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all of these posts about aquamist and water wetter...got me thinking...<p>i used to have a Miata...a 1990...so this is a much older car, much less was as computerized..but on that car, most guys who modded them swapped out the thermostat to a slightly cooler one and advanced the timing.....<p>on the R - is it possible to put in a cooler thermostat and force the car to keep the motor cooler...and thus maybe stop some of the power loss in the heat...or is that not possible on our cars? <p>
 

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Sure it is physically possible as you know, however, we really would need someone who knows the ECU and how it would react to a -10 to -20 degree difference in coolant temps... Like I said in the WW thread, the ECU may freak out unless it was tuned for it... hint hint IPD <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/smile.gif" BORDER="0">
 

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Re: Cooler Thermostat (23109VC)

Wouldn't the cooler thermostat just open up earlier making the engine take a little longer to reach operating temperature. And once at operating temperature, isn't the thermostat pretty much wide open?
 

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Re: Cooler Thermostat (steamboatsig)

Not neccessarily.....in my Avalanche the stock thermo. would get the engine temp. up to 220F....I swapped it out b/c the computer tuning called for a "low temp therm." so I put in a 160F and the temp holds strong at around 180F all day long......even with a low temp therm. the listed value is what it opens at, and doesn't mean that's what temp your car will be running at.
 

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Re: Cooler Thermostat (23109VC)

Better off with an oil cooler but a lower temp thermostat and a lower temp fan switch by 10-20 degrees F probably would not hurt <p>In the winter and even fall and cooler weathers use the normal
 

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Re: Cooler Thermostat (23109VC)

The heat-related power loss is because of air temp, not water. But, changing to a colder thermostat is very likely to make the car run worse, IMO. In olden times, it was common to switch to one in the summer, because the fans were driven off the water pump pulley, and cars would overheat easily at idle. Also, they didn't need the higher temps to run properly. In winter, you'd switch to have your heat back.<p>The only thing I can imagine would help the R is that with colder water, the intercooler behind the R's radiator would get a little less heatsoak. But, we're not talking like it's getting cold air. I doubt it would make a bit of difference.<p>Tom.
 

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Re: Cooler Thermostat (tmtalpey)

If you want to test it, you could try running with no thermostat or drill some holes in it to let coolant flow even when it's close. Using tricks like this from the old days will likely throw some codes (ie ECU freak out as the other guys have said).<p>Test it and let us know <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/biggrin.gif" BORDER="0"> <p>ps. Make sure you track ECT and post some graphs.<p>LTA<br>
 

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Re: Cooler Thermostat (tmtalpey)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>tmtalpey</b> »</i></TD></TR><TR><TD CLASS="quote">...The only thing I can imagine would help the R is that with colder water, the intercooler behind the R's radiator would get a little less heatsoak...Tom.</TD></TR></TABLE><p>Wouldn't a cooler thermostat have to run the radiator HOTTER to remove more heat from the engine? <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/confused.gif" BORDER="0"> <br>
 

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Re: Cooler Thermostat (ljjones)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>ljjones</b> »</i></TD></TR><TR><TD CLASS="quote">Wouldn't a cooler thermostat have to run the radiator HOTTER to remove more heat from the engine? <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/confused.gif" BORDER="0"> </TD></TR></TABLE><br>No. I bet the stock thermostat is a 192 degree unit, maybe a bit higher... all a thermostat does is open at a set temperature. Once coolant in the ENGINE reaches that set temp, it opens and allows the coolant to circulate through the radiator. So if you put say a 180 degree thermostat in there it will open up 12 degrees cooler than the 192 degree unit theoritically keeping the coolant temp 12 degrees cooler.
 

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Re: Cooler Thermostat (nikhsub1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>nikhsub1</b> »</i></TD></TR><TR><TD CLASS="quote"><br>No. I bet the stock thermostat is a 192 degree unit, maybe a bit higher... all a thermostat does is open at a set temperature. Once coolant in the ENGINE reaches that set temp, it opens and allows the coolant to circulate through the radiator. So if you put say a 180 degree thermostat in there it will open up 12 degrees cooler than the 192 degree unit theoritically keeping the coolant temp 12 degrees cooler.</TD></TR></TABLE><p>And don't you have to continue dumping more heat from the radiator to keep the block temperature from rising any further? What would you do if you wanted to raise the block temp back to 192 again? Bypass a little more coolant around the radiator so it dumps a little less heat to the air. No?<br> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/embeer.gif" BORDER="0"> <br>
 

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Re: Cooler Thermostat (ljjones)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>ljjones</b> »</i></TD></TR><TR><TD CLASS="quote">And don't you have to continue dumping more heat from the radiator to keep the block temperature from rising any further? What would you do if you wanted to raise the block temp back to 192 again? Bypass a little more coolant around the radiator so it dumps a little less heat to the air. No?<br> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/embeer.gif" BORDER="0"> </TD></TR></TABLE><br>I don't really understand what you want to know??? Rad temp is not important really, they are efficient. Everything stays cooler with a cooler termo, rad included. To get back to the higher temp if you swapped thermo's, you'd have to put the original thermo back in.
 

