: 180 degree performance thermostat



RobertCTS
07-26-04, 05:10 PM
A cooler engine produces more horsepower. The manufacturer uses a 195 degree thermostat to meet emissions. I'm having trouble finding a 180 degree thermostat for the CTS 3.6 :hmm: Can anybody help me?

benjet
07-26-04, 05:16 PM
A cooler engine (below designed operating tempurature) also increases wear exponentially, and in the case of many GM products lowers chasis dyno #'s, just FYI.

-Ben

RobertCTS
07-26-04, 07:21 PM
A cooler engine (below designed operating tempurature) also increases wear exponentially, and in the case of many GM products lowers chasis dyno #'s, just FYI.

-Ben

Ben
Contrary to what I know. Maybe you can share your info source?

miscreant
07-26-04, 07:49 PM
A cooler engine produces more horsepower. The manufacturer uses a 195 degree thermostat to meet emissions. I'm having trouble finding a 180 degree thermostat for the CTS 3.6 :hmm: Can anybody help me?

Typically, therms also require a reprogrammed ecm to work effectively.

StealthV
07-26-04, 08:14 PM
A cooler engine produces more horsepower. The manufacturer uses a 195 degree thermostat to meet emissions. I'm having trouble finding a 180 degree thermostat for the CTS 3.6 :hmm: Can anybody help me?

Cooler intake air is what makes power due to an increased density, not a cooler engine block. An engine actually makes more power and becomes more efficient the hotter it becomes. The trick is to get the engine really hot, but not to the point of melt down of the components.

Hence manufacturers utilize pressurized coolant systems which raise the boiling point of water, allowing increased engine operating temperatures before the coolant changes state from a liquid to a gas. "Simple" thermodynamics. :)

dkozloski
07-26-04, 08:29 PM
A complicating factor is that as an aluminum cylinder block expands, the deck height becomes higher and the compression ratio lowers. The old ZL-1 427 Chevy aluminum big block engine actually developed lower horsepower than the L-88 427 cast iron engine when both engines were hot. The only important difference between them was the aluminum block. Esoteric to be sure.

RobertCTS
07-26-04, 08:31 PM
Cooler intake air is what makes power due to an increased density, not a cooler engine block. An engine actually makes more power and becomes more efficient the hotter it becomes. The trick is to get the engine really hot, but not to the point of melt down of the components.

Hence manufacturers utilize pressurized coolant systems which raise the boiling point of water, allowing increased engine operating temperatures before the coolant changes state from a liquid to a gas. "Simple" thermodynamics. :)

Curious. Why is there such a market for these therms? I can't find the one for the CTS but many for others like the small block Chevy. They do promise increased HP.
Check out this link and tell me what you think?

http://www.martelbrothers.com/customer/product.php?productid=HYP1018&cat=589&page=1

1500cc
07-26-04, 09:07 PM
A lower temp thermostat works by making the ECM provide a richer fuel/air mixture. Why does this make more power? Because an engine's power is limited by the amount of oxygen it can combust, not fuel (it's easy to add more fuel but the amount of oxygen in the cylinder is fixed). If you had a mixture that on average was stoichiometric, there would still be pockets that were a bit rich and pockets that were a bit too lean to burn. By creating a richer overall mixture, you ensure that those slightly lean pockets have enough fuel to burn, and therefore you are combusting all of the oxygen possible and making max power.

This was more of an issue on older cars with poorer combustion control. On modern engines there's not nearly as much to be gained by a cooler thermostat.

StealthV
07-26-04, 09:20 PM
There's a market for them because people, like yourself, believe it is better. People will sell you anything to make a buck.

One can't argue with Newton's Second Law of Thermodynamics. The higher the difference between the intake air and engine temperature, the more power and efficiency. It's all in here --> Thermodynamics of a Gasoline Engine (http://www.seas.upenn.edu/~meam100/handouts/Thermo.pdf)

Because of the physical laws of the universe we live in, nothing is free, there is always a trade-off. Just like K&N filters - sure they flow more air, the trade off? They don't filter dirt out of the air stream as well as a paper filter.

benjet
07-27-04, 03:44 AM
Thank ya StealthV for backing me up between visits to my screen ;)
-Ben

RobertCTS
07-27-04, 07:28 AM
There's a market for them because people, like yourself, believe it is better. People will sell you anything to make a buck.

One can't argue with Newton's Second Law of Thermodynamics. The higher the difference between the intake air and engine temperature, the more power and efficiency. It's all in here --> Thermodynamics of a Gasoline Engine (http://www.seas.upenn.edu/~meam100/handouts/Thermo.pdf)

Because of the physical laws of the universe we live in, nothing is free, there is always a trade-off. Just like K&N filters - sure they flow more air, the trade off? They don't filter dirt out of the air stream as well as a paper filter.

