: 160 degree thermostat



svassh
11-27-06, 07:56 PM
If you have it let me know your thoughts. Down in the south my car gets pretty warm. I gotta believe it would benefit from a little cooling.

50 4Ever
11-27-06, 08:49 PM
I have a 160 degree thermostat in my Corvette and I have a Predator and have lowered the temperatures that the fans come on. I don't think that you will benefit unless you have a tune that reprogramed the fan temps or a handheld tuner like a Predator.

:thumbsup:

DILLIGAF
11-27-06, 08:50 PM
You will have to get a tune when you change the thermo.LS6=the cooler the better!

heavymetals
11-27-06, 09:09 PM
Did it to mine (what haven't I done) and it seems to help.

C66 Racing
11-27-06, 10:19 PM
A 160 thermostat really won't lower normal coolant temps. I don't know the specific setpoints for the CTS-V, so the below discussion uses Corvette C5 numbers, but you should be able to get my point.

When the car starts and the coolant is cold, the thermostat will remain closed so the fluid doesn't circulate to the radiator so it heats up faster. The thermostat will open at about 194 or so allowing fluid to flow to the radiator. Once your car is warmed up, the thermostat thus sets the low temp because if really cold air flows through the radiator cooling the coolant below 194, the thermostat will go towards shut, reducing flow to the radiator and the coolant will remain at about 194.

On the high end, the temp is controlled by the fans. Though the fan setpoints appear to have varied slightly over the years, they are about: low speed on at 226, off at 219; hi speed on at 235, off at 226. So in stop a go traffic, it is not abnormal to see temps in these ranges.

Other things to consider are that when the AC condensor is on, the fans will run, thus if it is hot enough out for the AC to run and the fans are on, but the load on the engine is low or airflow through the radiator is high, the temp will go down to the 194 range where the thermostat will go closed again.

The car can reach an equilibrium in between 194 (thermostat closes) and 219 (fans come on) dependent on engine load and airflow/airtemp flowing through radiator, thus you see many guys say their car runs near 200-210.

Thus installing a 160 thermostat will only lower your lower coolant setpoint, but it won't address the upper end which is normally controlled by the fan setpoint.

Another thing to consider is that the oil should normally operate around 212F or so. If the oil is kept well below 200F due to low coolant temps, moisture in the oil won't boil off as fast and that could lead to condensation and potential rust in the motor.

svassh
11-27-06, 10:29 PM
C66 - Thx a very educational response. So without reducing the point at which the fans come on the 160 degree thermo won't buy me much cooling wise.

I notice a dramatic decrease power and response wise between when I first get the car moving and 30 minutes of stop and go traffic. So was hoping to keep the engine cooler and more responsive.

I was not aware of the impact to the oil temperature though thats a little scary.

DILLIGAF
11-27-06, 10:56 PM
C66 - Thx a very educational response. So without reducing the point at which the fans come on the 160 degree thermo won't buy me much cooling wise.

I notice a dramatic decrease power and response wise between when I first get the car moving and 30 minutes of stop and go traffic. So was hoping to keep the engine cooler and more responsive.

I was not aware of the impact to the oil temperature though thats a little scary.
Thats alot to digest,you will need a new tune either way if you do the thermo.The cooling fan stratagys is one of the reasons why you will need a tune.My operating temps went down 20 degrees, period.Shoot stealth a e-mail he'll set you straight on all the benefits of a tune with the cooler thermo.Condensation in oil,are you kidding?

nikon
11-28-06, 10:05 AM
well, ive got a 160 in...coolant temps run at 176-7 while cruising...never tuned it....as for oil temps, it takes a little while but my oil is usually always abouve 200*...so I guess no worries for me there...still never heard of condensation in the oil.

50 4Ever
11-28-06, 01:38 PM
well, ive got a 160 in...coolant temps run at 176-7 while cruising...never tuned it....as for oil temps, it takes a little while but my oil is usually always abouve 200*...so I guess no worries for me there...still never heard of condensation in the oil.

As far as I know these engines were designed to run best at a water temp of 192. When crusing mine does and the oil temp is around 212, there has been a lot of discussion about this on the Corvette Forum for many years. Bottom line, personal preference.

:thumbsup:

nikon
11-28-06, 01:55 PM
As far as I know these engines were designed to run best at a water temp of 192. When crusing mine does and the oil temp is around 212, there has been a lot of discussion about this on the Corvette Forum for many years. Bottom line, personal preference.

:thumbsup:

ditto...theres alot of mixed responses..Ive read most of em...I would just rather have a cooler engine...to each his own.

C66 Racing
11-28-06, 10:08 PM
well, ive got a 160 in...coolant temps run at 176-7 while cruising...never tuned it....

