2003silvercorvette

i was looking at LAPD and found the hypertech 160 or 180 degree thermostat, and i was wondering why there is 2 different ones and which you guys recommend to run. thanks

c5chris

I have a 180* and I see my Coolant temp to stay at 189* even when idling. Of course to see an effect on your coolant temps, you need to adjust your fan controllers. By itself, a lower temp t-stat will not do the work alone.

Im tempted to go 160* since we never have realy cold weather here in California but 187-189* range on my C5 is fine as it is.

JH

There was quite a discussion on this last week, as I recall. Look back. Lots of great information.

phils C5 vette

I couldnt make up my mind on either thermostat so I went with the 170 degree which I thought I bought from corvette central. A year later, it was getting stuck open at about 140-150 degrees

when I had the cam installed 2 months ago ECS put in the 160 thermostat. I cruise at just under 180 degrees, and idle for a while it may go as high at 190. The fans are set to come on at the same time, but im not sure at what temperture ECS set it at

I idled for 45 minute last week to heat up my cats for inspection, and the car didnt get above 190.

ben dover

Again, the hotter an engine runs (short of damage) the more efficient and powerful it will be. The only thing that needs to be cool is the intake air.

6Speeder

That's correct as long as you don't get any spark knock or detonation. If (when) these these occur, you must cool it off to make power or risk damage. The trick is finding that point of highest output. GM runs these engines hot for emission control, and backs the power down by pulling timing when spark knock intrudes. If you keep the cylinder heads a little cooler (175 to 190) you reduce hot spots, can increase the timing, can run higher compression, and will make more power. A 160 thermostat (with earlier fan turn on) will keep the engine in that sweet spot (mine stays at/about 178).

I run 31 degrees of timing, on 91 octane gas, with 11.4:1 compression, with ZERO knock retard. It makes great power for a baby cam, passes smog, and gets better than stock gas mileage. I could not tune it for these results without running it cooler than factory stock.

Get the 160

2000BSME

That is NOT correct. Heat is the enemy of power. People try and get the 160 &180 degree tstats to make MORE power. An engine running at 180 vs 220 will make MORE power. Higher temps allow for lower emissions, not more power.

byte_me

I put a 180 T-Stat in my 97 (that had the GM stock temp whatever that was) I was averaging the high 220's even as hot as 238 Degree F!!! Way tooo hot for my liking and this was on the highway doing 85MPH...since the 180 I average 198ish normal driving and in stop and go traffic- it can get as hot as 218 or so...but it goes right back down to the lower number as soon as I start rolling.

I am in South Florida- it gets HOT here and stays HOT for a LONG time! so I am happy with my 20 to 30 degree drop in temp!

Cheers~

ben dover

hey bsme, surely you took a couple of courses in thermo? You have to know better.

Special K

A GM engineer told me that 190 is perfect. I run around 180 using a 160 thermostat.

Thermo, whatever that is (thermodynamics?) really has nothing to do with it. It's what operating temp the engine was designed for.

Bob

lvvette777

edited

lvvette777

This is spot on!!!!

ben dover

This one of the guys you talked to?
General Motors Vice Chairman Bob Lutz says that engineers coming out of U.S. schools lack the hands-on experience they used to have—which would give them "bone deep" understanding of the products they develop.
http://www.automotivedesignline.com/news/160701876

Special K

Evil-Twin, a retired GM engineer is where I got my info. He is by no means a 'junior engineer'.

I'm not going to get into a pizzing contest. Run your engine at 240 if you wish. You're the one that mentioned thermo.

Engineers coming out of school know very little. That's why there are senior engineers in charge to direct, teach and check on the young guys. Some day they will be the senior engineer with the knowledge required to do the job. They are not the guys designing these engines.

Bob

Evil-Twin

Again and again ben dover, you have no clue about this LS1/6 motor and its development... IT is a tight clearanced aluminum alloy engine. it has a sweet spot. Every tuner knows this... keeping it in the sweet spot is what everyone strived for... the sweet spot is 190/200 coolant and 200/210 oil temp.