Stealth:
Forum etiquette- "people like yourself" will buy things that don't work. It finds it's roots from P.T. Barum, "A fool is born every minute." I'm not a fool.

Stealth, I hear what you're saying and in part it make sense to me. But figure this out. I'm a drag racer from the sixties. I raced Corvettes. We took what GM gave us; big powerful motors, fresh pressurized air from the base of the windshield and waste gates on the side fenders to extract heat.

At the drag strip we saw engine heat as the enemy. We did everything we could to keep the engine compartment cool. We drove up to the staging area with our hoods popped to let the heat escape. Between runs we opened up the engine bay, packed the intake manifold, carb fuel bowls and gas lines with ice bags. We wrapped our headers with insulating tape and a common thing to do was to install low temp thermos. All of this was to reduce engine heat and cool the fuel. All I gotta say is it worked. We were FAST!

Have you looked at the CTS-VR's closely? Look at the hood. Two HUGE holes! The intake is the reverse of a scoop. That serves two purposes. Mainly it quickly removes heat and adds cool air.

This a forum of dialog. A place to share ideas. It can be a pleasant place.

briandors
07-27-04, 04:25 PM
You guys need to re-read Miscreant's post.

The ECM may at first dump in more gas, but it will soon start to lean things out again. It will re-learn the proper (or programmed, speaking more accurately) A/F ratio based on all the sensor readings.

That's the 30,000 foot explanation, I'm sure someone here can get into the nuts and bolts of O2 sensors working with Engine temp, timing, etc. that makes this happen.

Brian

RobertCTS
07-27-04, 05:08 PM
You guys need to re-read Miscreant's post.

The ECM may at first dump in more gas, but it will soon start to lean things out again. It will re-learn the proper (or programmed, speaking more accurately) A/F ratio based on all the sensor readings.

That's the 30,000 foot explanation, I'm sure someone here can get into the nuts and bolts of O2 sensors working with Engine temp, timing, etc. that makes this happen.

Brian

I read Miscreant's post. He's a cool guy and well informed. I just wanted to discuss the applications that could make the CTS faster. But I think you may be right. GM has come a long way to discourage us hot rodders with the ECM.

A website called dyno-proven.com has been working on ways to change and improve the CTS ECM. They have found it to huge challenge. And these guys are very good at what they do!! Thanks for the input Brian.

tzoid
07-27-04, 08:38 PM
A quick reply to ROBERTCTS....Nice to meet a fellow racer from the '60's. Been there, done that (as our kids say!), worked on original '67 dual 4bbl Z28's, 396 Chevelles (up to 375 hp), Boss 302 Mustangs, '68 & '69 Hemi Roadrunners, bunches of 442's and GTO's. Todays engines...totally different, infinitely better in every respect. More hp/cube, more efficient, just plain better with todays technology. Cool was important in the '60's with simple modified stock type engines. Those louvers on the CTS V are to equalize air pressure from under the hood to prevent the hood from blowing open at high speeds...believe it or not! The design for them has no consideration at all to let the engine run cooler. Unless a modern day car is modified significantly (a.k.a. won't pass state inspections), running the standard, stock thermostat will generate maximum hp. Been tested many times. Owners in the very southern states and places like Arizona like the low temp 'stats because it gives them more breathing room when your driving in traffic, a/c on and the outside air temp is 110-115. Otherwise, waste of money and probably will reduce performance a wee bit. Don't you love today's technology!!!

RobertCTS
07-28-04, 05:23 AM
A quick reply to ROBERTCTS....Nice to meet a fellow racer from the '60's. Been there, done that (as our kids say!), worked on original '67 dual 4bbl Z28's, 396 Chevelles (up to 375 hp), Boss 302 Mustangs, '68 & '69 Hemi Roadrunners, bunches of 442's and GTO's. Todays engines...totally different, infinitely better in every respect. More hp/cube, more efficient, just plain better with todays technology. Cool was important in the '60's with simple modified stock type engines. Those louvers on the CTS V are to equalize air pressure from under the hood to prevent the hood from blowing open at high speeds...believe it or not! The design for them has no consideration at all to let the engine run cooler. Unless a modern day car is modified significantly (a.k.a. won't pass state inspections), running the standard, stock thermostat will generate maximum hp. Been tested many times. Owners in the very southern states and places like Arizona like the low temp 'stats because it gives them more breathing room when your driving in traffic, a/c on and the outside air temp is 110-115. Otherwise, waste of money and probably will reduce performance a wee bit. Don't you love today's technology!!!

