T Stat Question

Hey folks! Dave is giving me his T-Stat from his old engine, which is a 180. I was wondering if it is ok to put in a 2005, if there was any changes or things of that nature. The T-Stat has been sitting in his garage since the engine swap, I just want to make sure everything would be ok. Thanks all.

As far as I know everything is the same...Go for it!

Do you have a predator yet? If not not really wont do no good, untill you have it.

Ya Ive had the predator, just been waiting for dave to bring the tstat to work.

Everything should work ok. You just have to make sure you change your fan settings with the predator or else your fans will run non stop and eventually burn the fan motors out.

OK, what EXACTLY will be the benefit of a 180 t-stat? I'm sure it's been mentioned somewhere here before, but just wondering. And will it do you any good if your engine is bone stock to this point, even with a Predator?

Signed,

Curious in LITH.

helps the engine run cooler...

Dartboy wrote:

helps the engine run cooler...

......yeahhhhhhhhhh.....which does what?

read


http://www.lxforums.com/board/showthread.php?t=33559

http://www.lxforums.com/board/showthread.php?t=95057



via Predator

Cooling Fans AC OFF
199.39 Deg - High MPH HS Fan On
199.39 Deg - High MPH MS Fan On
190.39 Deg - High MPH LS Fan On
199.39 Deg - Low MPH HS Fan On
199.39 Deg - Low MPH MS Fan On
190.39 Deg - Low MPH LS Fan On

Cooling Fans AC On
199.39 Deg - HS Fan On
199.39 Deg - MS Fan On
190.39 Deg - LS Fan On

i have not changed out my t-stat but i have altered my fan settings... car will not reach above 203 ever...

Motor wrote:

read


http://www.lxforums.com/board/showthread.php?t=33559

http://www.lxforums.com/board/showthread.php?t=95057



via Predator

Cooling Fans AC OFF
199.39 Deg - High MPH HS Fan On
199.39 Deg - High MPH MS Fan On
190.39 Deg - High MPH LS Fan On
199.39 Deg - Low MPH HS Fan On
199.39 Deg - Low MPH MS Fan On
190.39 Deg - Low MPH LS Fan On

Cooling Fans AC On
199.39 Deg - HS Fan On
199.39 Deg - MS Fan On
190.39 Deg - LS Fan On

OK, I read it. That just convinced me to stick with the stock t-stat. Or, didn't give me a strong case to go with a 180. Seems from the threads that running at a lower temp COULD cause increased engine wear, and switching to a 180 MIGHT give me a SLIGHT performance gain but it's debatable at best.

Iguanaman wrote:

OK, I read it. That just convinced me to stick with the stock t-stat. Or, didn't give me a strong case to go with a 180. Seems from the threads that running at a lower temp COULD cause increased engine wear, and switching to a 180 MIGHT give me a SLIGHT performance gain but it's debatable at best.

It really is useful since heat soak is our worst enemy...Running a cooler engine will give you better performance.I'm not saying it'll give you 30hp but it will perform better.As far as worrying about faster wear n tear,then you're better off not doing any mods at all.Any mod will increase wear n tear but if done correctly, it will not harm the engine.Our cars can take a whole lot of abuse.There built for it...

This may not be a popular answer, but this is what I have determined:

The speed density system that is incorporated in our cars is not like the cars from the past when it was carburetor, heads, cam, intake and cooling system. Timing and spark was the name of the game with a cool thermostat.

Today, the engine determines load before it ever goes to any other step.

Load = MAP div by barometric pressure = value X present RPM div by total possible rpm = a value.

This load value is then multiplied x Throttle position sensor x ENGINE COOLANT TEMPERATURE x intake air temperature x battery voltage x short term adaptives x O2 x long term adaptives = PULSE WIDTH or how long the injector is open.


If the engine through the ECT thinks it is still cold, it is going to add more fuel. Add the Predator, and you get more fuel. However more fuel doesn't equate to more power. Having a cold ECT is like driving around with the choke partially pulled. In some cases, it may give more power but use much more fuel, but virtually 90% of the time, it is going to be a hinderance.

Remember that LEAN is MEAN. Efficiency gets the power because the engine can translate the energy conversion. More fuel doesn't always = more power.

BTU from Potential energy to Kinetic energy is the ticket here!