I was fully involved in the prototype design and subsequent launch and post launch debugging of this car, I have 35 years of automotive engineering under my belt I am an SAE Sr Engineer. This motor is almost bullet proof with the right configuration, that is, the right oil, and the motor running at the right temperatures, both oil and coolant. This allows proper lubrication , suspension of contaminants in the oil, and reduction of thermal breakdown... The sweet spot was established buy thousands of hours of run time while developing this LS1 design... simultaneous test were done to develop the algorithms for the oil life monitor, under all types of loads and driving conditions.. unfortunately WE build cars that run in Minnesota in the winter @ -30F, and the same car has to run in the Arizona desert @ +130F. The hp vs. cu. in of the LS1/6 was developed through tight clearances and a lubrication system that needs the right combination. Running an LS1/6 at 160 F will cause premature carbon build up...increase compression ratio, cause automatic Knock retard sensors to retard the timing, thus causing a loss in performance.. WE ( GM engineering ) have seen this scenario so many time we have developed the famous GM De carbonization process... these cars run anywhere from 190F to 235 F. and that is normal in the general design.. the PCM helps to compensate for this variance with appropriate fan settings.. but the car runs best at one temperature..both coolant and oil.. but it will function and various temperatures.. the sweet spot is insider information..keeping it in that sweet spot is what a well tuned engine wants to see.. and where optimal performance is gained...without loss of internal integrity
This is similar to the tire pressure sticker 30 pounds cold on the door... it is just a generic tire pressure sticker setting.. so customers wont use the max pressure settings on the tires,..,, but that 30 psi sticker is just a general statement.. the tires perform best at 30 psi.. but if you set them cold at 30 psi and get out on a Hot black top on a summer 90+ day road where temps can reach 160F, those tires will increase to 36 psi... that is not where they should run... I never allow my tires to get over 30/31 psi "Hot" that's where they perform,, they do not perform cold...so why set the temperature there. Tire pressure is so critical... Nascar pit crews monitor track temperatures all day long and adjust tire pressure accordingly. Two psi can give you better mileage and more tire life... these are critical in Nascar. A few extra laps on the tires and better fuel economy are all part of a well tuned Nascar. Not as critical to a daily driver, but the concept is the same... I consistently get 33 mpg on the highway with my car.. and I can get 45,000 miles out of a set of tires.. because I know what I am doing.. my car is tuned for me and where I live and how I drive... I have been trying to teach this concept to people here... many have adopted this, and other do not..
Running too hot will also cause pre-ignition, and the knock sensors will cause timing retard, loss of performance, and poor gas mileage...esspecially for those that can only get 91 octane gas.
keeping the car in the sweet spot is a function of a custom cooling system adjustment. I use a 160 stat and adjusted fan settings in my car from late April through September, thi9s keeps my car in the sweet spot through the summer. I use a stock stat and fan seeting through the fall and winter..
It takes five minutes to swap stats, with very little ( less than a pint of coolant loss).
This sweet spot concept is used by all tuners, that why they put a 160 stat and adjust fans settings in cars with mods. Summer driving conditions and a 160 stat will never allow your car to see actual 160 F coolant temps. Ambient air will not transfer heat when its 80 to 90 F.
a 90+ day on a black top road can yeild 140/160 F surface temps. So there is very little cooling from a bottom feeder air flow system. Your cooling system needs alittle help to gain optimum performance... Running Too Hot, is a definite NO NO........
Bottom line here..
Listening to wanna be mechanics and BS artist here on this forum can cause you serious damage and shortened engine life.. ben dover , You have no clue, and should not post about things you obviously know nothing about, especially about an LS1/6 engine.

TopCat

Hey E-T, I know you sometimes tire of replying to nonsense, but thanks for taking the time to debunk "ben dover" (cute name, eh? Following this one's advice is like being asked to 'bend over' )

Thanks again for helping all the newbies that are surely wondering the same thing about t-stats this time of year

Special K

Good morning Bill. I am pleasently surprised to see you. Great post.

We're doing a 'test and tune' at Bradenton tonight then down to Moroso for the Corvette Challenge on Sat. Come on down.

Free lodging at the Korreck's.

Bob

6Speeder

Evil: I see we agree on the use of a 160. Cool. Using that thermostat, and changing the fan settings, allows us to make the coolant temp stay where we want while cruising. You say the sweet spot is 190 to 200, and I accept that. However, to get that under WOT, with the stock cooling system, we had to start the runs a little cooler, as the temps climb during a run. On the dyno, the fans don't push as much cooling air as driving, so best power was made starting at 170, and at the drag strip I made best MPH when starting a little higher, 175 to 180. Starting a little cooler keeps the engine out of KR during that hard third/fourth gear WOT blast.

Everybody compromises somewhere, GM compromised to get lower emissions and long engine life. I chose to compromise to get a few more HP, and if the engine doesn't last 200,000 miles I really don't care. My Y2K has 20,000 miles on this engine combo. If it goes to 100,000 miles running this good, that's more than enough. If I have to de-carbon it in another 20,000 miles, that's the price I have to pay for performance, and that's OK also.

Av8ter

I agree with the temps youve stated and have made other posts regarding the cooling system and its function as well.

The ideal temperature is 190-200, so why change the thermostat? I have the stock thermostat and have the fans adjusted with LS1 edit and it runs exactly 194 degrees all year round in Texas heat with A/C on and in the coldest of winter, not that its that much of a cold winter here.

Evil-Twin

You can not tell me that sitting on a hot Texas highway with surface temps approaching 160F on a black top road, that you are getting any heat transfer. Having a 160 stat and fan settings in the 180 "ON" and 173 "off" gives you a head start on keeping the coolant an oil where it should be... turning the fans down below 190 with a stock stat will keep the fans on the on position, and they are not designed to run constantly... they have to cycle on and off... If you are doing all highway driving it isn't a problem, but if your doing city rural and highway driving then a custom stat and cooling program will give you optimum performance curve. If you ever notice Nascar uses duct tape to adjust for track temps so they can keep their cars in their "sweet spot" they add or remove duct tape to to adjust the air flow to the radiator and oil cooler...
the same principle applies here... you want your car to run at optimum performance than you need to customize it for your driving conditions, much like my tutorial on tire pressure. #30 psi cold in North Dakota in th winter @ -20F is not the same as 30 cold in Texas on a 110+ day.
cold temps are for cars that never move.... You want to have the right pressure when the car is moving so adjusting
the right temps has everything to do with the road temps during that season... 30 psi cold on a cool morning in Georgia can quickly turn into 36 psi in the afternoon when that Georgia blacktop hits 140/160 F. So why monitor cold tire pressure??? No one in the performance industry uses cold tire pressures. The tire sticker on the door is just to try to idiot proof consumers so they don't run Max tire pressures posted on the side wall..