Tzoid,
Yep, It's difficult to build a fast car today! Any changes and the ECM gets confused and the engine doesn't run well. Shade tree mechanics are now dinosaurs.
About the CTS-VR hood. I don't understand your comment. Wouldn't that apply to all the race cars; the Audis, BMW etc? No massive hood openings on those cars. :hmm:

Justin83NJ
07-28-04, 07:39 AM
Stealth:

At the drag strip we saw engine heat as the enemy. We did everything we could to keep the engine compartment cool. We drove up to the staging area with our hoods popped to let the heat escape. Between runs we opened up the engine bay, packed the intake manifold, carb fuel bowls and gas lines with ice bags. We wrapped our headers with insulating tape and a common thing to do was to install low temp thermos. All of this was to reduce engine heat and cool the fuel. All I gotta say is it worked. We were FAST!

Have you looked at the CTS-VR's closely? Look at the hood. Two HUGE holes! The intake is the reverse of a scoop. That serves two purposes. Mainly it quickly removes heat and adds cool air.



I'm a mechanical engineering student and I can contribute here a little bit.

With all other things being equal, operating at higher temperatures and higher compression, etc. do contribute to increased efficiency (more power). With that said, there are many other variables which produce a certain range of temperatures where the engine would be most efficient. For instance, with increased temperatures undesired effects like detonation can occur.

Wrapping headers with insulation is not merely to keep the engine bay cool; it is to keep the headers hot. The hotter the exhaust gas is, the higher pressure it has to get out. Hotter exhaust gases flow faster.

Also, nobody will argue with you that the cooler the air coming into the engine the better. Cooler air is denser, which means more oxygen in the same volume of air. More oxygen means more fuel must be delivered for the stoichiometric mixture (not rich and not lean). This increased fuel and air results in more power.

Intercooling a turbocharged engine increases an engine's efficiency tremendously and thus adds a lot of horsepower. For different types of engines, there is also a process called "reheating" which greatly increases efficiency as well. Power plants have these engines which have intercooling and reheating.

RobertCTS
07-28-04, 09:11 AM
Justin
Thanks for your input. I'm familiar with intercooling but share with us about REHEATING?

KadKat
07-28-04, 10:45 AM
I'm not an engineer and I don't play one on TV either. This is an interesting discussion but with addition of sensors and computers to control a vast amount of items in the engine process, it's getting difficult to find areas to overcome the engineering built in to today's vehicles. :hmm:

I think the biggest frustration today's shop jocks are experiencing directly related to all these items are more emission related than the manufacturers intention to detune our vehicles just for grins.

With that said, there are many discussions across the internet vehicle groups discussing virtually all these aspects. I came across this this morning and it helped me to better understand the greater picture.


GM MAF Stuff (http://www.gmtips.com/3rd-degree/dox/tips/maf/maf-screen.htm)

Justin83NJ
07-28-04, 03:17 PM
Justin
Thanks for your input. I'm familiar with intercooling but share with us about REHEATING?
I didn't mean to take this thread so far off-topic, but reheaters are often a part of gas-turbine engines. In a gas-turbine engine, air goes through a compressor, is burned with fuel in a combustion chamber, then the exhaust gas turns a turbine.

To make these more efficient, often the air is intercooled after the compressor and is then compressed again before it is combusted.

On the other end, the hot exhaust gases turn a turbine, losing heat. Then the gas is put through a reheater and the reheated gas turns another turbine.

RobertCTS
07-28-04, 05:33 PM
I didn't mean to take this thread so far off-topic, but reheaters are often a part of gas-turbine engines. In a gas-turbine engine, air goes through a compressor, is burned with fuel in a combustion chamber, then the exhaust gas turns a turbine.

To make these more efficient, often the air is intercooled after the compressor and is then compressed again before it is combusted.

On the other end, the hot exhaust gases turn a turbine, losing heat. Then the gas is put through a reheater and the reheated gas turns another turbine.