Now, if you get a tune done by a professional that goes in and changes the parameter in the PCM so that 180 deg is the theshold of closed loop, then the 180 T stat would be fine. You just can't throw in a 180 t stat with a PCM that needs 203 for comfort etc.

Regards,
Brian
BND Automotive LLC
440-821-9040

From the earlier posts:

Many people have called me and have asked specific questions on the different types of fuel delivery systems and their different names. Many questions too about what does Mass Airflow mean, and what is speed density and what does that really mean.

I thought it would be a good time to educate a little bit on some of the principles of Speed Density and how it functions in our Chrysler designed cars.

Obviously we have to know about these systems to understand how to tune them, how they function, and of course what does ACES IV do in the mix.

Since we all know that our cars are computer controlled and that they measure the fuel to the engine, we just don't really understand how it is done.

Once you get past a carburetor, it becomes like a black art or something because we know we have fuel injectors and a pcm and it all functions when we turn the key and we say ok it works and thats about all I know.

For the average person, that is fine, but when you are involved in tuning your car with a Predator or other devices, it becomes important to understand what parameters the systems depend on.

Mass Air Flow is a system that uses exact measurement of air entering the engine as it's primary factor along with crankshaft position to determine the volume of fuel provided to the engine. So basically it monitors air flow and is relatively slow to react. Remember that airflow speeds up and slows down less rapidly than manifold pressure so the PCM control of the fuel supply is not as succinct as is a Speed Density System.

The second type of system is the Density Speed System that uses a MAP (Manifold Absolute Pressure) sensor which is the dominant input to the PCM. The inputs from the Camshaft Position Sensor and the Crankshaft Position Sensors are also required but in a less important capacity. This is a really old system that I do not believe anyone is still using at this time or any longer.

Speed Density Systems are what Chrysler uses and have used for many years on their cars. In a Speed Density System, the PCM uses the MAP sensor and the Crankshaft Position Sensor for determining fuel volume.

This way it monitors engine speed, monitors intake manifold pressure, responds much more rapidly and allows the PCM to closely monitor the engine operating conditions and the base fuel supply on that information. This is a much more accurate system.

Really the engine has to determine load by several factors to calcuate what it needs to know to meter the appropriate fuel.

Manifold Absolute Pressure divided by barometric pressure (baro read sensor)
times current RPM divided by Max potential RPM to determine that load.

So basically air density and speed of the vehicle.

Now, understanding how the PCM determines load, we have to incorporate the other inputs that are necessary for determining the injector pulse width.

This can be determined by this expression:

Load x TPS x ECT x IAT x BAT x LT x O2 x ST = Pulse Width.

TPS = Throttle Position Sensor - which provides information on the current mode of operation (idle, off-idle acceleration, etc.) and performs various operating strategies. When the TPS increases rapidly for example, the injector pulse width is greatly increased to deliver the amount of fuel required.

ECT = Engine Coolant Temperature which is the second biggest modifier of pulse width after the MAP. If the engine is cold, fuel will not atomize as easily (see summer vs winter fuel post) so the PCM will add extra fuel depending on the value from the ECT. This is where the ignition improver of the ACES IV works well to get the fuel molecularly balanced to atomize and ignite quicker in cold weather.

If the engine is hot, of course fuel volume will be altered accordingly. If your ECT signal is ever lost, the PCM will substitute a preset value and the limp in mode would be triggered.

IAT = Intake Air Temperature (also known as Charge Temperature Sensor from years ago). If the ECT shows High and the IAT shows cold (dense air) then the PCM will add extra fuel. If the air is hot (thin) then the spark advance is adjusted accordingly.

If the IAT signal is lost, the PCM will substitute a value based on the battery signal and the Ambient Temperature Sensor.

BAT = Sensed Battery Voltage. Remember that injectors are rated for specific flow at specific voltages. If battery voltage is lower than the injector rating, it will take longer for the injector to open and it may not open as far, so the PCM needs to know the voltage to compensate by changing the pulse width. In some vehicles the IAT and BT are combined and called the Inlet Air Temperature Sensor.

LT = Short Term and Long Term Adaptives - the short term adaptive memories allow the PCM to do two things. First it gives it the capability to change injector pulse width to bring the O2 Sensor to its midrange of operation. Second, it allows for storage of corrections required for specific operating conditions (long term). This is what starts to change due to the changes in fuels at the refinery. Changes occur in the energy content and allow the adaptives to change. ACES IV tends to help bridge the gap between the highs and lows by smoothing energy release.

