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Anyone use heater core to chill water in IC ?

13K views 84 replies 11 participants last post by  Ondatrack 
#1 ·
Been really wanting one of those chillers and have done a lot of searching. Came across this on another forum. Running your HE hose to your heater core. I Dont need a heater here for a good 8 months of the year. Could be pretty easy to just swap back anyway it seems.


I dont quite understand it myself. Would love to know how well it could work even if just for the track.

Turn the AC on and put the temp on full high and it will cool the air really cold and then blow it though the trucks heater core cooling the water in it to BELOW ambient. You just need to put a catch can on the HVAC drain to catch the drips from running the AC if your at the track.
It works quite well. I've had it on my truck for a few years now and I'll be rocking it again soon since its warming up again. You do lose the heater, so in the winter I run a convential A2W setup. But with meth and the chilled water my IAT's are consistently below ambient. Without meth IAT's are about ambient under boost at the end of a run. I'm really surprised this isn't more popular. It's probably the best mod for the money. If you have an A2W setup already (Radix, TVS etc) its just the price of heater hose.
Thread http://www.performancetrucks.net/forums/forced-induction-159/heater-core-heat-exchanger-459454/
 
#2 ·
instead of having a dedicated system like a super chiller the heater core mod lets you transfer the heat a different way. when you re-route the lines through the heater core and turn on the air conditioning the fluid going through the core is cooled by the AC so when it goes back into the coolant reservoir for the maggie it's cold. then the colder coolant in the reservoir passes through the heat exchanger under the maggie giving you colder air and more horsepower

It takes a couple minutes to reach full cooling power but that's okay because you can hot lap your car with a system like this. When you go full throttle the AC shuts of automatically so your not pushing the motor harder than you have to.

hope this answers your question

~Chris
 
#3 ·
wow that sounds great for 8 months out of the year . Have you tested to see what kind of IATs improvements you get with it running like this ? I wonder how cold it gets the water. I know those chillers get the water pretty low like 40-50 degrees. I cant imagine this works that well but would be awesome if it made a significant improvement. My IC water temps get well over 100 degrees. I wonder why more people dont do this mod :dunno:

Few questions ;

How hard/easy is it to do this mod ?

What exactly do I have to do and what do I need ?

Any way to make it easy to swap back and forth ?

Impossible to have the heater work with this mod correct ?

do you think it really needs a catch can for the track or could I just shut it down right before I make a run ?

Any pics ?

appreciate your help, this really seems like the way to go during the late spring/summer early fall.
 
#8 · (Edited)
Have you tested to see what kind of IATs improvements you get with it running like this? I wonder how cold it gets the water. I know those chillers get the water pretty low like 40-50 degrees. I cant imagine this works that well but would be awesome if it made a significant improvement. My IC water temps get well over 100 degrees. I wonder why more people dont do this mod :dunno:

Few questions ;

How hard/easy is it to do this mod ?

What exactly do I have to do and what do I need ?

Any way to make it easy to swap back and forth ?

Impossible to have the heater work with this mod correct ?

do you think it really needs a catch can for the track or could I just shut it down right before I make a run ?

Any pics ?

appreciate your help, this really seems like the way to go during the late spring/summer early fall.
The dedicated systems will chill the water down to a very cool temperature like 40-50 degrees for IAT's and IC fluid temp watch this video for an idea. you might not get that much efficiency with this system but it will still be much lower than what you are running now



No the heater will not work.

The swap will be easier when you learn how to do it.

you will have to have some coolant on reserve for this because you will loose some with each swap.

All NHRA certified tracks would appreciate a catch can.

I have no pics but this has been done before
 
#4 ·
This sounds like a good concept for those of us that only need a heater for a couple of months but in practice wouldn't the only time that you would have water and air going through the heater core be when you have the heater control on hot with the control set to heat or possibly vent. I was under the impression that when the AC is on a valve is shut that keeps the water from going through the core and that the internal doors are shut that would allow air to pass through the heater core. I may be mistaken but that was the way I understood it in a post that described the operation of the HVAC system. If this is correct then it could still provide some possible benefit in expanding the heat exchanger system a bit and with the fan on it would pulling more ambient temperature air over the core to cool the water some more. Is there something I am missing? Maybe something could be modified in the controls that would allow air and water through the heater core while the AC is on to actually chill the water but then it would not quite be a simple swap on a couple of hoses. Does anyone have a better understanding of the HVAC system to verify this?
 
