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Topfun, airflow over water will reduce water temperature to subambient levels with the trade off of water evaporation, increased localized humidity. It's the obeys the same radiant heat transfer principles as a standard heat exchanger: the finer the droplet size, the more surface area, and the more airflow, the more cooling potential.

Evaporative water chillers work and are used in power plants for steam condensation loops. But in this application it's basically the same exact thing as an intercooler mister.

Would the size and complexity of a system be enough to offset 2-3 degree subambient water temperature, though?
 

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I run an A/W with ambient water and a heat exchanger with fan. A couple times when I had forgotten to turn the pump on the car ran exactly the same to almost the 1/8th then it nosed over once the water in the core got too hot. I've always wondered if it was mostly heating the water that was in direct contact with the internal passages and if circulating the water just in the core might have a different result?
 

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Topfun, airflow over water will reduce water temperature to subambient levels with the trade off of water evaporation, increased localized humidity. It's the obeys the same radiant heat transfer principles as a standard heat exchanger: the finer the droplet size, the more surface area, and the more airflow, the more cooling potential.

Evaporative water chillers work and are used in power plants for steam condensation loops. But in this application it's basically the same exact thing as an intercooler mister.

Would the size and complexity of a system be enough to offset 2-3 degree subambient water temperature, though?
I believe you're describing an OPEN system that is not a realistic option for this application. I worked at a power plant for 10 years and have worked as an HVAC Engineer for a few decades.
 

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I believe you're describing an OPEN system that is not a realistic option for this application. I worked at a power plant for 10 years and have worked as an HVAC Engineer for a few decades.
Yeah that's exactly what I'm describing (and for the record think it's a silly idea) You would have to have an open element evaporative heat exchanger, cooling water in a secondary loop to chill the intercooler loop. A ton of extra parts to run your a2w loop 2 degrees below ambient. And no gain over just spraying the water directly on an an a2a heat exchanger.
 

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Not a pressurized system?

Basic physics - without vaporization you will have no sub-cooling and you can't have something vaporize without expanding. If it's a closed system when it expands it creates pressure. What you're describing sounds like another form of perpetual motion and is not realistic.
Ever heard of a swamp cooler?
 

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What if you are spraying something other than water in the system? Say methanol? I know a guy that was the secondary injection engineer on an Indy car team. He said he could get the inlet air temp down to like 30 or 40f below ambient with methanol. Turbo with no intercooler
 

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Is this any different than how an air to air acts in an 1/8th mile car?
1500hp fwiw. Runs 5.ohhh's now, non intercooled on gas
Is this a 4500lb toboggan like boostedbowtie?
Like the one guy said, run methanol and put your hot rod on a diet.
 

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Discussion Starter #49
Is this a 4500lb toboggan like boostedbowtie?
Like the one guy said, run methanol and put your hot rod on a diet.
It's only 3450, but not dialed in yet. Still working on chassis to get the 60, and 330 in line with the 140 trap.
Eventually I would love to go to methanol fuel, but it's not in the cards right now, adding an A/w will have to do in the short term.
It seems as though the A/W without following water, can function reasonably well, as long as I cool it down between runs.
 

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Well the way I'm seeing this argument, it's half a dozen one way or six the other..

You take an air to water intercooler.. Pack it's reservoir full of ice.. Then make a long enough pull.. And you will be able to boil an egg with the hot water left in the reservoir..

Now take a well sized air to air, that's getting good air flow.. And you can do a full boost pull from coast to coast, and the turbo will never send 300 degree air to the motor.. It will be cooled hundreds of degrees before it leaves the intercooler..

I'm not saying an air to air is more efficient than a air to water in a drag racing environment.. My argument is that it is not the useless "heatsink" that it's being made out to be.. I like an air to air because it's so trouble free.. I see guys with air to water setups, that spend as much money on ice as the do race gas.. They have these big coolers like you use when you go deer hunting... Full of bags and bags and bags of ice.. And if they happen to go some rounds, they might be looking to buy some more..

Turbo II has a point with his advocacy of methanol .. But meth has it's own issues too.. Ones that I don't want to deal with on a regular basis.. Hell, I use to buy C16 by the drum.. Now days I'll pay extra for 10 five gallon cans.. Just so I don't have to wrassle with a heavy drum of fuel..

