Lone Ranger

I've heard that in most street driving you only see about 10 degrees cooler temps going down the road when running a 160 tstat. That can't make that much performance difference or do any harm. What the 160 does help with is keeping your coolant temp from spiking up to 230F when caught sitting in traffic etc., provided your fans come on earlier via a manual switch or ECM programming (or flipping the air conditioning on).

So I postulate that in the sense that the 160 narrows the temperature fluctuation range significantly (no more going from 194F in driving to 230 at the stoplight, then back down again, then back up, up/down, up/down, up/down) it therefore helps *protect* the engine in the long run, because: we have (well I have an a lowly LT1, you guys have the LS1) aluminum heads mated to an iron block which means each metal cools at a different rate and therefore their expansion/contraction rates are also not the same which with regular large temp differentials = bad in the long run, IMHO. The 160 by keeping the engine from heating up so high in traffic therefore makes life easier on the heads, etc.

I'm not an engineer, but I did stay at a Holiday Inn Express lastnight :D


[Modified by Lone Ranger, 5:27 PM 7/25/2002]

BAD2BNE

LMAO!!!! Hey, I stayed at one of those once too :yesnod:
Great point Lone Ranger :cheers:

C5-VERT

With my 160 and Fans speeds controlled by LS1 Edit my temps range from 176 - 195 depending on driving situation and whether the air conditioning is on. The car definately feels more consistent than when my temps use to jump between 210-230. Depsite all of the bad hype I would not even consider taking it out... :nono:

Mako

I run the 160 degree stat and have no problems whatsoever. My car also has the DRM HD radiator and engine oil cooler. There is no problem exceeding 160 degrees. Oil and coolant temps heat up just fine.

irfgt

Since I own two scan tools, OTC and Snap On, I hooked up to my 2003 and started the unmodified engine cold and held the throttle at 2000 rpms and at 93 degrees it went closed loop and well before 5 minutes. The 2000 rpms gave the 02 sensors a faster warm up which means to me that the computer was waiting to see the coolant temp setting for the closed loop signal. Older GM cars would need to see around 135-140 degrees to close loop but the heated 02 sensors close the gap.

6Speeder

JIMMAN: So let me git this straight: You slam me for quoting quarter mile results as being too uncontrolled, too many variables, and talk (as an engineer) about 6 dyno runs and controlled testing. Then you say your data was from multiple cars (now that's controlled testing) and "my 00 ran best over 200 " so that is where you run your 02. That is not even uncontrolled testing that is NO TESTING. And you say that lower isn't cutting it, over 200 makes more power, but then admit that from your data the hp gain or loss isn't significant. If it wasn't significant, then why jump in with an opinion (not facts, cause you have no "significant" data) at all? Sorry dude your testing isn't cutting it.
:seeya

BAD2BNE

irfgt: Thanks man!....It's good to have a real life use test to back up what I've been saying. :cheers:
I'm still waiting for jimman to tell me why I'm wrong. :eek:

jimman

6speed, I suggest you learn how to read, I've owned 2 C5's over the past 3 years and have just done testing with the 00 because I just got the 02 3 weeks ago and since there are over 40 guys dynoing last time I didn't have the luxury of being able to do as many controlled pulls. Since in the past the temp was proven to be best with a warm engine why not continue since they are almost Identical. I'm still checking my computer since I'm on computer number three and I've been traveling bear with me on the data of 176. These discussions are not new and have been hashed over many many times over the past 3 years on this forum. Halltech has done a ton of testing with this also there are some other web sites that will contribute to this. I speak from what I learned and if that is a problem with you guys than so be it. If you want I will send you the 10 or so dyno sheets showing you results that is if your concerned. I think you will find that the main difference is a stable pull when your at temp and that is all. If you still think that at the track will let you tell the difference between 5 to 10 hp then your sences are far superior to me and every other human that I know of. Also, last numbers for the 00 were, 319 rwhp at 328.6 ftlbs cold 1st pull, and 322.2 rwhp at 333.9 ftlbs hot and final pull. The 02 came in at 305.2 rwhp at 328.6 ftlbs cold 1st pull and 308.5 rwhp at 329.8 ftlbs hot final pull. The 02 is stock and was run for a baseline the 00 had only the intake changed.


[Modified by jimman, 9:30 AM 7/26/2002]

McRat

You CAN feel and record 10hp changes at the track. Been there, done that. Uncapped cutout (8hp) and ran 0.1 and 1mph. Capped it, and lost it again.

To get a car to run 1 second quicker, most guys do it 0.1-0.2 at a time. Unless you have deep pockets or N20.

The goal of a 160 therm is not to make more horsepower. It's to avoid losing the HP you have. It's really important AutoX'g, where you are often 30-40mph at WOT under load. At the end of a 60 second run, even with a 160, you'll see 210 deg.

