Yellow Bullet Forums banner

21 - 40 of 72 Posts

·
Registered
Joined
·
3,755 Posts
Thanks for the input.
I'm going to give the A/W a try without an on board resevoir or pump.
I'll cool it down with a cool down unit between rounds.
If I don't like what's happening, I'll add the reservoir and pump.
I've often wondered if there was a fluid you could put in an A/W that would cool quicker than water. As an example, if you could fill it with isopropyl, loop the in and out hoses and then cool it back down between rounds. I probably thought of isopropyl because of how cold it is when it's evaporating off the hand, (which obviously wouldn't be happening). Would be a fun experiment.
 

·
Registered
Joined
·
6,853 Posts
I've often wondered if there was a fluid you could put in an A/W that would cool quicker than water. As an example, if you could fill it with isopropyl, loop the in and out hoses and then cool it back down between rounds. I probably thought of isopropyl because of how cold it is when it's evaporating off the hand, (which obviously wouldn't be happening). Would be a fun experiment.
According to heat transfer rate charts, it's hard to beat water. You are correct that the evaporation of solvents happens quickly, and thus can result in cooling. But that doesn't happen when you keep it in the liquid form. Just when you vaporize it, which you don't want to do for pressure reasons in a closed loop a/l cooling system. If you want to cool with a solvent, inject it into the intake tract and let it vaporize. Using methanol instead of water benefits from the coolant actually being flammable instead of wanting to dilute the flammability.
 

·
Registered
Joined
·
3,494 Posts
Well let me give my 2 cents on this intercooler question, since I do run a large air to air..

An air to air does NOT have to reach a temperature equilibrium before it starts to cool.. And it definitely is effective immediately when subjected to hot air..

When you go full boost, a turbo starts blowing 2 or 300 degree heat right off the bat.. After a full run on my 1400+ rwhp car, I can get out and put my hand on my air to air.. And the right side of the cooler (at the turbo discharge) will burn the crap out of you.. If you touch the left side of the cooler, the temp is hundreds of degrees lower..

Below is a picture of my air to air setup.. The picture below that is how it gets air flow with the front nose on the car.. The third pic is data logged shot at the end of quartermile run with 3.27 rear gears.. You can see my intake air temp.. That temp was with the addition to the air to air cooler, a 50/50 water meth spraying directly into the turbo intake.. And you can see my old 3 bar map sensor pegged out at 30 lbs of boost.. It was probably 32 to 34 pounds really..

These are MY experiences... Your's may differ...

78550




78551




78552
 

·
Drag Week Survivor
Joined
·
14,382 Posts
Im at 75 degrees at the launch and 100 at the 1/8 , and 125 at the 1/4 . Ice in 5 gal reservoir 34psi of boost . No pre cooling , just turning the pump on after the burn out .

If you can achieve under 150 degrees at the 1/8 on C16 using just the water in the core , I think you should be fine . A lot of guys running much higher on blow-thrus with no coolers

Try precooling in the lanes a few minutes before your pass.

I started turning my pump on with about 4 pairs of cars in front of me. My starting temp went from 71° to 61° and in a mid 8 second 1/4 mile pass I wouldn't see over 100° in the plenum under the throttle body elbow.
 

·
Registered
Joined
·
23,546 Posts
Try precooling in the lanes a few minutes before your pass.

I started turning my pump on with about 4 pairs of cars in front of me. My starting temp went from 71° to 61° and in a mid 8 second 1/4 mile pass I wouldn't see over 100° in the plenum under the throttle body elbow.

Ill give it a try next time I get to the track . When ever that will be .
 

·
Registered
Joined
·
53 Posts
Well let me give my 2 cents on this intercooler question, since I do run a large air to air..

An air to air does NOT have to reach a temperature equilibrium before it starts to cool.. And it definitely is effective immediately when subjected to hot air..

When you go full boost, a turbo starts blowing 2 or 300 degree heat right off the bat.. After a full run on my 1400+ rwhp car, I can get out and put my hand on my air to air.. And the right side of the cooler (at the turbo discharge) will burn the crap out of you.. If you touch the left side of the cooler, the temp is hundreds of degrees lower..