And now in Alex defense.. I'm going to guess that my man is a big time drinker.. Cause when some folks get "oiled up" they become someone different than they normally are.. Don't believe me?? Then watch some of those "Cops" and "LivePD" shows that are on the tube.. And you will see how obnoxious some of those folks can be when drunk.. Men and Women,,
Every car in my shop has an air to air. I do not hate air to air intercoolers or belittle them in anyway lets be clear. However I know very well how they act and what they do- hence why I can say with certainty they act as a heat sink. The air to water has a mechanical advantage with the water being a multiplier in the ability heat extraction of said heat sink. It's all the same but different haha. You can't have a head start or ice an air to air easily. That's why people think the air to water is better, you can cheat which will have effects on the rise over the run. I have a 3500hp dyno in house and am a nerd. I put sensors all over just for fun because we can. It's thermodynamics and I didn't make the rules. Now another topic we can get into is the response time on a GM IAT Sensor. LOL That would be a fun one with some of the guys in here.
 

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Thermal transfer rate is based on several factors - the difference in temperatures, the rate the heat is absorbed, rejected and time for this to occur. Given time, a temperature gradient from the hottest temp to the coolest temp peaks out and the heat transfer rate becomes steady state. For the fins to start rejecting a lot of heat, the intercooler body has to heat up first and that takes time. Imagine you pour boiling water into an aluminum pot. You could hold your hand against the outside of the pot for several seconds before it would be too hot to keep your hand there. And that's water which conducts heat/energy very fast against the aluminum surface, much faster than air.

For the short duration of a pass at the dragstrip (<10 seconds) the heat is being absorbed by the intercooler body material. The BTUs being absorbed from the mass of hot air are easily absorbed by the aluminum mass of the intercooler while rejecting very little of that heat (BTSs) via air flowing past the fins. After the run the fins become important to allow the intercooler body to cool back down closer to ambient to be ready for the next pass. If the car was run for an extended time then yes, the air flow past the fins become a factor to keep the IATs lower by rejecting the heat the intercooler body absorbs. Eventually you will reach a steady state where the fins are rejecting heat to keep the intercooler itself from getting so hot it stops being effective.

I'll bet if you cover the fins during a run your delta T (ending temp vs. your initial temp) will not be much different than with the fins exposed. After the run the intercooler will remain hot much longer though.
Good post. I got pretty busy here at the shop and forgot about this thread haha.
Once you have a good basis of thermodynamics it makes the concepts much easier to grasp.
 

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Every car in my shop has an air to air. I do not hate air to air intercoolers or belittle them in anyway lets be clear. However I know very well how they act and what they do- hence why I can say with certainty they act as a heat sink. The air to water has a mechanical advantage with the water being a multiplier in the ability heat extraction of said heat sink. It's all the same but different haha. You can't have a head start or ice an air to air easily. That's why people think the air to water is better, you can cheat which will have effects on the rise over the run. I have a 3500hp dyno in house and am a nerd. I put sensors all over just for fun because we can. It's thermodynamics and I didn't make the rules. Now another topic we can get into is the response time on a GM IAT Sensor. LOL That would be a fun one with some of the guys in here.

Either I'm one of the smartest people in the world.. OR.. I'm a complete dimwitted dipshit, that can't grasp the concept of how an air to air intercooler is just a heat sink..

You have all these thermodynamic engineers, all these highly experienced multiple air to air users, all these guys that are sooo sure they know exactly what they are talking about.. All of them are saying that an air to air intercooler is only a heat sink.. And that once it becomes "heat saturated", it can no longer lower it's discharged temp..

Now a hard headed moron like me, just can't get it out of my head.. That an air to air intercooler works by the principle of "CONVECTION".. And that there is some kind of rule of physics that dictates something with a high temperature (like inside of a coolers core).. Will migrate toward something cooler (like the fins around the core).. Where it will be dissipated into the cooler ambient air..

