Rx8 engine runs hot
#1
Rx8 engine runs hot
Ok i know that the rx8 engine runs hotter than most cars. i know there is advice on what to do about it but its scattered through threads so lets brain storm on how to fix the problem. i think the engine runs better and smoother when cooler. if there are any threads like this im sorry iguewss i didnt look hard enough
#2
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Unless your planning on making drastic changes in the airflow pattern of the car, there's not much you can do. As far as I know engine heat isnt an issue except for a select few who end up burning coil packs in certain situations.
#4
I use water wetter. I don't know how much it cools, but the temp guage is down several bars lower than normal. Given how much antifreeze is in my car, I'd guess somewhere around 10-15 degrees cooler.
#5
Originally Posted by the-jewish-rx8
well i dont know if this is a joke or not but someone sugested running the air intake into the cabin where it can suck in the air condionting
Seriously, if anyone want's to try this, I'd be interested in seeing how it turns out.
#6
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i can tell you how it will work....
take the intake box off, hold you hand near the TB, have a buddy floor it to redline. I dont think the AC flows that much air:D
take the intake box off, hold you hand near the TB, have a buddy floor it to redline. I dont think the AC flows that much air:D
#7
Originally Posted by the-jewish-rx8
Well, I don't know if this is a joke or not, but someone suggested running the air intake into the cabin where it can suck in the air (from the A/C).
#8
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Originally Posted by JasonHamilton
I use water wetter. I don't know how much it cools, but the temp guage is down several bars lower than normal. Given how much antifreeze is in my car, I'd guess somewhere around 10-15 degrees cooler.
#10
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Originally Posted by robertdot
HAHHAHAHA. That's funny. Maybe safer than a CAI. Too bad the AC sucks.
Seriously, if anyone want's to try this, I'd be interested in seeing how it turns out.
Seriously, if anyone want's to try this, I'd be interested in seeing how it turns out.
While it might help slightly reduce intake charge temps, the occupants would probably go deaf from the noise in the cabin. This was done several years back with a beater racing Miata while screwing around with CAI designs, and they said the noise was unbearable.
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Originally Posted by zzum-zum
What is water wetter?
it's a etergant substance which breaks the surface tension of the coolant (water) allowing a greater rate of heat exchange.
jewish-RX8, if you're worried about engine temps, you could try this and also try running less anti-freeze (basically straight water, for the summer, or if you're in a climate which never comes close to freezing even all year around), which will give you a higher heat capacity, allowing the coolant to stay cooler while radiating the same amount of heat.
#12
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It's hot, really? Yesterday when I did an oil check I found a frog literally cooked onto my front sway bar! It didn't all come off, and the bottom of it was blackened from the heat, and I have no idea how it got there.
My solution to keeping the engine cooler is to drive faster :p
My solution to keeping the engine cooler is to drive faster :p
#13
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Originally Posted by Rotarian_SC
.........My solution to keeping the engine cooler is to drive faster :p
rx8cited
#14
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Originally Posted by rx8cited
How do you do that in stop-n-go traffic ? Or do they not have that in SC? I just ordered a case of Water Wetter. .
rx8cited
rx8cited
#15
[QUOTE=wakeech]it's a etergant substance which breaks the surface tension of the coolant (water) allowing a greater rate of heat exchange.
jewish-RX8, if you're worried about engine temps, you could try this and also try running less anti-freeze (basically straight water, for the summer, or if you're in a climate which never comes close to freezing even all year around), which will give you a higher heat capacity, allowing the coolant to stay cooler while radiating the same amount of heat.[/QUOTE
thats not correct, less antifreeze means the water boils at a lower temp and becomes steam and then the cooling is dramatically decreased. I have my doubts about water wetter as well, but I haven't used it.
jewish-RX8, if you're worried about engine temps, you could try this and also try running less anti-freeze (basically straight water, for the summer, or if you're in a climate which never comes close to freezing even all year around), which will give you a higher heat capacity, allowing the coolant to stay cooler while radiating the same amount of heat.[/QUOTE
thats not correct, less antifreeze means the water boils at a lower temp and becomes steam and then the cooling is dramatically decreased. I have my doubts about water wetter as well, but I haven't used it.