#5 ·
There is always water (coolant) going through the heater core. basically, what happens when you switch from hot to cold, is a door in the HAVAC system will route the air either through the heater core (for hot air) or away from the heater core (cold air). so you would have to have the controls set to HOT to be able to maximize efficiency, so that as much air as possible was going over the heater core. Hope this helps
 
#6 ·
This is not my understanding of the GTO system.

My understanding was that we have no door and airflow is always passing over the heater core. There is a bypass valve on the passenger side frame rail that will disable coolant flow to the heater core when you switch from hot to cold.

This idea has potential and it would take $20 and 5 minutes to try other than burping the radiator again. I'm just not sure how efficient it would be and I'm not sure how hot it will make the interior temps. Done correctly I also don't see how you would lose your heater, just turn off the AC compressor and whala hot air.
 
#9 ·
One guy did say the temps dropped down to 40 degees doing this on his truck .


So you use both the heat exchanger and the heater core correct ?

Sounds easy to do I just want to make sure I do it correctly.

I dont need any different sized fittings / hoses etc ?

What do you do with the hoses already going to the heater core from the motor ?

Do I run the hoses from the HE to the heater core or from the reservoir to the heater core ?


Just want to make sure I know what I need and dont get surprised when I get under there. Mainly want to make sure I hook it up correctly.
 
#11 ·
The diagram I have of the Core box clearly shows 2 Blend doors. I'm 99.9% certain they are cable operated, been a while since ive been in the dash. At some point it also triggers the water valve.

Air comes across the Evaporator first, all the time. Then if you have it set to heat, the doors open allowing a path across the heater core. This is done so that In defrost mode the compressor is on dehumidfying the air coming across the evaporator.

I dont know how well this idea would work, but Its certainly worth playing with. You'd have to set the dial to full heat. The heat transfer rates for heater cores tend to be worse than that of evaporators. You get far less heat out than you put in. 220* ECT is fairly common, yet its rare to get vent temps over 170. Usually 140-160. Not being an FI guy, I dont know what temps you guys are seeing out of the IC, but id imagine they are pretty high. High enough to heat the car even with the A/C on. So if you do this, plumb it in BEFORE the IC.
 
#12 ·
Good info, thanks. Not many people have done this but the ones that have say it works quite well to lower your IATs. Seems like a larger reservoir would really help to with a system like this. IATs are over 150 degrees .

I'd really like some kind of basic diagram of how to route everything and in what order.
 
#16 ·
Some are saying it gets the water down to 40-50 degrees which is as good as one of those chillers and those have certainly been proven to drastically drop IATs. My water gets well over 100 degrees after romping on it. Hell I tried putting a bunch of ice in my reservoir at the track and it still didnt get the water very cool at all. Even if it dropped that water temp to 60-70 it would be a big improvement at the track and DD.

Making a system that is easy to swap back and forth would be cool. Maybe with some kind of bypass valves or something ......


Wish someone could draw a basic diagram of how to route this.

So take the IC hose that normally goes to the to the manifold inlet and route it to the heater core and then back into the manifold correct ? Water exiting the manifold goes to the reservoir ?

What do you do with the hoses that are on the heater core already ?
 
#17 ·
This is from the post on the HVAC system I had read. This is why I was thinking the core doesn't always have water flowing through it. Sorry but I don't know how to just post the link to the thread.

Also found this under "Air Temperature Description and Operation".