Sometime ago (on this board) I had a discussion with a guy that built top quality air to air intercoolers.. He claimed his intercoolers were 100% efficient ("which I didn't believe"), and he had the data logs to prove it.. He claimed that on a turbocharged import running 45 lbs of boost, with one of his intercoolers.. On a 70 degree day, his IAT's were 70 degrees.. And he had guys that backed him up with their own data logs.. That said the IAT's with air to air coolers were always the same as the ambient air temp..

Where are those guys at today... To give me some backup.. Sort of..
 

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Bellman,

I think you're confusing terms and application. The concept of an A2A as a heatsink is on a drag race only car.

Heat exchangers require a temperature difference to function. This is the basis of efficiency. (temp in-temp out) / temp in. An intercooler has to absorb the heat from the charge air before it can start rejecting it, and it won't start rejecting it at a high efficiency rate until the intercooler reaches the same temperature of the charge air. To add on to this, aluminum has a higher specific heat than air, which means mass-for-mass, aluminum can absorb more heat energy than air to reach the same temperature level. Air is roughly 1.005 j/kgc where aluminum is .921 j/kgc.

On a street car, this isn't a problem as there's plenty of time for the core to absorb AND shed heat, and the initial speed the vehicle is traveling when loaded is much higher than a drag car (from a standstill, obviously) so airflow over the core is higher on average than a drag car when comparing pull-for-pull. A drag vehicle (that uses an intercooler) will run between 6 and 12 seconds. There simply isn't enough time during the run for the core to heat up enough to start rejecting the heat it's absorbed. This is also the reason AWIC with ice work so well without a W2A heat exchanger. Water has a much higher specific heat than air and can "sink" a ton more heat energy with less temperature increase than an A2A
 

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On my 900hp single turbo street car I installed an A/A intercooler. During wot runs the air temp entering into the engine will get to ambient very quickly once i go wot and by the end of a 9 sec pass the air temp will be at most 5* higher than ambient temperature. The intercooler is more than a heat sink because air is passing thru the fins removing heat constantly. More air flow (mph), more heat removed.
 

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Since this is an air to water thread, I figured I’d throw in this intercooler pump that I stumbled on while doing research that I hadn’t seen before. I’m surprised more people aren't using it. I had an in tank Rule 3700. I immediately ordered another ice box with a strainer from Robert at Chiseled and bought one to run inline.

 

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On my 900hp single turbo street car I installed an A/A intercooler. During wot runs the air temp entering into the engine will get to ambient very quickly once i go wot and by the end of a 9 sec pass the air temp will be at most 5* higher than ambient temperature. The intercooler is more than a heat sink because air is passing thru the fins removing heat constantly. More air flow (mph), more heat removed.
Assuming you are running over 5-10lbs boost, there is no way on earth the air temperature downstream of a turbo could be within 5 deg F of ambient in a drag car unless the temperature is being measured downstream of the injectors.
 

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There are 3 modes of heat transfer - conduction, convection and radiation and the transfer rate of all are based on several factors. Two of those factors are delta T (T1-T2) but the take place. Disregard radiation because that is negligible in our discussion because of the low delta T. To start the heat transfer process, first the hot air from the tuirbo inside the intercooler transfers heat to the interior surfaces thru CONVECTION, then CONDUCTION thru the aluminum material starts to take place. The amount of heat transfer by convection on the interior is high because the delta T is already high - hot air from the turbo (T1) is in contact with the "cooler" aluminum material (T2). Once this starts, it takes time for the heat being transferred into the aluminum material thru convection to raise the exterior material surface temperature by conduction enough for the outside surface temperature to start any effective heat transfer thru conduction.

In other words - the instant the air inside the intercooler goes above the ambient exterior temperature there is ZERO heat transfer thru convection by the exterior surface of the intercooler. Equilibrium occurs when the convection heat transfer on the inside equals convection heat transfer on the outside. Even if it takes only 20--30 seconds for the exterior surfaces to reach an equilibrium temperature, the majority of heat transfer during the initial start of this process is into the aluminum material of the intercooler.

That is why we are using the term "heat sink" in this thread. In actuality, it's not a 100% heat sink as some heat transfer thru convection does occur from the exterior surfaces during a typical run, but this exterior heat transfer STARTS at 0% and probably only reaches something like 30-50% of it's equilibrium temperature in 10 seconds.
 
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