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thats not correct, less antifreeze means the water boils at a lower temp and becomes steam and then the cooling is dramatically decreased. I have my doubts about water wetter as well, but I haven't used it.
#18
Your statement about more antifreeze being better at removing heat is incorrect.
The specific heat capacity for pure water is 1 Btu/lb/°F , whereas most ethylene & propylene glycols are around 0.6-0.8. Therefore, running pure water will remove more Btu's/hr for a given mass flow rate & result in a cooler engine. The primary reason for antifreeze is boiling point elevation and freezing point depression, along w/ increasing the lubricity of the coolant & improving seal & water pump bearing life. Most race engines run pure water w/ a lubricity enhancer & surface
tension reducer. This is why most manufacturers recommend a max 50:50 by volume mixture of af & h20,as anything greater will result in overheating.
[QUOTE=azben]
:D
The specific heat capacity for pure water is 1 Btu/lb/°F , whereas most ethylene & propylene glycols are around 0.6-0.8. Therefore, running pure water will remove more Btu's/hr for a given mass flow rate & result in a cooler engine. The primary reason for antifreeze is boiling point elevation and freezing point depression, along w/ increasing the lubricity of the coolant & improving seal & water pump bearing life. Most race engines run pure water w/ a lubricity enhancer & surface
tension reducer. This is why most manufacturers recommend a max 50:50 by volume mixture of af & h20,as anything greater will result in overheating.
[QUOTE=azben]
Originally Posted by wakeech
it's a etergant substance which breaks the surface tension of the coolant (water) allowing a greater rate of heat exchange.
jewish-RX8, if you're worried about engine temps, you could try this and also try running less anti-freeze (basically straight water, for the summer, or if you're in a climate which never comes close to freezing even all year around), which will give you a higher heat capacity, allowing the coolant to stay cooler while radiating the same amount of heat.[/QUOTE
thats not correct, less antifreeze means the water boils at a lower temp and becomes steam and then the cooling is dramatically decreased. I have my doubts about water wetter as well, but I haven't used it.
jewish-RX8, if you're worried about engine temps, you could try this and also try running less anti-freeze (basically straight water, for the summer, or if you're in a climate which never comes close to freezing even all year around), which will give you a higher heat capacity, allowing the coolant to stay cooler while radiating the same amount of heat.[/QUOTE
thats not correct, less antifreeze means the water boils at a lower temp and becomes steam and then the cooling is dramatically decreased. I have my doubts about water wetter as well, but I haven't used it.
#19
I stand by my statement...I never said glycol had a higher cooling rate than water. You make make an assumption of water being the cooling solution when in actuality it would be steam if the car was run for any period of time. Steam is not as efficient hence glycol is added.
#20
Antifreeze has poor cooling properties. 100% antifreeze will overheat
your engine. It is also more viscous. Water is the best coolant.
It has high heat capacity and good heat conductivity. Unfortunately,
it freezez at 0C or 32F. Water is very corrosive at higher temperature
to engines that have parts made out of different metals or alloys
(electrolysis).
It is best to use as little antifreeze as required for cold
protection in your area and manufacturers recommendations for
antifreeze's additives.
Mixing antifreeze and water reduces the freezing point and
increases the boiling point of the mixture. If you don't have
enough antifreeze in the mixture, you risk freezing the coolant
(and engine damage) in the winter, and boiling over in the summer.
Water has a very high specific heat capacity, so a given mass of
water can absorb more energy than straight antifreeze (for a given
temperature rise). So the antifreeze/water mix is a more
efficient coolant than antifreeze alone.
There are other cooling approaches, too. Some race engines have
used *pure water* for a coolant. To minimize water boiling and
pump cavitation, their cooling systems have very high relief
pressures (60-90 psi).
Also some engines are designed to run on pure propylene glycol.