Below is a picture of my air to air setup.. The picture below that is how it gets air flow with the front nose on the car.. The third pic is data logged shot at the end of quartermile run with 3.27 rear gears.. You can see my intake air temp.. That temp was with the addition to the air to air cooler, a 50/50 water meth spraying directly into the turbo intake.. And you can see my old 3 bar map sensor pegged out at 30 lbs of boost.. It was probably 32 to 34 pounds really..

These are MY experiences... Your's may differ...

View attachment 78550
What you are describing is a heat sink doing it's job. The intercooler is not cooling the air but it is transferring heat to the core. The longer the pull you do the larger the "hot" area will be. If you did a pull long enough that hot area will grow towards the passenger side for sure. This is why when we build air to air IC's we use the biggest core we can possibly fit always. 6" thick by 24" by 12.75" core was one of the larger ones we have squeezed in behind the stock front bumper. The A/A IC's job is to soak up the heat to help control the rise over the run. There are a ton of cheap A/A cores out there that will heat up much quicker than the same size Garrett core. All cores are not created equally. This is why a W/A are superior because you can chill them to give it a headstart and in a proper system your water and ice tank setup will slow the rise of the temp of the water which then in turn makes the core that much more effective.

ALEX...
This is a simple way to put it without calling anyone names... I know this is the bullet but it's always best to explain this stuff in a manner which someone is more likely to adopt what you are saying. Starting out by calling someone a retard and then spending your time trying to school them... well. you see how that worked haha
 

·
Registered
Joined
·
3,494 Posts
What you are describing is a heat sink doing it's job. The intercooler is not cooling the air but it is transferring heat to the core. The longer the pull you do the larger the "hot" area will be. If you did a pull long enough that hot area will grow towards the passenger side for sure. This is why when we build air to air IC's we use the biggest core we can possibly fit always. 6" thick by 24" by 12.75" core was one of the larger ones we have squeezed in behind the stock front bumper. The A/A IC's job is to soak up the heat to help control the rise over the run. There are a ton of cheap A/A cores out there that will heat up much quicker than the same size Garrett core. All cores are not created equally. This is why a W/A are superior because you can chill them to give it a headstart and in a proper system your water and ice tank setup will slow the rise of the temp of the water which then in turn makes the core that much more effective.

ALEX...
This is a simple way to put it without calling anyone names... I know this is the bullet but it's always best to explain this stuff in a manner which someone is more likely to adopt what you are saying. Starting out by calling someone a retard and then spending your time trying to school them... well. you see how that worked haha

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,,
 

·
Registered
Joined
·
16,365 Posts
First, here's what I know as a Mechanical Engineer. An A/A does act basically as a heat sink during drag car's pass. Not enough time for thermal transfer during a pass to develop any significant temperature gradient needed to reject heat to the air. And even a A/W also acts like a heat sink during the run for the same reason.

Here's my experience. I have a car with an A/W intercooler using a closed loop water system. It holds 2-1/2 gallons of water and a pump circulates the water thru a B&M transmission cooler that helps cool the water temperature between runs. I wanted a system that was more effective than the original A/A but didn't want to have to deal with draining the system between rounds and filling with ice.

What's interesting is my A/W intercooler started life as an A/A unit and I enclosed the air fins with covers to create a reservoir. Same car, same intercooler core. IAT at the beginning of the run were similar for both since everything on both setups get heat soaked due to it's location near the engine and radiator. During a run with the intercooler as an A/A unit, I would see approximately 200 deg F IAT at the end of the quarter miles. At the same boost, with the core covered with water I would see closer to 150 deg F. During the run with the A/W, the water temperature in the intercooler only rises 3 deg F.

Interpretation of the actual data from the A/W setup shows this - even though the water is capable of transferring heat much faster, during the run it only absorbed enough heat to raise the water temperature of 2-1/2 gallons of water 3 deg. However, with the water it becomes a more effective heat sink than the A/A intercooler so the final IATs are lower.

If you're going to cool it off between runs a good compromise would be to leave the A/W intercooler core filled with water and seal it off. Then after the run drain the water, wait 10-15 minutes then refill it with water. I would leave a little air in the cooler to allow for expansion of the water. On my system it is filled 100% but has a fill line running to a tiny overflow reservoir with a radiator pressure cap.

Here are 2 pictures of the same intercooler as an A/A and converted to an A/W.