O2= Oxygen Sensors. The PCM looks at the O2 signal to determine how well it did on the BASE pulse width calculation. The data provided by the O2 Sensor signal tells the PCM how much oxygen was left over after the combustion process. Adaptations are withheld until closed loop conditions exist.

ST= Short Term and Long Term Adaptives - the short term adaptive memories allow the PCM to do two things. First it gives it the capability to change injector pulse width to bring the O2 Sensor to its midrange of operation. Second, it allows for storage of corrections required for specific operating conditions (long term). This is what starts to change due to the changes in fuels at the refinery. Changes occur in the energy content and allow the adaptives to change. ACES IV tends to help bridge the gap between the highs and lows by smoothing energy release.

With all the defined inputs being provided, the PCM provides the determined pulse width (the time the injector is open spraying fuel) control to energize the fuel injectors. As the PCM increases or decreases this pulse width, the amount of fuel released into the combustion process is increased and or decreased.

Many discussions I have had with customers is getting the air/fuel ratio as close to Stoichiometric.

This is the ideal result to keep the amount of fuel injected into the engine as reasonably close to the value of 14.7 parts of air to 1 part of fuel. Also expressed as 14.7 to 1. This ratio results in the best engine performance, the highest fuel economy, and the least emissions (lightest black in the exhaust tips/pipes etc.)

By the way, when the engine is cold, it is in what is called open loop. This is when there is no O2 sensor information used, predetermined base fuel calculations are used and the O2 sensors are not adapted at all.

As the engine warms up, then it goes to closed loop. Now O2 sensor information is utilized by the PCM to alter the base fuel calculations.

The sooner that your car reaches closed loop operation the better the fuel economy and power is achieved without excessive washdown creating acids etc.

Hopefully this will help many understand the basics of what a Speed Density System is and how it functions, how it compares to a Mass Airflow System and a Density Speed System.

When you can understand how this works, it gives you a better grasp of why ACES IV can produce more power with less fuel as the utilization of fuel energy is transferred from potential to kinetic energy.

Regards,
Brian
BND Automotive LLC
440-821-9040

Damn Brian thanks so much for this explanation...

Wow Brian (the smart one...) thanks for all that!!

irishrt5.7 wrote:

Damn Brian thanks so much for this explanation...

You are welcome! The more you know about how your car works, the better decisions you can make about what really does contribute to more power and performance, and what is designed to give you a lighter wallet! LOL. I don't think anyone on this forum or any other minds spending money when it does make it better for our cars etc.

Regards,
Brian
BND Automotive LLC
440-821-9040

370 Hemi wrote:

irishrt5.7 wrote:

Damn Brian thanks so much for this explanation...

You are welcome! The more you know about how your car works, the better decisions you can make about what really does contribute to more power and performance, and what is designed to give you a lighter wallet! LOL. I don't think anyone on this forum or any other minds spending money when it does make it better for our cars etc.

Regards,
Brian
BND Automotive LLC
440-821-9040

whats your verdict

that unless i am told that i need to get one i will be staying w/ my stocker...

Wow is right......that's a whole lotta info to digest. I thought I wanted one because so many said they had 'em but looks like I'll be sticking with the stock T stat.

Thanks for all the great info

370 Hemi wrote:

This may not be a popular answer, but this is what I have determined:

The speed density system that is incorporated in our cars is not like the cars from the past when it was carburetor, heads, cam, intake and cooling system. Timing and spark was the name of the game with a cool thermostat.

Today, the engine determines load before it ever goes to any other step.

Load = MAP div by barometric pressure = value X present RPM div by total possible rpm = a value.

This load value is then multiplied x Throttle position sensor x ENGINE COOLANT TEMPERATURE x intake air temperature x battery voltage x short term adaptives x O2 x long term adaptives = PULSE WIDTH or how long the injector is open.


If the engine through the ECT thinks it is still cold, it is going to add more fuel. Add the Predator, and you get more fuel. However more fuel doesn't equate to more power. Having a cold ECT is like driving around with the choke partially pulled. In some cases, it may give more power but use much more fuel, but virtually 90% of the time, it is going to be a hinderance.

Remember that LEAN is MEAN. Efficiency gets the power because the engine can translate the energy conversion. More fuel doesn't always = more power.