The specific heat capacity is less than water, but the boiling
point is much higher (about 370 deg.F).
your engine. It is also more viscous. Water is the best coolant.
It has high heat capacity and good heat conductivity. Unfortunately,
it freezez at 0C or 32F. Water is very corrosive at higher temperature
to engines that have parts made out of different metals or alloys
(electrolysis).
It is best to use as little antifreeze as required for cold
protection in your area and manufacturers recommendations for
antifreeze's additives.
Mixing antifreeze and water reduces the freezing point and
increases the boiling point of the mixture. If you don't have
enough antifreeze in the mixture, you risk freezing the coolant
(and engine damage) in the winter, and boiling over in the summer.
Water has a very high specific heat capacity, so a given mass of
water can absorb more energy than straight antifreeze (for a given
temperature rise). So the antifreeze/water mix is a more
efficient coolant than antifreeze alone.
There are other cooling approaches, too. Some race engines have
used *pure water* for a coolant. To minimize water boiling and
pump cavitation, their cooling systems have very high relief
pressures (60-90 psi).
Also some engines are designed to run on pure propylene glycol.
The specific heat capacity is less than water, but the boiling
point is much higher (about 370 deg.F).
#22
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Originally Posted by azben
thats not correct, less antifreeze means the water boils at a lower temp and becomes steam and then the cooling is dramatically decreased. I have my doubts about water wetter as well, but I haven't used it.
no, seriously, because of the higher molar head capacity of water, it can move the same amount of heat at a lower tempurature, thus keeping your motor cooler, honest to goodness. i've also never heard of alcohol raising the boiling tempurature of water, as it doesn't desolve into water (it's not suspended in it, is what i mean) and has a point of evaporation obviously excessively lower than water does.
water wetter, or any other coolant additive in that vien works, really really well.
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going over the posts after that one, i don't know about the side effects of water wetter brand stuff and its side effects specifically, in either a Miata or RX-8 application, but i do know that they science behind it is very sound.
#24
Wrong again, sorry! Not trying to be an a$$ but I'm an automotive engineer & have been doing this stuff for a living for over 20 years & like to help people cut through the internet hype & actually learn something.
Anywho, the conversion of water into steam has a much higher heat transfer coefficient than liquid water & therefore would result in much lower engine temperatures,IF the system were designed to handle the high pressures & handle the moving & condensing of the steam back to liquid. A centrifugal pump does not pump gas (steam) very well. The system is pressurized to prevent the coolant from flashing to steam.
I am making the assumption that the coolant (water,whatever) is the cooling solution because it is. If you have any significant amount of steam in your existing cooling system, it will quickly overheat
Anywho, the conversion of water into steam has a much higher heat transfer coefficient than liquid water & therefore would result in much lower engine temperatures,IF the system were designed to handle the high pressures & handle the moving & condensing of the steam back to liquid. A centrifugal pump does not pump gas (steam) very well. The system is pressurized to prevent the coolant from flashing to steam.
I am making the assumption that the coolant (water,whatever) is the cooling solution because it is. If you have any significant amount of steam in your existing cooling system, it will quickly overheat
Originally Posted by azben
I stand by my statement...I never said glycol had a higher cooling rate than water. You make make an assumption of water being the cooling solution when in actuality it would be steam if the car was run for any period of time. Steam is not as efficient hence glycol is added.
#25
are you sure you aren't trying to be an a$$? read my statements and the others posted carefully ifastfd, misunderstanding on your part. I said cooling is decreased dramatically, and it would be if you only used water in your car (wakeech suggested putting water in the car so that is the premise my comments are based on) for the reasons you stated. The pump wouldn't cycle it well if at all, you would be a condenser/evap setup, etc.
my second statement said "would be steam if the car was run for any period of time. Steam is not as efficient hence glycol is added." Notice the context "if the car" preceding most of that statement.
my second statement said "would be steam if the car was run for any period of time. Steam is not as efficient hence glycol is added." Notice the context "if the car" preceding most of that statement.