The HVAC control assembly is a non-class 2 device that interfaces between the operator and the HVAC system to maintain air temperature and distribution settings. The HVAC unit is operated manually by a combination of electrical, mechanical and vacuum components. The case is of a 4-piece, plastic construction. The front and rear housing are assembled without the use of any fasteners. The front housing clips over the rear housing at 6 locations. Two equally sized recirculation doors are used to control airflow into the HVAC unit. Two air mix doors are used to control the airflow through the heater core. A single door is used to control airflow to the front defrost, floor and panel outlets. All doors excluding the air mix doors are vacuum operated. The air mix doors are operated mechanically. The blower motor/fan assembly, blower motor resistor, heater core and evaporator are all contained within the HVAC case. A vacuum tank is mounted to the left side of the case. Four externally mounted vacuum actuators are used to provide the selected ventilation modes. Contained within this assembly is a printed circuit board retained within the rear housing.

Temperature Switch
When the temperature switch is turned clockwise from the coldest position to the hottest position, the pinion and crescent gear mounted to the rear of the controller are rotated. This action simultaneously opens airflow through the heater core and cuts off vacuum to the water valve allowing heated coolant to flow through the heater core.

Cold Operation
Vacuum generated within the inlet manifold of the engine is stored within the vacuum tank mounted on the side the HVAC unit. Vacuum is retained within the HVAC system by the one way check valve and is directed to the water valve vacuum switch mounted to the rear of the HVAC controller. When the temperature switch is turned to the Full Cold position, the pinion gear rotates the crescent gear so that the ramp on the crescent gear pushes the plunger inside the water valve vacuum switch inward against spring pressure. In this position, the water valve vacuum switch allows vacuum to be directed to the water valve. When vacuum is applied to the water valve vacuum actuator, no coolant can flow through the heater core. However, coolant is still able to flow from the engine through the water valve via its engine side ports and engine side heater hoses. The crescent gear is also mechanically connected to the HVAC air mix doors via the actuating rod and levers. As well as operating the plunger of the water valve vacuum switch, the crescent gear simultaneously locates the air mix door in a position that does not allow any air to flow through the heater core in the Full Cold mode. The result is that all air entering the vehicle cabin will be cold air.

Warm Operation
When the temperature switch is turned from the Full Cold position, the crescent gear rotates backwards moving the ramp away from the plunger of the water valve vacuum switch. Spring pressure moves the plunger outward and at the third detent position, the vacuum line to the water valve actuator is vented through the exhaust port of the water valve vacuum switch. When the actuator is relieved of vacuum, the disc in the water valve will rotate and allow hot water to flow through the cabin side water valve ports and the cabin side heater hoses into the heater core. As the crescent gear rotates backward, it pulls the air mix doors open. When the temperature switch is turned to a Warm position, the air mix doors will be partially open. This will cause some incoming air to pass through the heater core and some to air to bypass the heater core. The mixture of heated and cool air will result in warm air entering the vehicle cabin.

Hot Operation
When the temperature switch is turned to in the Full Hot position the water valve vacuum switch plunger remains in the same position. Therefore, the water valve remains in the fully open position because the water valve actuator is devoid of vacuum. In the Full Hot position the crescent gear will be rotated fully rearward. This action will move the air mix doors to a position that directs all incoming air through the heater core. Therefore, all air entering the vehicle cabin will be heated air.
 
#33 ·
Please bare with me on this. Just want to make sure that I read and understood this correctly

cold operation= no flow of coolant to core, air mix door does not allow airflow over core

warm operation= coolant valve fully open, air mix door allows some air over core

hot operation= coolant valve fully open, all air directed over core

Right?

So if I ran my S/C coolant through the heater core I would need to have the hvac controls set to hot with the A/C compressor on?

scooter0803 said:
Water Valve
The heater water valve is located in the engine bay. The vacuum line attached to the water valve vacuum actuator is connected to the water valve vacuum switch mounted on the HVAC controller. When full vacuum is applied to the water valve actuator, full closure of the valve occurs and no coolant will flow through the heater core.
but..

ondatrack said:
When vacuum is applied to the water valve vacuum actuator, no coolant can flow through the heater core. However, coolant is still able to flow from the engine through the water valve via its engine side ports and engine side heater hoses.
What does that mean? If I turn from hot to cold is it going to shut off the coolant to the supercharger?
 
