I know in theory lowering you engine temp increases hp alittle, so I was lookin into switching to a low temp thermo but i read somewhere that the low opperating temp can cause problems with the PROM, unless you have a chip designed for the low temp ..........anyone else heard of this?

 

yeah its all over this board... try searching through the boards, people have documented the pros and cons..

i would not run anything lower than 170 in my car..
i am thinking about a 180 to keep me alittle bit more cool in traffic..

really low engine temps can make the cars fual mileage go down hill, the only way you should get a 160 therm is to get a custom chip made and make everything controlled by the computer to corresond the the new lower temps or things will most likely not be running to their potential..

 

I first put a 160* stat in my 92 z28 to try to get temps down and I only noticed lower temps while crusing the highway at 80mph. In traffic no matter what the outside temp, it would still climb to 220.

 

I have not heard of engines making more power when cool. They could make much more power if they could run really hot, because the efficiency of any combustion based engine is related to the difference between the high and low temperatures that the engine operates between.
You will get more power if the engine sucks in cold air from outside the engine bay, because there is a greater temperature difference than when hot air from in the engine bay is used.
The only reason for restricting engine temperature is the materials the engine is made from.
If you run the engine too cold, nothing will be working at the right temperature, from the control system to the ability of the oil to work properly.

 

By running the engine at a cooler temperature the computer will give it more fuel to try to get it to "warm up". That is why I think some people think running cooler gives you power. Instead they give themselves a broken wallet by wasting gas. Of course I just retuned my eprom to take advantage of the cooler temps I want to run the engine.

 

It only gives it more fuel trying to warm up the engine if you don't change the PROM settings. The car will also run warmer with a 160* thermo if you don't change the PROM because the fan is computer controlled and won't go on until 195* hence no cooling. You have to change when the car goes into closed loop and customize the settings of the fuel for the car can take advantage of the cooler temps. The high temperatures that are cars were made to run in were because of emissions issues. The warmer the engine the more throughly it burns the particles improving its emissions. The best way to shop for thermostats is look at the environment the car will be running in. Is it cold a lot where you live, that would be a factor. I live in a warm climate so a 160* thermo works perfect for me. My car is noticably better running colder than running warmer. If you go with a 160* I would strongly recommend changing the PROM or you will not recieve the full benefits of a 160* thermostat.