If air temps are reasonable and engine loading light, with sufficient airflow through the radiator the coolant temp will lower until either equilibrium is reached or the t-stat setpoint is reached. In your weather and engine loading while cruising you are probably reaching equilibrium at 176ish. If you stopped though, your temp would climb to the fan setpoints.

Seems like most of the guys I've read on the Vette forums getting 160 degree t-stats do so to improve performance at the drag strip. The car will make more HP while cooler. So they also modify the fan setpoints so the temp stays low. For my track Z06, I modified the fan setpoints, but left the stock t-stat... and added a bigger racing radiator with more cooling capacity than I need. So my temp stays right about at 194, the setpoint of the stock t-stat.


... as for oil temps, it takes a little while but my oil is usually always abouve 200*...so I guess no worries for me there...still never heard of condensation in the oil.

There is a little bit of a discussion about rust protection in this AMSOIL motorcycle oil link to my dealer website:
AMSOIL SAE 10w40 Synthetic Motorcycle Oil (http://www.c66racing-synthetics.com/Product%20Bulletins/MCFPM.htm)
:cheers:

Albertan
11-28-06, 11:19 PM
Nikon
Ah, you've never heard of condensation in oil because you live in FLORIDA! Here in Alberta we just set a record last night -29C with a wind. Yep, we get condensation alright. If we drive lots of short trips in cold weather the oil will turn milky, not good.
Also, usually until an engine is up to operating temp, the computer will be running in open loop mode and not produce proper power.
Bruce

JKG
11-29-06, 02:58 PM
Well, I installed a 160 thermostat in my V recently. I can tell you with certainty that the car runs around 180s while cruising, and then rises up from there. So, if you do not change fan settings, you will still get lower temps while cruising. I set my fans lower, so now it never goes above 200. I have never had problems with condensation and rust in these situations. It is more of a problem when you run a car a short time once in a while, when the oil temp does not reach normal operating temps.
By the way, on my inaccurate stock oil temp gauge, the oil temp runs higher while cruising.

Tags63
11-30-06, 08:10 PM
Hey All!!

I have mine in. It's a no brainer since heat is the killer of motors especially when we start modifying them. The cooler the better.........

Paul:thumbsup: :thumbsup: :thumbsup:

ace996
12-01-06, 12:36 AM
C66 makes excellent points and has a little experience with the LS6...:thumbsup:

The 160tstat doesn't really run as low as 160degrees...usually higher, some in 170s some low 180s. In very hot temps, it's the fans that keep the motor cooler. If the fans are reprogrammed, it'll help a great deal in stop'n'go traffic.

The real problem comes when the system can't shed enough heat...like on a roadcourse. There are some good things to do for both street and track alike...
1. Drain some antifreeze and add distilled water. Antifreeze is a poor "coolant" and doesn't shed heat like water. If you're in seasonal areas, like me in NY, then I change every Spring/Fall. In the winter, I run 50%/50% anti/water. When it warms, I go 20%/80% anti/water. Before trackdays, I only run water and WaterWetter, with a bottle of water-pump lubricant.

2. Redline WaterWetter. It helps pull heat from the engine by making the water better able to absorb it. Their website explains it....bubbles...ect. When I ran a Ducati 996 on tracks, it was a lifesaver. Your normal operating temperature may run a little higher, as it is doing a better job of pulling heat from the block...but your highest temps will be lower.

3. Wrap your headers/exhaust manifold. Yes, this is a debateable practice for part longevity, but lowers underhood temps and that's always a good thing.

Really, though...a change of programming for the fan temps would probably be all you'll need. An easy thing to do with EFILive.....:thepan:

There is such thing as too cool for a motor. The LSx motors like some heat. If you run constantly below 180degs: your oil will never burn off moisture, your mileage will suffer, you'll run rich..ect.

Be good,
Tom

C66 Racing
12-01-06, 11:03 PM
All good points Tom, but you've definitely brought the thread up to the graduate level discussion.

Similar to you, I run a 25% antifreeze, 75% DI water in my Z06, plus a bottle of Redline Water Wetter... well, that and I have modified my fan setpoints and installed a Ron Davis aluminum racing radiator and an Earl's oil cooler. :D

I haven't really noticed much benefit from the Water Wetter in the LS6, but I did notice a big difference in my last track car, a 94 RX-7 so I've kept using it.

I'd also wrap my exhaust as you mentioned, but it's not specifically allowed my the rules in my class, thus it puts me at risk for a protest that would hard to beat. On the Vette, what I really want to do is wrap the exhaust in the vicinity of the tranny and the diff to help reduce heat input to those already hot running components.