#18 ·
I can attest to using the factory a/c setup. I've been running a much simpler setup for about 2 years now with great success. I was working on building a stand alone system for vehicles, but I was hindered by supplier issues and more importantly weight. I just don't think its feasable to carry around another cooling system when you already have the factory one right there.

Anyway, I borrowed the idea from a guy on here named Duner. I'm not sure if he hangs around much anymore, but nevertheless it works. The downside is you lose your heater, but in the summer who really cares. I never use my heater here anyway, so I use the setup year round. Bascially you have an a2w IC, with a pump and everything, and then you route the coolant lines to the heater core. When you turn on your a/c, you set the **** to heat. The fan then blows the air across the evap coil onto the heater coil, thus pulling heat out of the water. It takes longer to cool off the cab, but like Rick said, below ambient IAT's ALL DAY LONG! Even under boost. At idle in the middle of the summer (+100* ambiet), while stuck in traffic, IAT's would be a little below ambient. Step on the gas to go, and they drop instantly.

At the end of a 1/4mi run they start to climb, but that probably had to do with my lack of reservoir capacity. I never played with pump speed, but I'm sure there's more to be had there as well. An evap coil submerged in water would be even more effective IMO, but I worry about what it'll do to the in cab temperatures too. You might have to play with the orifice size and the amount of refrigerant. A variable orifice for sever conditions would probably be the best way to go.

I know that with no reservior, and driving it really hard, like a full 1/4mi it would be blowing luke warm air. Not hot, but not cold either. I've never measured the air temp across the heater core though, just the IAT's.

It's really quite interesting, because as soon as you get into boost the IAT's drop further from where they were while cruising. With meth and chilled water, on a 90* day, my IAT's were 50* at the begining of a run and ~65* at the end. That's with 10-12psi on a 4.8. I shut the a/c off in stagging too, since the IC and water will stay cold for quite awhile depsite the a/c running.

I think I'm going to due something similar to my Ty since the IC sits on top of the damned engine.
 
#19 ·
Konnie is correct in that you would want to blow off as much heat as possible through the front heat exchanger before attempting to drop it below ambient with the heater core.
 
#20 ·
Most of this may have been said already, but this is directly off of GM Service Information.

HVAC Control Components

The HVAC control assembly is a non-class 2 device that interfaces between the operator and the HVAC system to maintain air temperature and distribution settings. The HVAC unit is operated manually by a combination of electrical, mechanical and vacuum components. The case is of a 4-piece, plastic construction. The front and rear housing are assembled without the use of any fasteners. The front housing clips over the rear housing at 6 locations. Two equally sized recirculation doors are used to control airflow into the HVAC unit. Two air mix doors are used to control the airflow through the heater core. A single door is used to control airflow to the front defrost, floor and panel outlets. All doors excluding the air mix doors are vacuum operated. The air mix doors are operated mechanically. The blower motor/fan assembly, blower motor resistor, heater core and evaporator are all contained within the HVAC case. A vacuum tank is mounted to the left side of the case. Four externally mounted vacuum actuators are used to provide the selected ventilation modes. Contained within this assembly is a printed circuit board retained within the rear housing.

Hot Operation
When the temperature switch is turned to in the Full Hot position the water valve vacuum switch plunger remains in the same position. Therefore, the water valve remains in the fully open position because the water valve actuator is devoid of vacuum. In the Full Hot position the crescent gear will be rotated fully rearward. This action will move the air mix doors to a position that directs all incoming air through the heater core. Therefore, all air entering the vehicle cabin will be heated air.

Water Valve
The heater water valve is located in the engine bay. The vacuum line attached to the water valve vacuum actuator is connected to the water valve vacuum switch mounted on the HVAC controller. When full vacuum is applied to the water valve actuator, full closure of the valve occurs and no coolant will flow through the heater core.