81006


81007
 

·
Registered
Joined
·
3,494 Posts
First, here's what I know as a Mechanical Engineer. An A/A does act basically as a heat sink during drag car's pass. Not enough time for thermal transfer during a pass to develop any significant temperature gradient needed to reject heat to the air. And even a A/W also acts like a heat sink during the run for the same reason.

What's interesting is my A/W intercooler started life as an A/A unit and I enclosed the air fins with covers to create a reservoir. Same car, same intercooler core. IAT at the beginning of the run were similar for both since everything on both setups get heat soaked due to it's location near the engine and radiator. During a run with the intercooler as an A/A unit, I would see approximately 200 deg F IAT at the end of the quarter miles. At the same boost, with the core covered with water I would see closer to 150 deg F. During the run with the A/W, the water temperature in the intercooler only rises 3 deg F.
That was pretty slick the way you enclosed the core.. That idea had crossed my mind also..

This is where I must be missing something, with this whole "heat sink" idea..

When put your gas pedal to the floor on a turbo car.. That motor pretty rapidly start making a lot of power.. That power comes from a lot of air passing through the core of the intercooler.. And also pretty rapidly, the turbo starts discharging 200+ degree heat..

Something has to be cooling off the 200 degree heat before it makes out of the intercooler.. And I don't think it's just being absorbed.. Take away any airflow over the cooler, and watch your IAT go thru the roof..
 

·
Registered
Joined
·
16,365 Posts
That was pretty slick the way you enclosed the core.. That idea had crossed my mind also..

This is where I must be missing something, with this whole "heat sink" idea..

When put your gas pedal to the floor on a turbo car.. That motor pretty rapidly start making a lot of power.. That power comes from a lot of air passing through the core of the intercooler.. And also pretty rapidly, the turbo starts discharging 200+ degree heat..

Something has to be cooling off the 200 degree heat before it makes out of the intercooler.. And I don't think it's just being absorbed.. Take away any airflow over the cooler, and watch your IAT go thru the roof..
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.
 

·
Registered
Joined
·
179 Posts
Better idea get a giant block of aluminum and make an intercooler out of it. Put some passages through it and run refrigerant through it. Get the giant metal block cooled down to like -40F prior to your run. This should work great as an intercooler for 10 seconds.
 

·
Registered
Joined
·
179 Posts
Interesting side topic on heat management. I read about a guy that was building a reno race plane that had no cooling ducts to cool the engine. This greatly reduced cooling drag. He used the skin of the fuselage of the airplane as the cooler to keep the engine cool for the race.
 

·
Registered
Joined
·
179 Posts
Also what about a evaporative cooling intercooler? Instead of surrounding the core with water you spray water or something else on the core to pick up the temp drop of vaporizing the liquid thereby reducing the temp lower than ambient water.
 

·
Registered
Joined
·
179 Posts
I am talking about a closed system type one. Sprays through the intercooler and then condenses back to liquid at the bottom.
 

·
Registered
Joined
·
16,365 Posts
Better idea get a giant block of aluminum and make an intercooler out of it. Put some passages through it and run refrigerant through it. Get the giant metal block cooled down to like -40F prior to your run. This should work great as an intercooler for 10 seconds.
Too difficult to get surface area. Surface area is one of the largest factors in heat transfer.
 

·
Registered
Joined
·
16,365 Posts
I am talking about a closed system type one. Sprays through the intercooler and then condenses back to liquid at the bottom.
Too complicated. You're describing an evaporative cooling system. You would need a pump to compress the vapor to a fluid then run it thru another heat exchanger to reject the heat from compressing the vapor. Otherwise the liquid/vapor will not circulate.
 

·
Registered
Joined
·
245 Posts
Yeah you couldn't keep a compressor onboard powerful enough to disapate the heat. A better option would be to run a glycol mixture and use a gas generator powered trailer mounted compressor to supercool the awic reservoir while you're in the lanes. -040f coolant temperatures, anyone?
 

·
Registered
Joined
·
179 Posts
TopFun99 not a refrigeration cycle. Some of the spray will not vaporize on the intercooler and just pass through to the sump to be pumped again. This is not a pressurized system.
 

·
Registered
Joined
·
16,365 Posts
TopFun99 not a refrigeration cycle. Some of the spray will not vaporize on the intercooler and just pass through to the sump to be pumped again. This is not a pressurized system.
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.
 
21 - 40 of 72 Posts
Top