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Re: Cooler Thermostat (nikhsub1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>nikhsub1</b> »</i></TD></TR><TR><TD CLASS="quote">...To get back to the higher temp if you swapped thermo's, you'd have to put the original thermo back in.</TD></TR></TABLE><p>Just a "thought experiment" concerning tmtalpey's assumption of less heat transfer from radiator to intercooler with a cooler thermostat.<br>The thermostat regulates block temperature by regulating coolant flow volume through the radiator.<br>Assuming everything else is constant (<I>ie</I> ambient air temp, power delivered, engine efficiency - and therefore waste heat, etc.), to get a cooler block temperature more heat must be transferred to the air by INCREASING coolant flow volume in the rad. The thermostat "opens wider" to regulate the block to the lower temperature. More waste heat flows into the air because the air-to-radiator temperature differential is increased by the elevated radiator temperature. The block runs cooler because more of the waste heat is being transferred to the airstream. If the intercooler sits in this same airstream, downwind of the radiator...<p>Also, I'll bet the engine runs at maximum thermal efficiency at the design temperature of 192-195. Lower efficiency at the lower block temp would mean even more waste heat dumped into the radiator/intercooler combo.<p> <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/embeer.gif" BORDER="0"> + <IMG NAME="icon" SRC="http://********************/smile/emcocktl.gif" BORDER="0"> <p>
 

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lj, I think you are confused... a lower thermostat will keep the rad cooler as well... it allows the coolant to enter the rad at a lower temp, how does this translate into 'waste heat'. The IC and radiator have nothing to do with each other except for their location, the IC is an air - air unit...
 

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Re: Cooler Thermostat (ljjones)

Bingo (in reference to ljjones' post)<p><br>It's simply a heat pump. If the intent is to have the engine run cooler, then <B>more</B> heat must be transferred away from the engine (via increased coolant volume). And, where is that heat going? To the radiator. So, the radiator must dissipate more heat.<p>However...<br>That doesn't necessarily mean that the coolant will be significantly hotter. Remember, the temperature guage in the dash is measuring water temperature, too. Will you see it "move" up? At maximum efficiency (some RPM sweet spot), the system can transfer good volumes of heat with very little measurable changes in water temperature (to those of us looking at a analog guage). But, at idle after a hard run, it can be difficult to remove that heat quickly and very likely the thermostat is wide open at this point.<p>It's also at this point the radiator's efficiency comes into play. How well the engine can remain cool depends on how well or how quickly the radiator dissipates the heat. In this case, it's the volume of air moving through it. If there is little volume of air for heat transfer, then there will be heat-soak and that will affect the nearby components (intercooler).<p>(Well, that turned out more wordy and lengthy that I expected. <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/sly.gif" BORDER="0"> )<p><br><TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>nikhsub1</b> »</i></TD></TR><TR><TD CLASS="quote">lj, I think you are confused... a lower thermostat will keep the rad cooler as well... it allows the coolant to enter the rad at a lower temp, how does this translate into 'waste heat'. The IC and radiator have nothing to do with each other except for their location, the IC is an air - air unit...</TD></TR></TABLE><p>nikhsub1, I can see how you feel the water temperature is cooler. Because the thermostat is opening sooner and keeping the coolant cooler.<br>However, keep in mind that the <B>engine is producing the same amount of heat as before!</B> The fuel combustion is the same temperature, the engine load and demands are the same. So, where is this heat going? The thermostat doesn't magically make the engine run cooler. <I>It allows more heat to be transferred away from the engine so that the water temperature is cooler.</I> The extra heat ends up at the radiator.<p><br>regards,<br>MAJ
 