If there is any more infor you need, which there is a lot that I left out, just let me know and I can post them
 
#21 ·
Coolant Resevoir

Would it be beneficial and or worth the trouble to relocate the battery and have a large reservoir located where the battery was with one of those big openings to put ice in it like some of the SVT guys do? I wouldn't mind going to the trouble of putting ice in there every time i go to the track.
 
#22 ·
Would it be beneficial and or worth the trouble to relocate the battery and have a large reservoir located where the battery was with one of those big openings to put ice in it like some of the SVT guys do? I wouldn't mind going to the trouble of putting ice in there every time i go to the track.
I'd rather leave the battery and relocate the tank. That being said I relocated both.
 
#23 ·
Could anyone break it down for me how to route this puppy and what would be needed besides a little coolant.
 
#24 · (Edited)
There is a U bend hose that most parts stores sell, I forget the part #, but you put that on the water pump outlets so that they are connected to each other.

Then remove the hose from the blower to your water tank. You will have two hoses from the heater core. One goes to the blower, the other to the water tank.

It should go tank - heater core - blower - heat exchanger then repeat.
 
#31 ·
Just went out to garage to test the temp. Engine off for 3 hours , garage is very cool maybe 60-70 degrees. IC reservoir temp is exactly 96 degrees. It must get to over 130 when getting into boost at all. If it drops those temps to 50-60 we should be golden and have some very nice IATs as a result.
 
#36 ·
Doesn't the valve when closed to the heater core open to the bottom allowing the water to loop back to the water pump normally or in this case back to he heat exchanger in the supercharger bypassing the heater core altogether.

Konnie, when I do this and if I remove the valve and let the warm intercooler water flow through the heater core continually, will the AC with the control placed on cold still cool just like there was no water flowing through the core since the door would be closed keeping the cold air from going over the heater core. I realize that I would not be cooling the heat exchanger water in this mode. I just am wondering if even with the door closed would the radiant heat from the heater core be enough to decrease the AC efficiency when keeping the cabin cool is more important than chilling the supercharger?
 
#37 ·
Konnie. Cut the HVAC thingamajig in two with the band saw. Post up results.
 
#39 ·
Yea, I just got a chance to look at the valve and it looks like it would be easier to tie into the heater core on the firewall side of the valve by passing the valve all together. Won't have to worry about the valve being a restriction. The only thing that I don't like are the sizes of the heater core hose.
 
#41 ·
wouldnt you just use the hoses that attach to the water pump and put one on the reservoir and the other to the IC ? I am ready to try this but want to make sure I have this correct.
 
#40 ·
For a setup like this, I would suggest something like a Shurflo Aqua Tiger as a coolant pump, and regulate the speed with a PWM controller. Finding the optimal coolant flow rate would be essential to having something like this work well.
 
#42 ·
Today I drove my car a bit and got in to boost a decent amount. Water was up to 110 degrees. Not as hot as I thought it was going to be. I guess the IC is helping a lot while I was driving.
 
#45 ·
I was thinking about doing this mod full time since it isnt terribly cold here. Seeing how the water temp in my IC is usually around 100 degrees when cruising around probably a bit higher when in boost, do you think it would still give decent heating if needed ? It wont be 160-180 degrees but would probably be around 110 I think. We dont get really cold weather here. The coldest part of winter it still gets up to the 50s. Hell it was 80 here today. I wonder though if it is only in the 30s-40s outside if that IC water will then be much cooler then the average 100 degree temps :dunno:
 
#50 ·
Got the parts today, hope to be able to try it tomorrow. Was about $30 for everything needed.
 
#51 ·
I am glad to see you trying this, good luck. Are you maintaining the original coolant flow route or are you reversing it? If reversing are you putting the heater core between the heat exchanger and the tank or between the tank and the superchargers inter cooler?

Tony
 
#52 · (Edited)
What do you think would be best ? I thought one hose from heater core goes to the intercooler and one goes to the tank and that was pretty much it. Of course I will have a U-bend for the water pump. It does look like one hose is 3/4 and one is 5/8ths from the heater core.


Best I can figure is the coolant is going from the heat exchanger to the intercooler. Then the exiting water from intercooler goes to the heater core and back to the reservoir.
 
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