ThraxXx

Hey All,

This is a seriously newb question however I always wondered. When a thermostat is 180 degree or 160 degree...exactly what does that mean. Is that the temperature that the stat opens up to allow coolant to go through?

dimented24x7

iTrader: (2)

Yes, thats the temp that the t-stat will allow coolant to flow. below that it begins to close down and restrict coolant flow.

ThraxXx

would it be a good idea to put in a 160 degree thermostat in a modded 305 TBI? or should I just leave the stock one....whatever the stock one is set to.

ElementsofSpeed

if you use a lower degree thermostat than stock, which i believe is around 195...then you have to get a fan switch too. Hypertech makes one. Your fans normally turn on at around 230 and off at about 220. The switch turns the fans on at 200 and off at 185, so when you use a 180 degree thermostat, you can use your fans.The switch is like 40 bucks.

ThraxXx

Reason why I am asking all this is because I noticed on TBI chips that they stated that their chips require 89-91 octane gas unless you install a 160 degree thermostat then you can run 87 octane gas. So I am thinking that this would be the best way to go as gas prices don't seem to come down as much as they go up and I really hate seeing the price outrun the liters.

dimented24x7

iTrader: (2)

Sticking the stock chip back in and continuing to use the 195 would be your best bet to use cheaper 87 octane. You could go lower on the temp side, but the stock cooling system is designed to reject the right ammount of heat around the temp that the stock t-stat keeps the motor.

dimented24x7

iTrader: (2)

Oh, BTW, all those 'chips' really do is add uneeded timing and fuel in the upper rpm/load range and lower the closed loop enable temp. Kinda useless IMO.

ElementsofSpeed

thats why you should just get the switch IMO. the switch just activates your fans earlier and doesnt mess with anything the computer tells the car. If you go 160 degrees...it might be to cold for in the winter...if you live up north or have cold winters, i would use the stock thermostat or the 180.

dimented24x7

iTrader: (2)

In the tbi cars, they use a fan switch, so you can easily change when the fans come on.

ElementsofSpeed

exactly...without the switch, you cant run the lower degree thermostat...you will destroy your motor.

dimented24x7

iTrader: (2)

How would using the stock f-switch kill the motor? Granted it wont come on untill around 220-230 or so, making the lower t-stat useless.

I use teh ecm to control the fans. I have them come on at around 220 and turn off at 200 with the stock t-stat because I got tired of having the low temp f-switch with the 180 t-stat. Ran the fan constantly in the summer untill it finally wore out and burst into flames.

kevinc

Please do clarify on that statement.

(Just for funnies.)