slp--firehawk

I thought a 10ish fold compression ratio at higher temperatures operates more efficiantly than the same thing at a lower temp. Are the thermostats just for cooling the metal of the engine to pack more air in the cylinders or to richen the tune up or am I mistaken all together or what?

MrElectric03

iTrader: (71)

Not really something I can answer with alot of confidence, I do know that my car always ran hot and I never thought to check it because I never had a problem. When it was on the dyno it was running in the 230* range and making 425-430rwhp. We shut the car off and let it sit for about 20 minutes to cool down and tried again. At 205-210* it made 443rwhp.So it shows a cooler running engine will make more power.

Now ive cooled it down by using a 160* thermostat and it runs a constant 176* and have added a 9" rear but havent been able to get it on teh dyno again yet.

old motorhead

iTrader: (10)

A hotter engine runs a little more effeciently. But a cooler engine allows more aggressive timing hence better power numbers. All things being equal, a hotter engine will do better MPG wise. A cooler engine has the capability to make more power. If you want the most power out of your motor, it can be tuned more aggressively if it's cooler. It won't get the economy numbers though.

SweetS10V8

iTrader: (4)

The thing no one mentions is that once your thermostat is open, its open. It doesn't cool anything. It just lets your coolant flow through the radiator sooner.

So if you cooling system can not cool already, say after your engine reaches 200*, both the 160* and the 195* t-stat will both be open and its up to your cooling system to cool.

I wouldn't ever think of a t-stat as any kind of "mod" or "performance piece", its just a waist of bandwidth in most peoples sigs.

Chrome355z

iTrader: (1)

That's true, but lets say that you are doing some casual driving around town. Your engine will be operating at (for simplicity sake) 160 vs 195. Then you line it up at a stop light and get on it. Your engine will be cooler at that point with the lower T-stat hence more power. Same if sitting in the staging lanes at the track.

Now lets say your running an autox event and constantly on it, then no. There is not really going to be any benefit.

I like my engine to run cooler so I get a little better transmission cooling from the factory radiator for my transmission before it goes into the secondary cooler...

But for most people, they might as well stick with stock as they will get better MPG.

toothdoc

iTrader: (7)

So you are saying that the stock thermostat will make better MPG? How much worse MPGwould a 160 thermostat make?

Chrome355z

iTrader: (1)

Have no clue, you'd probably have to do a back to back comparison. They also run the engines hotter for better emmisions as well.

slp--firehawk

Yea thats what I pretty much knew of, better efficiency and likewise lower emissions. So say your cooling system has no problem cooling to whatever, you put a 160 degree thermostat in one day and drive away expecting your engine to be faster. Does your computer program actually not only pick up on that but advance your timing for you automatically? It seems our EEPROMS would be a little elementary to do that all itself, wouldn't you have to flash a program for it to understand what to do with the new thermostat

old motorhead

iTrader: (10)

A cooler running engine allows more timing. Doesn't do it without tuning.

I don't have any before and after experience with LS engines, but on an LT1 vette, after a tune and a cooler stat, the power went up substantially, but fuel eco went down at least 1+ MPG. C4 vettes have just enough cooling capacity to keep things from boiling on a hot summer day. When the car was running hotter, even with the cooler stat, it always got a little better fuel eco.