Justin,
Oh my! I hadn't about turbines in some time. Thanks for the update :)

tzoid
07-28-04, 09:04 PM
RobertCTS....It is real difficult to upgrade HP levels in the newer cars unless your a very intelligent, up to date tuner, generally in business to do just that...super tune cars. These guys are around in the car community, but generally focus on high volume cars that are typically owned by people who like to spend money on making their cars quicker. Mustangs, Corvettes, Camaros/Firebirds and the like have had the priviledge of spending mucho bucks with these guys for years...some of these guys are brilliant with their upgrades, many of which have been adopted by the manufacturers. Unfortunately, the CTS community is rather small yet and has apparently not shown any significant interest in this area, hence no one is in the business as yet. I have a Viper and there's only a handful of tuners in the market...the car's production levels have stayed low since inception (less have been made since it was introduced then Corvettes made in any single year) and the Viper tuners typically charge 3 to 4 times for the same mod that is available for any of the above toys! On your louvers question, it's not unusual to find these on cars that are raced that attain high speeds...150mph and above. Can't tell you why the BMW's, Audis, etc. production jobs don't have them, but if you look closely many have them that are in professional racing functions. Keep in mind as well, many of today's higher hp cars have speed limiters (fuel cut offs, etc.) built into their ECM programming to limit top speed. Just too dangerous for the casual owner.

RobertCTS
07-29-04, 05:35 AM
Wow! :bonkers: You gotta Viper?! You don't need to soup up your CTS for thrills.

tzoid
07-29-04, 09:30 PM
Let me see if I can figure out this thing....

\image{cars}

tzoid
07-29-04, 09:32 PM
Well, can't figure out how to post a picture! If anybody has the time, let me know! Thanks..........

1500cc
07-29-04, 09:48 PM
Well, can't figure out how to post a picture! If anybody has the time, let me know! Thanks..........
You need to host it on a web server somewhere (not your own computer). Your ISP probably gives you webspace; that's the perfect place to put it. Then you just need to link its address inside the IMG tags.

tzoid
07-29-04, 10:18 PM
1500cc....thanks much for the response. Unfortunately, haven't refreshed my Latin class in 40 years and the translation of what you wrote completely escapes me! I'll email you the pictures and you can post them for me! If not, just delete them......Thanks!!

tzoid
07-29-04, 10:19 PM
Oh well, screwed again! System won't let me email you! Thanks anyway!

RobertCTS
07-30-04, 06:01 AM
Oh well, screwed again! System won't let me email you! Thanks anyway!

TZOID,

Let's see if I can help. At 1st it seems difficult but as you get the hang of it, it becomes easy.

1st I assume you have software for "Photoshop" "Picture it" or "Corel".
Save your picture to "My Documents" in "My Pictures". (With me?)
Go to your "Photo Shop". It will ask you where your picture is, like your scanner or your computer. Click your computer. This should bring up your saved documents and click on "My Pictures". Click on the picture you want.

Now we need to reduce the picture to 50KB for the Forum site. One way is to reduce the picture size. Click "Change Page" Click "Crop Page". Crop out all the junk you don't really need. Click done. This is usually still to big. Click "Change Page" again. Click "Change Size". Reduce the picture down around 2x3. Click done.

Now you should have a pic you can post. Click "SAve As" Give it a name plus a number. This way you tell you old picture from your new one. If your new file is still to big and you have to go back and reduce it more, you give it another number. Nothing worse than going to your pictures and you have several pics that look a like.

That's the hard part. Now you have to post your pic.
Start you post dialog. When ready to post scroll down to heading that says "Manage Attachments". Click the 1st "Browse". Your Picture file should come up. Click on the small pic that you saved. Scroll down more to "Submit Reply". That should do it. If your pic was over 50KB the pic won't post. Then your pissed because you have to go back to the PhotoShop and reduce the pic some more. You're sure to screw up at 1st :hmm: But keep at it. Stuck? Ask another question and I'll try to help.

See why not many was quick to help? Takes some time. The other guy was talking about another method. It allows you to post more than one pic at a time. Since your only allowed 50KB you store your pics at another web site.
Since the pic is stored elsewhere and is linked to your post it doesn't eat up your 50KBs.

You may want to print the instructions. I think it helps you get through it easier. There are some other tricks but this is a good start.

Hey, We're looking for a pic of that Viper :rolleyes:

tzoid
07-30-04, 07:18 PM
OK, we'll see how well this old brain can follow your instructions...if I fail, don't think it was the teacher...you did a very thorough job of explaining!!

tzoid
07-30-04, 07:20 PM
RobertCTS....very good instructions!! Notice how I like black...neighbors think I'm a funeral director. Hope you like the picture.

RobertCTS
07-31-04, 06:55 AM
RobertCTS....very good instructions!! Notice how I like black...neighbors think I'm a funeral director. Hope you like the picture.

Tzoid,
Magnificient!! :bouncy:
What is the convertible in the center? Tailights look a bit like mercedes?

tzoid
07-31-04, 01:53 PM
'02 320SLK....wife's little bomb