Was wondering if I need to do anything like reprofgram computer if I install 160 or 175 degree thermostat? do i just replace the old thermostat?

thanks medvette99

 

I'm replacing my 160 with a 170 thurmostat because the temperature spread 168 to 225 is to much expansion and contraction for my tastes. I have a 03 C5 and I was reading 172 at freeway speeds and high 180's until you hit stop and go and then it's high 190's to 200 plus depending on delays. Yes, you should change the fan settings to more closely match your low set by the thurmostat. You can turn on your air conditioning to cool your engine as well while waiting in traffic.

I have a friend with a Z06 with a 160 thurmostat and he tells me he runs in the 180's on the freeway and 190's around town with stop and go in the 200's. He seems to run 10 degrees warmer than me so a 160 works just fine for him.

Based on what I was able to find out, OEM's like the 180 degree temperatures as a rule. Emissions may be the reason GM has us running on the hot side.

Hope this helps! :yesnod:

 

thanks for the info.

medvette99

 

How hard is it to change the thermostat? My dad doesn't like his running that hot. I've heard that a 160 is to cold. How much coolant do you lose when you swap it? Thanks for the help.

 

Yeah , what i would like to know is, if the C5 was built as a true sportscar and we know heat is a robber of HP ,WHY would they manufacture these cars to run at such high temps???? anyone ???it's got me that the aftermarket shops actively promote fitting a cooler t/stat to achieve better performance why wouldn't the factory do it it wouldn't cost any more !!

 

In my opinion it is not that difficult to accomplish. I currently have a 160o and I run around town, long trips and days at the track with no problems uncovered so far. If you believe you need something inbetween stock and 160o choose a 178o.

Either way you will need some tuning, a Hypertech, Powerloader etc or aftermarket fan product, to have your fans turn on at a lower threshhold.

If you drain the coolant like most people do and what is normally done, there should not be any loss of coolant or very little.

I did not drain the coolant. I got the new tstat ready positioning new gasket.

I put a trash can lid under car under the tstat area.

Then loosened/moved clamp for upper radiator hose and removed hose. I put something around hose to keep it propped up higher so the coolant would not run out.

I removed the two bolts holding on tstat being careful to maintain pressure against the tstat as coolant will come out if this is not done. Using my left hand (I am right handed) to hold the old tstat against the block I got hold of the new tstat with my right hand.

I then quickly removed old tstat and replaced with new tstat, reinstalled bolts, tightened them down, reinstalled hose, replaced clamp, carefully removed trash can from under car, properly disposed of any coolant there might have been and started car to look for leaks.

I did not have any leaks so I then watched the coolant level and added some additional coolant to bring level back up if it was at all down.

This is a good mod that you can do yourself.

Good luck!! :cheers:

 

I believe the reason GM has the LS1 and LS6 running as hot as it does because of trying to meet govt emissions requirements.

 

There is something I don’t understand about the need to change to the 160 deg thermostats. It seems to me, that once the thermostat is open, be it 160 or 180, what the difference when your engine is going to run at 192 all the time at highway speeds and 200-220 when in traffic. It certainly won’t hurt the car to run that hot and what makes anyone think it needs to run any cooler.
Answer please.
Flash
:confused: :confused: :confused: :confused: :confused:

 

It is thought that cooler running engines produce more HP.

 

what degree is a stoct stat????

 

I disagree with your line of thought. I had my factory Tstat removed & replaced w/172' Tstat. However, no change was noticed on my gauge until I had LS1 Edit & in the process had the fans set to come on at 190'. Well, in Central Texas it gets pretty HOT. In fact, the other day it got up to 97'. Anyway, I've been in a couple of parades with my local Corvette Club & my C5 never gets above 200'. On the highway it stays btwn 180-190' with the outside temp above 90'. I can not explain as well as others the benefits of cooler internal engine temp. Do you have an aftermarket ram air system? Well, the true benefit of those intake systems has to do with the cooler air being brought into the system & not any true ram air effect.

In conclusion, GM has to follow emissions regs & mpg ratings. Corvette Performance Enthusiast can do small to big $$$ mods to achieve an even more efficient running Vette.

 

Not exactly sure but of my memory serves me correctly it is 195o.

I can check on this to be sure and post back to you.

:cheers:

 

thanks i think your right 195.

 

The stock Tstat opens up at 195' & the fans come on at 220'. My set-up is 172' Tstat & my fans come on at 190'.

:seeya

 

Maybe I can offer a little insight on why changing the tstat can really help. Just had my Z06 dyno tested yesterday and here were the results (dynojet 248, all SAE corrected):

Coolant temp 195
Max rwhp: 353.6
Max torque: 342.3

Coolant temp 205
Max rwhp: 348.1
Max torque: 337.6

Coolant temp 220
Max rwhp: 330.6
Max torque: 325.4

As you can see, there is almost a 1 rwhp difference for every degree cooler the engine runs (at least in the 220-195 range). I asked the shop what my next mod should be and they said not to bother with an exhaust and to instead go with a 178 or lower tstat with some A/F ratio tuning as it would yield 20 more rwhp for very little cost (probably $300 total).

I'm probably going to go with a 178 tstat, which is 14 lower than the stock 192 degree unit in the 02 Z06, yet isn't so low my oil temps may be lower than desirable...

:cheers:


[Modified by Bertrand, 12:44 AM 5/2/2003]

 

Wrong. Cold air creates more HP.
Max power is produced at 200-210 degrees, Heat is important in an aluminum motor

 

:iagree: look fast and go fast. :chevy

 

Bertrand proofed it. And i had the same experience after installing the 160tstat together with the PPIII. I gained 18 HP just from the Hypertech/Stat mod.

Jochen

 

Anyone get their 160° thermostat from Zip?

The description says only LS1...will it fit my Z06?

 

I changed to a 180 thermostat and my car runs the same as before becasue I didn't do anything to have the fans come on earlier. When I talked to Ed Wright once, he said that this particular type of engine produces the best horsepower around 190-200 degrees. I know that colder (denser air) produces more horsepower, but I'm not sure if a colder engine would. Anyway, that is just what he told me when I was asking about some tuning.

The only thing I notice is that except in traffic, it doesn't seem to matter what the temperature is, my car still runs at 194 degrees...so to me that implies that the thermostat is pretty much always open. because no matter what, it won't go below 194 in normal drivinig, even with the lower thermostat.

To me, it seems that colder air will make more horsepower but not a colder engine because how can a colder engine affect the air that is travelling through it so quickly? Oh well, this is for the engineers to figure out.