get cooled in order to take advantage of the denser air, more fuel is needed to get more power or you'll go lean. Since the mass flow sensor is located in the throttle body, the fuel is adjusted based on the air density before it is cooled or heated by the 160 or 190 degree coolant.

Does anybody have any conclusive data? Like dyno results before and after a thermostat change?

cbrf4i1

mass air / iat is located before the tb so your ecm/pcm will adjustment the fuel curve for whatever the change. you can find out for yourself without taking anyone's word for it on a dyno. put in 160 and your dic will show around 180 or so, run your car at your local track...track your mph...then purposely let your car heat up to 205 (this is what it will show with stock stat) or so and make another run....and compare your trap speed. you will find out for yourself. like i said, i don't know any one that has added at least 50 more hp to his/her c6 that doesn't have a cooler stat for one reason or another...the one that tells you other wise are pretty much stock cars offering his/her opion w/o actually trying it out first. try it out for yourself and find the truth.

LS1LT1

Not



Also don't forget that it's not just the 160* thermostat by itself that helps, ine must also have their fan settings adjusted (LS2 Edit/HP Tuners etc.) accordingly as well.
A company such as Cartek (www.cartek.net) can help with this and other mods.

shopdog

Sludge could be a problem if you drove mostly short trips, so the car never has a chance to warm up. But if the car has a chance to get up to operating temperature (and that temperature won't be 160 degrees), sludge formation shouldn't be a problem.

The longer warm up time does mean it'll take a couple minutes longer from a cold start for the oil to heat up enough so it is safe to get on the car hard. It also means a couple more minutes before the heater will do you any good.

The thing you have to understand is that the engine will stabilize at a temperature that's a function of load and cooling capacity. Cooling capacity is fixed by the size of the radiator and the airflow through it. Engine load is demand based, of course, so the harder you drive, the more heat the cooling system has to reject to achieve equilibrium.

The thermostat doesn't have any role in this after it opens. It doesn't matter if it opens at 160 degrees or 187 degrees, the stock engine is going to reach an equilibrium temperature in the mid-190s at light loads and high airflows, and the equilibrium temperature will be on the order of 230 degrees at very high loads or low airflows. This is the result of design decisions Chevy made when they sized the radiator and the opening through which it receives cooling air. (Also when the fan kicks on if you aren't moving.)

To materially change the equilibrium temperature, you'd have to increase the size of the radiator, increase airflow through it, or reduce engine demand. Since the latter isn't a performance goal, a bigger radiator or more airflow are the only ways to get engine temperatures down from the stock equilibrium points. Changing thermostats, or even removing the thermostat entirely, won't change the equilibrium temperature.

Now it is certainly true that cold air is denser than hot air. Denser air means more oxygen can get into the engine on each intake stroke, which means you can burn more fuel, and thus make more power. This is why cold air induction systems work. It is a (very) minor form of supercharging.

Ok, fine, cold air is good, but how much will the engine's coolant temperature affect intake air temperature. With cold air induction, the answer is practically not at all. At 6000 RPM, any given cylinder full of air only spends 2 hundredths of a second in the engine (from air cleaner to tailpipe). Very little heat can be transferred to the intake air by conduction or radiation from the intake manifold in such a short time. IAT readings show this.

The rate of heat flow is a function of the difference in temperature between source and sink. Most of the heat transfer to intake air occurs at the intake valve, which runs much hotter than engine coolant because it is in direct contact with combustion gases. Changing coolant temperature by a few degrees won't materially change the high temperature of the valve head.

So lowering the engine coolant temperature won't materially affect intake air temperature unless the air is being drawn from the engine compartment, where it has dwelled long enough to pick up significant amounts of heat.

cbrf4i1

mid 190's? maybe for a stock or near stock car with stock stat ...my never see 190 in high airflow situation. 160 stat opens and dic will show around 178...keep in mind temp showing on dic is taking at a different spot than the stat. for my car as long as the car is moving (high air flow per your definition) it will stay see between 176-180 (outside air temp below 85 degree) which tells me the stat is still cycling close and open and the coolant system is still capable of cooling at this temperature...so it never reach the equilibrium temp that you are refering to...sure if i let the car set for 30 minutes and didn't adjust the fan setting it will reach the equilibrium point that you refer to. like i said, everyone has an opion but not everyone is speaking from actual experience from the car he/she is talking about. why do you think with the weather much cooler now all these people are reporting the cars are making much more power and the a$$ is breaking lose left and right..sure some are from the tires not heating up yet...do a poll and see what is the normal crusing temp (high air flow situation) on dic for cf members that has install 160 stat. heat is a reason any car is faster when it first warms up compares to if the car has been stucked in bumper to bumber traffic for extended period of time...... just put in the 160 stat and go to the track and the truth will show itself. no bs or i heard so and so bs either. people with fast car makes more heat will get cooler stat / change fan setting to get rid of heat...

lagogarda

Mobil 1 Synthetic turn to sludge???? First I've ever heard of such a thing under any circumstance.

cbrf4i1

yup, how true, someone better tell these car manufactures to stop using intercooler for their turbo / supercharge cars. there is no way intercoolers would work since air only spend such shortime between the air filter and the tailpipe and stop ripping off the customers with useless parts for as long as intercooler has been around.

higher stat will have higher underhood temperature, where does the air filter get the air from (unless you have a bottom feeder, of course)? oh yeah, under the hood....sounds like the stock car guys / gals don't want your car to be any faster............

rmp

I guess what concerns me is why GM just didn't install the 160 degree thermostat in the first place if it was beneficial to performance; there must be some down side, ?emissions???

cbrf4i1

yup, it burns cleaner. if you want best emissions stock 186 stat is best.

Sportsdude

I have 160 thermostat on my C5 with FI application to improve cooling.