Gains from T-stat?

**GottaHaveLS1** · 11-26-2007, 11:22 AM

I makin my Christmas list and I'm going to get some Motive Perf. 3.73 Gears and probably a lower temp t-stat. I know I'll need a tune for the t-stat to be in effect but will there be any noticeable gain? I've also seen some T-stats for as low as $16 and others are close to $50. What should I get??

Also, the gears will throw off my speedo right? whats the easiest way to fix that?

**JonB** · 11-26-2007, 11:37 AM

There will be no gain.

As for your speedo, anyone with editing software should be able to fix it for a small fee, or a handheld tunner can correct it as well.

**GottaHaveLS1** · 11-26-2007, 11:43 AM

So is it basically like a "free mod" that helps the engine generate more power in theory??

Also what about the price variation? I've seen on some sites that it says 2004-07 ls1/2 t-stat for $16 and the 97-02 t-stat is $45. whats the deal with that?

**Firebirdjones** · 11-26-2007, 12:33 PM

I'm not going to say there is a HP advantage to a cooler thermostat, but there are many more advantages that I see which is why I run one in every car we own, even the daily drivers.

I like the cooler thermostats for the simple reason that it's common knowledge that a cooler engine will help ward off detonation,,,and with an aggressive tune and the crappy pump gas getting even worse as we speak,,,every little bit helps in that department and it's just a piece of mind for me.

Other things I like as well is the fact that if the engine is running cooler, then all the other components run cooler as well. The transmission is cooler to some degree,,,,,the air intake setup stays a little cooler,,,,in general the underhood temps will not be as extreme,,,and thats a good thing. With cooler underhood temps all the rubber and plastic hardware (ie: belts and hoses for example) will have a longer life span or at the very least an easier life span compared to extreme heat. If your 4th gen has the power steering cooler it will run cooler as well,,,,since it uses the engine coolant.

All this alone is worth it to me,,,I really don't care if there is a HP gain or not. On the other hand,,,being able to be more aggressive on the tune up with a cooler thermostat might be worth a few ponies.

**GottaHaveLS1** · 11-26-2007, 04:51 PM

Originally Posted by Firebirdjones

I'm not going to say there is a HP advantage to a cooler thermostat, but there are many more advantages that I see which is why I run one in every car we own, even the daily drivers.

I like the cooler thermostats for the simple reason that it's common knowledge that a cooler engine will help ward off detonation,,,and with an aggressive tune and the crappy pump gas getting even worse as we speak,,,every little bit helps in that department and it's just a piece of mind for me.

Other things I like as well is the fact that if the engine is running cooler, then all the other components run cooler as well. The transmission is cooler to some degree,,,,,the air intake setup stays a little cooler,,,,in general the underhood temps will not be as extreme,,,and thats a good thing. With cooler underhood temps all the rubber and plastic hardware (ie: belts and hoses for example) will have a longer life span or at the very least an easier life span compared to extreme heat. If your 4th gen has the power steering cooler it will run cooler as well,,,,since it uses the engine coolant.

All this alone is worth it to me,,,I really don't care if there is a HP gain or not. On the other hand,,,being able to be more aggressive on the tune up with a cooler thermostat might be worth a few ponies.

I see what you mean. I'll definitely be getting it. Does anyone know why the 04-07 (c5/c6) t-stat is much cheaper than the 97-02 t-stat??

**Firebirdjones** · 11-26-2007, 04:58 PM

Originally Posted by GottaHaveLS1

I see what you mean. I'll definitely be getting it. Does anyone know why the 04-07 (c5/c6) t-stat is much cheaper than the 97-02 t-stat??

I haven't layed eyes on the 04-07 stat but I am going to guess it's a different design.

I know the 97-02 stats come in a complete housing, water neck and all that simply bolts onto the water pump,,,hence the reason for the high cost.

Thats how mine was delivered.

**JonB** · 11-27-2007, 12:56 PM

Originally Posted by Firebirdjones

I haven't layed eyes on the 04-07 stat but I am going to guess it's a different design.

I know the 97-02 stats come in a complete housing, water neck and all that simply bolts onto the water pump,,,hence the reason for the high cost.

Thats how mine was delivered.

I beleive you are correct. I have not layed eyes on 04-07 either but I'm guessing they don't come with the complete houseing like the 97-02.

