thermostat

**95Z28terror** · 09-13-2006, 03:43 PM

i just bought a 160 degree powerstat thermostat for my 95 Z28. do i have to drain the coolant to get the thermostat in? anyone have numbers on the hp gain? anything would help

**BlackLT1Z28** · 09-13-2006, 05:23 PM

You don't HAVE to drain the coolant for a thermostat change. Just be aware that when you do remove the thermo housing and the thermo itself, you will lose some coolant. Be sure to let your car sit overnight before you do it though so there is not pressure in the system, or you will lose a lot. And make sure to cover your opti with some towels so you don't get coolant on it, or you will have to replace the opti and that sucks.
Haven't seen any real numbers for it, but a cooler running engine is always a plus.

**sunsetorangess** · 09-14-2006, 06:31 PM

Like said above its safer when done with the car cool. Make sure you pick up some rtv and as far as gains go you probly wont see any, Just bc you put the thermostat in there the comp doesnt know its there, so it will flow the coolant but the fans will still kick on at normal temps.
Wont hurt thou
J

**koolaid_kid** · 09-15-2006, 07:41 PM

To really see the gains, you have to program the computer to turn the fans on earlier. If you don't have a programmer, I think there are stand-alone switches that can do it for you. But alone, it is a waste of time.
I have one, and I programmed it with my HPP. It worked great. But when I had it tuned for the turbo (oops, did I say turbo?) I forgot to tell the tuner that it was a 160. So he set it for the factory thermostat and it started running hotter again.
And there is a (bolt?) that you open to let out the air that you let in when you opened up the system. Been a while for me, but the instructions should tell you about it.

**BlackLT1Z28** · 09-19-2006, 03:14 PM

Its not a bolt...its the bleeder screw. And there's 2 of them. Its used to bleed air out of the coolant system. You have to bleed the radiator every time you drain/refill it. It could cause your engine to run too hot too soon. The bleeder screws can also be used to indicate if there is enough coolant in the system.

**HeadDown** · 10-12-2006, 07:00 AM

On this same line...How cool is too cool? In the aircraft world we find that much under 200F cylinder head temp is not good for power or longevity. Does anyone have good data for the ideal coolant or CHT temps on the lt1?

**RAT454** · 10-12-2006, 07:23 AM

Check out Scotts article at
http://www.theherd.com/articles/lt1_cool.html

I found that I picked up a little power with a swap to a cooler stat (180) in my 95 Caprice, but my milage went down also...haven't seen numbers on gains, mostly just seat of the pants comments...