plumberh2o

I found two thoughts on this add on. Is it a good thing to install a 170 thermostat in a C5 2004 Vet? I have Ecklers saying cooler is better saves ware on engine parts will last longer less heat less fuel. Then A motor builder told me that the cars system/ Computer system is set up for the car to run at 220 and if it is running cooler it will through codes and mess it up. I am confused about what is the right thing to do. does cool go fast or not???? or

Evil-Twin

You have been on this forum for a long time. There are hundreds and hundreds of threads with opinions that vary from go as cold as possible to leaving it stock. I know the answer to the question but posting it only reopens a very old can of worms. The short answer to your question is, leave it alone . Leave the stock stat in the car. as far as someone telling you at 220F your car with throw codes, I would suggest never asking that person anything about a C5 corvette.
Everything is a trade off.. go cold and get a few more ponies, but at the cost of engine longevity. Leave the stock stat in there and the car will perform as designed. Just to prove a point , go out and look at your temp gage.. Note where the red line starts, anything below that is within design specification, that red line is a far cry north of 220F.
Tuners will tell you that running cold makes will give them the ability to add some advance and make the car go faster, its their job to give you more HP, that's what you pay them to do, what they don't tell you is that running cold on a heat spec motor, with tight clearances cause oil shear, which will break down the lubricity of the oil, and its additive package.
Ask a Corvette design engineer which stat to run and I will tell you to keep the stock stat in there. I will not respond further in this thread, the worms are out of the can. IM always available in private message.

65GGvert

Nay for me. A lower thermostat alone only makes your car run cooler in the winter time when you don't need that.

HardcoreABN

Also, the radiator will do more to effect engine operating temperature than the thermostat will. you could put no thermostat in there and it will still run the same temp range just take a lot longer to get there.

NukeC5

This is asked a lot on here. I always say to leave it stock. Im making 430whp on my heads and cam build. No less than others that tinker with the thermo. And Mines still emissions compliant. Sounds like a win win to me.

Smoken1

I would have to agree with the above posts as your fans are not going to come on till the 220 range unless you have it re-programed to

plumberh2o

Looks like I am sending that thermostat back and not messing with the temp unlike I did with my 86vet . Thanks for the info, I am still looking for one more second off my 1/4 mile time. I know this is going to cost me some$$. I have to find the best way to do it. Thanks to all.

Evil-Twin

The first second off your Et over a stock engine is cheap and easy, then the next few tenths are very expensive. The first second can cost you a grand, the next 10/ tenths can cost you a thousand dollars each tenth.

plumberh2o

I am trying to run 11.5 1/4 . With my Drag radials very-ram intake and a predator tune. I am getting 12.8 on a cool morning. I want 11.5 or 11.6 What do you think I need to do to get in to the 11's.

Smoken1

Full exhaust upgrade will help...but thats a couple grand

vettenuts

If you have an auto, gears and converter will likely do it. You can find 3.42 take outs in the for sale section with the later units being better and the Z06 being the best for take outs. Otherwise, ECS can do it to your existing hardware.

As for the thermorstat, you can adjust it yourself but have to test it in a pan to get it close so paying for an aftermarket one is expensive in comparison. As for fan temps, you can use a Vinci controller (if they are still available) that allows self adjustment or get an aftermarket programmer to adjust the fans. On my prior setup I had the stock thermostat and set the fans to come on at 208,, which with the Vinci, shuts them off at 201. Of course once the car starts moving the temps come down to the low 190's.

Quite honestly, you can play with the engine temp until the cows come home but it certainly won't pick up a full second on the track.

Darrell98

What is the stock thermostat temperature on a 1998 ? So I get the correct one.

cv67

Dont worry about longevity.
Last car I sold now has 180k on it and has run 160 stats forever.

vettenuts

It opens around 187 from I have seen on the display.

plumberh2o

What year was it???

Murder_C5

Your goal of 11s' is SIMPLE, JUST AD BOOST.
Or the CHEAPEST ET dropper -Boost n' a Bottle- (No2) if you just want to drop ETs at the track.
Leave the stat. alone. If you want temp control get a programmer or fan controller. Assuming you already have a Predator tuner, you can adjust the fans now.

strand rider

Well, you already have the correct advice, long before I got here.

To put it into a handy travel size, with this buying decision, you need to know what problem this is the solution to.

To put it more simply, every problem has a solution, this thermo setting is a solution to a problem, but you have not identified the problem this solution will fix. So you ask the question, seeing this thermo as a good addition, yet are unsure of the application, if I see this correctly.

Which leads us back to the answers that had reason, mine only had logic.

When I see people with needs to run the machine outside the design specifications, I always trust it is for good reason. As was pointed out above, every GM design is a compromise, and I have to go with the trained engineer, the guy who drives to work everyday and does this for a living, over the guy that thinks he knows better , hasn't blown anything up yet , so posts here about a better idea . I'm thinking, in particular of a post I read by a guy who is using conventional motor oil in his c5. Says the syn. oil requirements are unnecessary , everything is fine. Kind of exaggerating to make the point, by digging that out, but sometimes that is a quick way to illustrate things.

A lot of guys don't get that modern engines are designed all the way down to the smallest consideration, like the heat carrying capacities of the oil. Some have the ability to modify the engines enough to require a rework of supporting systems. Other guys just wing it , I guess because it is easy and makes their car now more personal or unique?, nor quite sure why. At least that is how I read the stuff posted around.

enoniam

My 2003 Chevy Avalanche with it's LS1-based 5.3 engine running a 160 stat, 0.551 lift cam, aftermarket valve springs and shifting at 6300 lost a lifter/cam lobe at 262K miles. Also had a Vortech supercharger on it the last 50K miles or so. Always ran synthetic oil (usually Redline) and changed per the oil life monitor, until going to 6K mile intervals after installing the supercharger.

n8dogg

Some heated debates on this topic. My recommendation is a 180*. These engines were designed to be durable and last 200k miles. A big contributor to this is the engine oil and engine cooling systems and the temperatures they are designed to run at. If you stray too far from the designed temperatures you can do more harm than good.

enoniam

I totally get where you are coming from n8dogg - I'm usually on the conservative side when doing my mods, particularly computer tuning. I've wondered more than once if a 170 stat would be better for my truck. It tends to run around 180 during the winter. Fans are of course quite active in the summer - I'm currently turning them on at 193.

Probably more so than the engine's life I'm concerned on the C5 that I bought a couple of months ago its automatic transmission's life. 200 degrees in the tranny is more than I'd like to see, but I see it pretty often. I need to check for debris around the radiator but if I can lower the tranny's temps buy running a cooler thermostat together with turning the fans on sooner that for me is an easier solution that installing a tranny cooler. I know an aux tranny cooler is the better solution but I'm inclined to try the easier solution first to see how it works and then go to the more involved if I think more cooling is needed. I installed an aux cooler in my truck about a year ago before crusing the Blue Ridge Parkway with it and it's 3200 stall converter.

Before doing anything though I need to let it idle up to temp in the garage and with the hand checking the radiator hose method try to figure out what it has in it now. This thing sounds for sure cammed, has long tube headers, Weiand/Lingenfelter intake manifold and what sounds like possibly a Corsa Indy exhaust among other mods. When I bought it computer was custom tuned (not very well) including turning on the fans at 183.