BTU from Potential energy to Kinetic energy is the ticket here!

Now, if you get a tune done by a professional that goes in and changes the parameter in the PCM so that 180 deg is the theshold of closed loop, then the 180 T stat would be fine. You just can't throw in a 180 t stat with a PCM that needs 203 for comfort etc.

Regards,
Brian
BND Automotive LLC
440-821-9040

From the earlier posts:

Many people have called me and have asked specific questions on the different types of fuel delivery systems and their different names. Many questions too about what does Mass Airflow mean, and what is speed density and what does that really mean.

I thought it would be a good time to educate a little bit on some of the principles of Speed Density and how it functions in our Chrysler designed cars.

Obviously we have to know about these systems to understand how to tune them, how they function, and of course what does ACES IV do in the mix.

Since we all know that our cars are computer controlled and that they measure the fuel to the engine, we just don't really understand how it is done.

Once you get past a carburetor, it becomes like a black art or something because we know we have fuel injectors and a pcm and it all functions when we turn the key and we say ok it works and thats about all I know.

For the average person, that is fine, but when you are involved in tuning your car with a Predator or other devices, it becomes important to understand what parameters the systems depend on.

Mass Air Flow is a system that uses exact measurement of air entering the engine as it's primary factor along with crankshaft position to determine the volume of fuel provided to the engine. So basically it monitors air flow and is relatively slow to react. Remember that airflow speeds up and slows down less rapidly than manifold pressure so the PCM control of the fuel supply is not as succinct as is a Speed Density System.

The second type of system is the Density Speed System that uses a MAP (Manifold Absolute Pressure) sensor which is the dominant input to the PCM. The inputs from the Camshaft Position Sensor and the Crankshaft Position Sensors are also required but in a less important capacity. This is a really old system that I do not believe anyone is still using at this time or any longer.

Speed Density Systems are what Chrysler uses and have used for many years on their cars. In a Speed Density System, the PCM uses the MAP sensor and the Crankshaft Position Sensor for determining fuel volume.

This way it monitors engine speed, monitors intake manifold pressure, responds much more rapidly and allows the PCM to closely monitor the engine operating conditions and the base fuel supply on that information. This is a much more accurate system.

Really the engine has to determine load by several factors to calcuate what it needs to know to meter the appropriate fuel.

Manifold Absolute Pressure divided by barometric pressure (baro read sensor)
times current RPM divided by Max potential RPM to determine that load.

So basically air density and speed of the vehicle.

Now, understanding how the PCM determines load, we have to incorporate the other inputs that are necessary for determining the injector pulse width.

This can be determined by this expression:

Load x TPS x ECT x IAT x BAT x LT x O2 x ST = Pulse Width.

TPS = Throttle Position Sensor - which provides information on the current mode of operation (idle, off-idle acceleration, etc.) and performs various operating strategies. When the TPS increases rapidly for example, the injector pulse width is greatly increased to deliver the amount of fuel required.

ECT = Engine Coolant Temperature which is the second biggest modifier of pulse width after the MAP. If the engine is cold, fuel will not atomize as easily (see summer vs winter fuel post) so the PCM will add extra fuel depending on the value from the ECT. This is where the ignition improver of the ACES IV works well to get the fuel molecularly balanced to atomize and ignite quicker in cold weather.

If the engine is hot, of course fuel volume will be altered accordingly. If your ECT signal is ever lost, the PCM will substitute a preset value and the limp in mode would be triggered.

IAT = Intake Air Temperature (also known as Charge Temperature Sensor from years ago). If the ECT shows High and the IAT shows cold (dense air) then the PCM will add extra fuel. If the air is hot (thin) then the spark advance is adjusted accordingly.

If the IAT signal is lost, the PCM will substitute a value based on the battery signal and the Ambient Temperature Sensor.

BAT = Sensed Battery Voltage. Remember that injectors are rated for specific flow at specific voltages. If battery voltage is lower than the injector rating, it will take longer for the injector to open and it may not open as far, so the PCM needs to know the voltage to compensate by changing the pulse width. In some vehicles the IAT and BT are combined and called the Inlet Air Temperature Sensor.

LT = Short Term and Long Term Adaptives - the short term adaptive memories allow the PCM to do two things. First it gives it the capability to change injector pulse width to bring the O2 Sensor to its midrange of operation. Second, it allows for storage of corrections required for specific operating conditions (long term). This is what starts to change due to the changes in fuels at the refinery. Changes occur in the energy content and allow the adaptives to change. ACES IV tends to help bridge the gap between the highs and lows by smoothing energy release.