As far as the engine running cooler= more power you may want to do a search. There are multiple threads on the subject and it has been proven that ls1's make more hp at higher operating temps. I believe it was close to the 200 degree mark that it made the most power.

**Firebirdjones** · 11-27-2007, 01:15 PM

Originally Posted by JonB

I beleive you are correct. I have not layed eyes on 04-07 either but I'm guessing they don't come with the complete houseing like the 97-02.

As far as the engine running cooler= more power you may want to do a search. There are multiple threads on the subject and it has been proven that ls1's make more hp at higher operating temps. I believe it was close to the 200 degree mark that it made the most power.

That may be,,,but I don't really buy into that. There are too many other advantages that appeal to me that I mentioned above, plus my own dyno and track testing has proved otherwise. I believe the biggest reason GM and other manufactures install such hot thermostats in these cars is simply to burn off more emmissions,,,it helps them to meet the ever more strict EPA requirements. Although as I mentioned cars that are on the edge of detonation it's common knowledge that a cooler engine can help combat that problem,,,and possibly get more aggressive on the tune as well. One reason why all the handhelds out there recommend a cooler stat before installing there most aggressive tuneup.

On another note I have always made more power in my older muscle cars while having the engines on the dyno with a cooler operating temp that is easily adjusted with the water tank,,,,and they also run better at the track after a full cooldown as well,,,,,so I have just stuck with a cooler stat throughout the years with no ill affects at all.

As a matter of fact,,,,I recently ran my 02 SS and right off the street with no cool down,,,and logging a temp of 186 on the starting line,,,,it ran 13.46 at 104 mph. I decided to let the car cool,,,,logging again this time the temp was 166 degrees at the starting line and the car went 13.31 at 105 mph.
My big block chevelle and my 70 firebird also react the same way so I see no reason to run a hotter thermostat in my situation,,,,unless you want tremendous amounts of heat coming from the heater to keep you warm in a cold climate maybe. But even here in Ohio where the temps can be in the teens or even below zero I still use a 160 stat in my daily drivers with no problems, and still get plenty of heat to keep me comfy.

**JonB** · 11-27-2007, 02:27 PM

My whole point is there are alot of things to consider when it comes to going to a 160 t-stat. I don't 100% back the whole it makes more hp at higher temps although back in the day when it first came about there were some facts to back it. That subject has been beaten to death but alot of those threads have some good info on lower temp t-stats for the original poster or others looking at this thread.

Fan adjustement is very important, with out adjusting them you are wasting your time and money on a 160stat . The area you live can take a role in what t-stat you go with. I've ran 160's in small block chevys here in fl and the car never reached proper operating temp causing the torque converter to kick in and out of lock up and not run well. I'm running a 160 in my z28 but am thinking of going to a 180. In the summer I still run in the 195-200(in traffic) range with the proper fan setting. In hot temperatures a 160 very often will never close and can cause overheating problems, it would be close to not running one at all. Which I think is why my car runs so hot in the summer the t-stat is open all the time not giving the coolant time to cool in the rad.

**Firebirdjones** · 11-27-2007, 05:33 PM

Originally Posted by JonB

My whole point is there are alot of things to consider when it comes to going to a 160 t-stat. I don't 100% back the whole it makes more hp at higher temps although back in the day when it first came about there were some facts to back it. That subject has been beaten to death but alot of those threads have some good info on lower temp t-stats for the original poster or others looking at this thread.

Fan adjustement is very important, with out adjusting them you are wasting your time and money on a 160stat . The area you live can take a role in what t-stat you go with. I've ran 160's in small block chevys here in fl and the car never reached proper operating temp causing the torque converter to kick in and out of lock up and not run well. I'm running a 160 in my z28 but am thinking of going to a 180. In the summer I still run in the 195-200(in traffic) range with the proper fan setting. In hot temperatures a 160 very often will never close and can cause overheating problems, it would be close to not running one at all. Which I think is why my car runs so hot in the summer the t-stat is open all the time not giving the coolant time to cool in the rad.

Hmmmm, interesting because I have never experienced any of those problems in either sub zero temps or 100 degrees outside.

My converter locks before I get to the end of the street with the 160 stat. Actually when I have the scanner on for a cold start run,,,,the converter locks up once the engine hits about 130 degrees,,,and I haven't messed with this setting so I would assume all the 4th gens should be in this area,,,,which the 160 thermostat shouldn't be affecting.

