I have a 178° thermostat and the coolant temperature is steady at 181° to 185° most of the time. Should I change to a 160° thermostat? If I do, can I just get the thermostat without the housing this time?

 

Not sure about the housing question, but I have the 160° and my coolant temperature stays around 175° while i'm driving on hot florida summer days.
If I sit in traffic all day, I have seen it go as high as 190° (thats probably due to me not having the fans kick in till around 190°)
I like the 160°
It's what I ran in my 87 for 12 years too. :cool:
It also seems to me that if My motor will run happily at 175° with an open 160° thermostat, then yours is never getting the chance to run at that low of a temp due to your thermostat not fully flowing until around 178° ... Make sense?
Cooler = longevity + more power

 

This is also my next mod !!!
Go to thurderracing.com, they sell things real cheap compare to other dealers.
:cheers:

 

Personally, I would monitor the oil temp rather then the coolant temp. Optimum oil temp is 200-210 degrees.

 

food for thought. I have proved time and again that the LS1 is more powerful at a temp of ~195F vs something lower like 170F. At the drag strip i have pulled a faster speed and time at ~195. cooler or warmer than that has been less than optimum. I spend a lot of time at the drag strip. I cool the motor as low as 170, then once i burn out and stage, i am around 195 or so.

 

I would agree that you have proved to yourself that YOUR LS1 is better at 195, but it's pretty bold to state that THE LS1 runs better there. Even stock as they leave the factory we see big differences in how they run and what makes them run better, and when the mods begin...all bets are off.

Mine runs better at 180, I proved it like you at the dragstrip, by gaining 2 mph and 2 tenths quicker.

With the 160 thermostat mine runs at 175-180 sitting still, works great :cheers:

 

If your running at that temp why would you want to lower it anymore??? I'm more than happy with my 178....

Tony

 

If I remember correctly, Thermostat 101 says the fans help control the max. temp. while the T'Stat controls the minimum.

 

Hex29A:

The opening temp rating of your thermostat, be it 160 or 178, will NOT be the ultimate factor in how hot (or cool) your car will run. It is ONLY the temp at which the thermostat will open and allow coolant circulation throught the radiator (heat expraction system).

Unless you have an extremely large radiator and air circulation system in your car, which most of you don't, then the operating coolant temp will be dictated by the amount of heat being put into the coolant by your engine (more HP output the more heat is put into the coolant) - - and - - the efficiency of your heat extraction system, which is the size of your radiator, the air temperature and air flow through your radiator.

If you want lower running temperatures a lower opening thermostat will not give it to you, unless your heat extraction system can give it to you. If you really want to run operating temps of 160, then get the 160 thermostat and also add the huge racing radiator and large fans which come on at 155 and you will be there. As others have stated, I don't think that 160 is the optimum operating temperature for your engine, but if that is what you want, go for it.

If you think that 178 will susfice your coolant temp needs, then set your fans to come on at 175, and install a BE-Cool oversized radiator. I'll guarantee that your coolant temps won't go over 180, and that is a pretty efficient operating temp for your Vette.

When I come off the track at Watkins Glen, or VIR in the summer with air temps of about 90 degrees, my coolant temperatures are running about 185, ant this is with a 178 degree thermostat and NO fans running. When I slow down comming into the pits, the temperature goes up because the air flow through the radiator is deminished. My larger Be-Cool radiator also lower the operating oil temperature about 30 degrees. Hope all of this helps you make a decission. :cool:

 

Is this optimum oil temp documented somewhere? I've always thought that Oil Temp was more critical, and that is what I keep on the DIC most often. Is there an oil temp that one considers to be the "warmed up" point?

Thanks!


[Modified by C5 StockSwap, 3:59 PM 5/22/2002]

 

Good observation C5 StockSwap:

One of the viscosity measuring points for classifying motor oils is at 100 Deg C, or 212 Deg F. I am unaware of any one temperature that an oil is considered to be "warmed up", but to me I wouldn't be doing any serious high rpm driving untill the oil was at least up to 200 Deg F. I usually see oil tempes between 230 and 260 on the race track, and that seems to be "normal" for those conditions, although before I add the Be-Cool radiator I was seeing oil temps in the 270 to 290 range. But the Synthetic oil is good up to about 350 before you start making varnish and sludge. :cool:

 

This is true but we cannot do anything to lower the oil temp beside the oil cooler.
I got oil cooler installed in one of my car but not my C5 since the C5 does not have enough space to add the oil cooler coupling and then the oil filter. I have seen someone had to move the oil filter somewhere else ... :cheers:

 

Jim 47 is right. The only thing a lower thermostat will do is run your car cooler in cold weather. You are just right, where you are. You could, if you want, lower the fan temps a little. LS1's make the best power around "195 deg." It's hard for us to know, since as engine temps go up air intake temps go up and it seems that hot engine less power. The opposite is true. Hot engine cool air = more power.

 

Thanks to everyone for their comments.

I posted my coolant temperature so that it can be easily related to the thermostat rating.

As most of you stated, just putting a lower thermostat will not help if the fans are not reprogrammed to come on at a lower temperature and if my radiator is at its maximum heat exchange capacity.

Although I had the thermostat installed last year, I just finished re-programming/tuning the car computer. I didn’t have the chance to experience the effect of the hot summer at the track with the new setup. As I stated at the opening post, the coolant temperature is at 180° to 185° most of the time now with my oil temperature about 10° higher than the coolant temperature. On the average, that translates to 191° to 195°.

I am not aware of what the optimum oil temperature is for drag racing for the Corvette. I was under the impression that the closer to 160° the better (for oil temperature).

From experience, my first run at the track is almost always the fastest. After that, is all down hill until some car “pukes” on the track and we sit there for an hour until they clean it. At that time, if the weather is cool and the car had enough time to cool below 160° (oil temp) I have a chance for a new day record (By the time we stage and this and that the oil temp is up to 165° to 175°).

Once again, thank you for your comments.