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Re: Cooler Thermostat (digital_dreamer)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>digital_dreamer</b> »</i></TD></TR><TR><TD CLASS="quote">Bingo (in reference to ljjones' post)<p><br>It's simply a heat pump. If the intent is to have the engine run cooler, then <B>more</B> heat must be transferred away from the engine (via increased coolant volume). And, where is that heat going? To the radiator. So, the radiator must dissipate more heat.<p>However...<br>That doesn't necessarily mean that the coolant will be significantly hotter. Remember, the temperature guage in the dash is measuring water temperature, too. Will you see it "move" up? At maximum efficiency (some RPM sweet spot), the system can transfer good volumes of heat with very little measurable changes in water temperature (to those of us looking at a analog guage). But, at idle after a hard run, it can be difficult to remove that heat quickly and very likely the thermostat is wide open at this point.<p>It's also at this point the radiator's efficiency comes into play. How well the engine can remain cool depends on how well or how quickly the radiator dissipates the heat. In this case, it's the volume of air moving through it. If there is little volume of air for heat transfer, then there will be heat-soak and that will affect the nearby components (intercooler).<p>(Well, that turned out more wordy and lengthy that I expected. <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/sly.gif" BORDER="0"> )<p><br>nikhsub1, I can see how you feel the water temperature is cooler. Because the thermostat is opening sooner and keeping the coolant cooler.<br>However, keep in mind that the <B>engine is producing the same amount of heat as before!</B> The fuel combustion is the same temperature, the engine load and demands are the same. So, where is this heat going? The thermostat doesn't magically make the engine run cooler. <I>It allows more heat to be transferred away from the engine so that the water temperature is cooler.</I> The extra heat ends up at the radiator.<p><br>regards,<br>MAJ</TD></TR></TABLE><br>MAJ, please tell me how is it possible for the same radiator to be HOTTER when cooling 180 degree coolant versus 192 degree coolant. I never made mention about the engine's heat production changing, it won't. However, if water if permitted to enter the radiator at a COOLER temp, the rad certainly will NOT make more heat. Radiators are most efficient the greater the delta between air and water temp (deltaT). This obviously means that the rad will be more efficient the hotter the water is AND IT WILL REMOVE THE MOST HEAT the higher delta T is... so a higher temp thermostat will theoretically have the rad remove more heat from the water which goes back to my point that if anything, the rad will give off LESS heat with a lower temp thermostat.<p>In a traffic jam or high ambient temp stop and go driving the lower thermostat is likely to make little difference. However, at constant speed (highway, track etc) the water temp difference is real. Yes the engine is still making the same amount of heat but the rad is allowed to START cooling the water sooner (lower temp).
 

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Re: Cooler Thermostat (digital_dreamer)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>digital_dreamer</b> »</i></TD></TR><TR><TD CLASS="quote"> The thermostat doesn't magically make the engine run cooler. <I>It allows more heat to be transferred away from the engine so that the water temperature is cooler.</I> The extra heat ends up at the radiator.<br></TD></TR></TABLE><br>Sorry for double posting but this is just plain WRONG. The extra heat ultimately ends up in the air out of the radiator, not IN the radiator... That air will be cooler with a lower degree thermostat, period end of story.
 

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Re: Cooler Thermostat (ljjones)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>ljjones</b> »</i></TD></TR><TR><TD CLASS="quote">Just a "thought experiment" ... </TD></TR></TABLE><br>I don't get how you conclude that cooler water leaving the block results in higher temperatures in the radiator. The radiator doesn't store any energy and will be at about the same temp as the water inside it.<p>Tom.
 

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Re: Cooler Thermostat (tmtalpey)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>tmtalpey</b> »</i></TD></TR><TR><TD CLASS="quote"><br>I don't get how you conclude that cooler water leaving the block results in higher temperatures in the radiator. The radiator doesn't store any energy and will be at about the same temp as the water inside it.</TD></TR></TABLE><p>I guess the key to this whole thing is that only PART of the coolant passes through the radiator (the rest just recirculates in the block). Cooler block temp means MORE coolant through the radiator.<p>The radiator is ALWAYS cooler than the block but hotter than the air. How much hotter than the air? Enough hotter as is necessary to keep the block cooled to the thermostat set point temperature. If you need lower block temperature, you must raise the radiator temperature high enough to cool the block more (by heating the air more).<p>The thermostat just controls the ratio of radiator vs recirculated coolant flow.<p>2 more <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/embeer.gif" BORDER="0"> <br>
 

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Re: Cooler Thermostat (ljjones)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>ljjones</b> »</i></TD></TR><TR><TD CLASS="quote">I guess the key to this whole thing is that only PART of the coolant passes through the radiator (the rest just recirculates in the block). Cooler block temp means MORE coolant through the radiator.<p>The radiator is ALWAYS cooler than the block but hotter than the air. How much hotter than the air? Enough hotter as is necessary to keep the block cooled to the thermostat set point temperature. If you need lower block temperature, you must raise the radiator temperature high enough to cool the block more (by heating the air more).<p>The thermostat just controls the ratio of radiator vs recirculated coolant flow.<p>2 more <IMG NAME="icon" SRC="http://www.vwvortex.com/vwbb/embeer.gif" BORDER="0"> </TD></TR></TABLE><br>OK, I am done with this thread... lj you are very confused and don't have a grasp of this at all ...
 
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