O2= Oxygen Sensors. The PCM looks at the O2 signal to determine how well it did on the BASE pulse width calculation. The data provided by the O2 Sensor signal tells the PCM how much oxygen was left over after the combustion process. Adaptations are withheld until closed loop conditions exist.

ST= Short Term and Long Term Adaptives - the short term adaptive memories allow the PCM to do two things. First it gives it the capability to change injector pulse width to bring the O2 Sensor to its midrange of operation. Second, it allows for storage of corrections required for specific operating conditions (long term). This is what starts to change due to the changes in fuels at the refinery. Changes occur in the energy content and allow the adaptives to change. ACES IV tends to help bridge the gap between the highs and lows by smoothing energy release.

With all the defined inputs being provided, the PCM provides the determined pulse width (the time the injector is open spraying fuel) control to energize the fuel injectors. As the PCM increases or decreases this pulse width, the amount of fuel released into the combustion process is increased and or decreased.

Many discussions I have had with customers is getting the air/fuel ratio as close to Stoichiometric.

This is the ideal result to keep the amount of fuel injected into the engine as reasonably close to the value of 14.7 parts of air to 1 part of fuel. Also expressed as 14.7 to 1. This ratio results in the best engine performance, the highest fuel economy, and the least emissions (lightest black in the exhaust tips/pipes etc.)

By the way, when the engine is cold, it is in what is called open loop. This is when there is no O2 sensor information used, predetermined base fuel calculations are used and the O2 sensors are not adapted at all.

As the engine warms up, then it goes to closed loop. Now O2 sensor information is utilized by the PCM to alter the base fuel calculations.

The sooner that your car reaches closed loop operation the better the fuel economy and power is achieved without excessive washdown creating acids etc.

Hopefully this will help many understand the basics of what a Speed Density System is and how it functions, how it compares to a Mass Airflow System and a Density Speed System.

When you can understand how this works, it gives you a better grasp of why ACES IV can produce more power with less fuel as the utilization of fuel energy is transferred from potential to kinetic energy.

Regards,
Brian
BND Automotive LLC
440-821-9040

note that none of this has anything to do with heat soak in the motor. you are only talking about computer determining proper fuel tables. you are right saying that it doesn't matter which temp thermo is in there since the computer will determine what to do anyway unlike carbed motors. but you are missing the point of keeping the engine cooler as a whole.

if you ignore the gains by avoiding heat soak with a 180 thermo you are effectively saying heatsoak is not a problem. wich is 100% wrong on our large v8 motors. it has been proven to make almost half a second difference in track times between a cool car and one running at temp with a stock thermostat. that is the reason your car feels like a dog on hot summer days in traffic.

i will be sticking with my 180 thermo thank you...

ok now are you talking about the 5.7 or the 6.1 because the 5.7 doesnt see as much heat soak as the 6.1 does...

Normal Situations and mild runs around the city, I'd take stock therm with predator. But if I was running track or strip I'd do 180 but ya know to avoid the whole situation I'd go 180 as cheap insurance....

irishrt5.7 wrote:

ok now are you talking about the 5.7 or the 6.1 because the 5.7 doesnt see as much heat soak as the 6.7 does...

both. even 3.5's and 2.7's

its not about just our cars or motor options. most cars benifit from a thermo change. look on almost all car forums and people are dropping thermo temps. the only reason factory's put high thermos in is because of emissions reasons. i have had a 180 thermo in my truck for over 8 years. and it has nothing to do with if a car is computer controlled or carbed. its about keeping the engine cool and fuel issues are secondary to that. its actually better to do in computer controlled cars because of their self sufficient fuel management systems.

john now what do you run constant temps do you think in your cars???

like what is my gauge at?

my car with the stock thermo ran a constant 205 in the summer and 220 was not uncommon in traffic. now it sits at 185ish and never gets over 200 even in summer traffic.

before the thermo change it used to feel like i was loosing power in the summer traffic since the motor will cut timing when it is getting heat soak to avoid detonation problems. since the switch i have seen no negative effects in gas mileage, but i had more power in traffic due to the motor being more efficient.

the truck ran at 195 stock all the time and now it sits at 180 all the time.