As far as running hot because the stat is always open in the summer time? Hmmmm I haven't had a problem,,,although when I installed an underdrive pulley the car ran hotter,,,which slowed the pump down and should fix the problem you describe,,,,leaving the coolant in the radiator longer,,,,but it actually made my car run warmer. I personally don't like it and plan to take that back off.

You do bring up a point that everyone should consider though,,,,adjusting the fans. With these 4th gens it's important to have the fans programmed to run a little above the area the stat operates. The cooler stat will work without changing the fans,,,,but you will only see the cooler engine temps when the car is moving and getting air accross the radiator,,,once in traffic the temps go back up to the 220 range where the factory fan settings are. Once moving again the car will cool back down,,,but getting the fans set so there isn't such a drastic change is the way to go.

Now most everything I just said doesn't even apply to an old car,,,,those are much easier,,,,drop the stat in and go. I really miss the simple days,,,,lol.

**nhraformula** · 11-28-2007, 07:47 AM

a t-stat minus tuning is wasting your time.

**Firebirdjones** · 11-28-2007, 10:19 AM

Originally Posted by nhraformula

a t-stat minus tuning is wasting your time.

Ya as far as the fans are concerned I agree.

**GottaHaveLS1** · 11-28-2007, 08:45 PM

Originally Posted by Firebirdjones

Ya as far as the fans are concerned I agree.

Is that all the T-stat does? Because I had a street tune and the tuner told me he also lowered the temperature that the fans will turn on. Does that mean I won't need a t-stat?

**Firebirdjones** · 11-29-2007, 03:16 AM

Originally Posted by GottaHaveLS1

Is that all the T-stat does? Because I had a street tune and the tuner told me he also lowered the temperature that the fans will turn on. Does that mean I won't need a t-stat?

I would go back to that tuner and specifically ask him what he did to your fans. As far as I am concerned simply lowering the fans temps without a cooler thermostat won't do anything for you. Since these things have a 195 degree thermostat from the factory,,,if that is indeed what you still have,,,,then you couldn't ideally lower the fan temps below that anyway.

The factory fan setting are around 215 or 220 degrees. I would have to look at a stock bin file to verify but that is a close ballpark. Theoredically you could lower the fans slightly to around 210 degrees or so depending on how your thermostat cycles,,,but why bother with the stock thermostat. Thats hardly a change at all.

If you want the lower fan temps then I suggest going with the 160 stat which will actuall cycle around the 170 degree range,,,,and then set the fans accordingly. If your going to make a change,,,,I would make something more noticable. Might want to verify what stat your car has first and ask your tuner where he set your fans as well. If you have access to a scanner, go for a drive and watch the temps, you can watch the temp cycle and the fans cycle as well,,,this will give you an idea what thermostat may be in the car and where the fans are set as well.

**ApexVIII** · 11-29-2007, 06:39 PM

go with a 180 t stat i hears the 160 is to low and it will run rich

**SSTODD** · 12-03-2007, 07:50 AM

Factory stat. is 187, not 195. Do not believe what the gage is pointing at, it is a glorified idiot light after 98.

**sunsetorangess** · 12-03-2007, 08:02 AM

Like said above its not gonna add gob's of Hp but it will keep everything cooler if you have the fans adjusted.
Also the price differece which u asked above is because Most retailers sell our thermo's with the housing. Thats why there somewhat pricey.
J

**Firebirdjones** · 12-03-2007, 10:35 AM

Originally Posted by ApexVIII

go with a 180 t stat i hears the 160 is to low and it will run rich

Didn't cause that problem on any of my cars. Besides if it did I am sure a few small changes in the tune would cure that anyway,,,take care of that when your in there adjusting the fans.

**Firebirdjones** · 12-03-2007, 10:37 AM

Originally Posted by SSTODD

Factory stat. is 187, not 195. Do not believe what the gage is pointing at, it is a glorified idiot light after 98.

I don't use the gauge,,,,I use the HPtuner scanner with the laptop sitting next to me. Has a real nice gauge display that tells you exactly what the computer is picking up. With the stock thermostat my car never ran at 187 degrees. It was always over 200 degrees with factory fan temps set around 220 degrees. Unfortunately the original thermostat I pulled out doesn't have any temperature reading stamped in the housing that I can see like the old cars do,,,but if it was a 187 thermostat,,,,it sure as hell didn't operate in that range.