BAD2BNE

You are correct. These discussions are not new to this Forum because different and new people ask them each time. :yesnod:
The one BAD thing that is also consistant during these discussions is the wrong information being given out as gospel so the one who asks the question never gets the correct information :mad
I've given you two separate sources of information to back up what I say about the closed loop temperature on an LS1 directly from the GM Service Manual and now another member has used his own scan tool and performed and 'controlled' test and his results have backed me up. But you still want to say I'm wrong.
Is it that you truely believe you are correct or can you not admit when you are mistaken?....
Perhaps C5-Tech or C4C5Specialist should help here to enlighten you. But would you even believe a specialist in this matter??
You keep slamming us who disagree with you but have no factual data to back up your statements. This is the very reason I have so few posts on this Forum. I've never found it productive to even try to give people honest and true information!
:cheers: Have a good day.

jimman

I don't believe I slamed you other than state actual tests I've done and witnessed and I've offered you the data but it goes un-noticed. Use the 160 if you wish I just don't want to have to be the one who buys the car after you used it that's all. You want to run the car rich that's your choice. I'm sensitive to people saying that "GM doesn't know what they are doing use my solution". I have a friend that took people for their word on suspension, shock, solutions and now, do to accident is half metal.

I referenced the 176 as per the ECM reset procedure for resetting and idle reset. Pull fuses reinstall, idle till close loop temp of 176 is reached then let run for 5 full minutes and shut down. There are other inputs that contribute to close loop this is one in a benign event. Sorry if your all offended but disscusion groups are for this purpose, to state your point of view. I've did the 160 on previous C4's and found no use what so ever to that mod. It is even less an effect with an aluminum engine because of it's higher thermal conductivity factors. I would focus more on a different fan setting than bothering with a therm to screw up your mixtures. If this is again a problem for you all I appologize in advance.

jimman

Also, correct me if I'm wrong, but the documents you are all stating as bible, I think recommends the 190 thermostat. I guess we can pick and chose which we believe???

6Speeder

You know, I would not even grace you with a reply except for the fact that, as bad2bne correctly states, YOU KEEP GIVING OUT BAD INFORMATION. Others read this and could, foolishly, believe you. The C5 PCM goes into closed loop operation at far lower temps than you seem to think. You have been provided the correct info, with references. Why do you persist? As for your assertion that my 2000 will run rich because it's running cooler, again you're wrong. The autotap and Ease scan runs show that it's running as it should. As for the two dyno runs you cite without telling us the coolant temps, and show a whopping 3 hp difference, you're right, THAT IS NOT SIGNIFICANT. You'll see more data spread for identical outputs due to dyno limits of accuracy alone. BTW: I did learn to read, and at my school, I learned grammar, and proper work choice. I suggest remedial english would help you. Have a nice day. :lol:

jimman

You say I give bad info, your documents say 190 not 160. If you want to demean me as a person give it your best shot but at least respond to what has been written. The first runs were done at precisely 190 and the third was at 200.

BAD2BNE

jimman: This is the last time I'll post to this thread since it's going nowhere but down the toilet. :rolleyes:
The last point I'll make to you is that my total and complete discussion with you has been in regard to your statement that 176 degrees is the closed loop temperature on the LS1 engine in your very first reply to the poor individual who started this thread. I have never stated that the 160 or any other t-stat was better than another. I did state that the 160 t-stat would not hurt the engine or keep it in open loop and that is fact. In fact, if you had bothered to look at my signature in my first post, you would notice that I use a 172-178 t-stat and that I DO use a fan controller. If you would understand that closed loop is reached at 93 degrees, then you would also understand that it is impossible for any thermostat that lets the coolant temperature get higher than 93 degrees to cause the engine to run rich because of keeping the engine in open loop. :nono:
Since I've never argued with you about the use of any individual thermostat that would open at any temperature, but have pointed out that your statement about the temperature that an LS1 engine reaches closed loop is in error, you have failed to document or point out how I'm wrong in contesting your erroneous informational statment.
And don't worry about ever being the guy who would buy my Vette....It will never be for sale. :D
Good by. Have a good life. But please give folks who are looking for good information to help them with their Vettes, the correct information in the future. :cheers:

jschindler

You have run this thermostat for two years with no problems. Ask the guys who tell you it's bad how long they have run one and EXACTLY what problems THEY have had.

Power Shifter

I have been useing 160ts in my car's before some of you had the legal right to drive.(bell bottoms were in style:D) I have not had ANY problems EXCEPT my cars are usualy faster than others. Three C5's with aluminum moter and no mechanical problems and all with 160's. It's tiresome reading some of the bs. The sad thing is most of the experts putting the bs out run slower or not at all. Ric

XKR100

:yesnod: :yesnod: :yesnod: :yesnod:

QuickSilver2002

To clarify the closed loop thing once and for all (if that is possible on this forum):

In '01 and up pcms(i'm looking at the data now), the closed loop operation enable temp is set in a table (air temp vs coolant temp).

The table data I'm looking at seems to indicate that any air temp above (-28*F) will only require a coolant temp of 92*F to go into closed loop. Below -28* (who would drive a corvette in those conditions) requires a coolant temp of 140*.

So the guy talking about 170* temps is way way off.

I totally agree with some of the others who posted about the purpose of a 160* stat. 160 is the only way to go in the summer months if you are doing any competitive driving. Not that 190* is a bad temp, just that you need the lower stat to keep the motor out of the power robbing temps above 200* where the #s seem to get very erratic. I have experienced this several times and the 160* with new fan settings solves it. Also, if you have not figured it out by now, coolant temp is not the all telling temp for the motor. It's not that simple of a system.

jschindler

Actually, what this post really tells me is that while everyone is focused on the thermostat temp, the fans comming on early is what really makes the big differnce. If you are trying to keep your engine in the 190's, it does not matter which thermostat you use. It's when the fans come on that counts. You only need a lower thermostat if you want the temp to stay below the temp of the stock thermostat.