Plumbing my A/C to cool my throttle body... ehm, instead of heating it.
#1
Cruising
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Plumbing my A/C to cool my throttle body... ehm, instead of heating it.
Im not driving my C4 in the cold. At least not this summer. So my thought is to use the super high tech and also hollow throttle body to hold super cold
refrigerant, instead of hot coolant. I could plumb cold refrigerant from the low side of the evaporator. That should be dry ice cold. I wonder if I could put threads on the two Male coolant fittings on the throttle body? I think there is enough room for more than enough threads there. Enough to handle a couple hundred psi anyways... Do you guys think the gaskets it the throttle body would have to be changed out and likely custom made? If so what martial are refridgersnt gaskets made of? PAG rated?
refrigerant, instead of hot coolant. I could plumb cold refrigerant from the low side of the evaporator. That should be dry ice cold. I wonder if I could put threads on the two Male coolant fittings on the throttle body? I think there is enough room for more than enough threads there. Enough to handle a couple hundred psi anyways... Do you guys think the gaskets it the throttle body would have to be changed out and likely custom made? If so what martial are refridgersnt gaskets made of? PAG rated?
#2
Team Owner
Not enough performance gain to be worth the effort!
#3
Race Director
It's not like the air is passing through intercooler bricks like in a C6ZR1 or a C7Z before entering the engine. The air passing through the throttle body barely has any contact with it's 2" surface. As Mack said, very little gain, in fact negative gain when you factor in running the ac compressor.
#4
Le Mans Master
It's not like the air is passing through intercooler bricks like in a C6ZR1 or a C7Z before entering the engine. The air passing through the throttle body barely has any contact with it's 2" surface. As Mack said, very little gain, in fact negative gain when you factor in running the ac compressor.
It also could cause a sticky throttle. The purpose of the engine coolant (heat) was to prevent icing that might restrict throttle blade movement. Adding a "super cold" refrigerant instead of heat could cause the icing.
Last edited by QCVette; 04-15-2019 at 09:00 AM.
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#5
Melting Slicks
It is also not how refrigeration works. The exit side of the evaporator contains gas, not liquid and has already gone through its phase change and the associated latent heat after passing through the expansion valve. The amount of sensible heat it would pick up in the throttle body is miniscule. Regardless, at no point in the AC system would you approach "dry ice" conditions.
#7
Im not driving my C4 in the cold. At least not this summer. So my thought is to use the super high tech and also hollow throttle body to hold super cold
refrigerant, instead of hot coolant. I could plumb cold refrigerant from the low side of the evaporator. That should be dry ice cold. I wonder if I could put threads on the two Male coolant fittings on the throttle body? I think there is enough room for more than enough threads there. Enough to handle a couple hundred psi anyways... Do you guys think the gaskets it the throttle body would have to be changed out and likely custom made? If so what martial are refridgersnt gaskets made of? PAG rated?
refrigerant, instead of hot coolant. I could plumb cold refrigerant from the low side of the evaporator. That should be dry ice cold. I wonder if I could put threads on the two Male coolant fittings on the throttle body? I think there is enough room for more than enough threads there. Enough to handle a couple hundred psi anyways... Do you guys think the gaskets it the throttle body would have to be changed out and likely custom made? If so what martial are refridgersnt gaskets made of? PAG rated?
I also don't think the throttle body itself will seal several hundred PSI. The hoses might seal but the throttle body itself wont.
#8
Melting Slicks
You will get zero gain from this and you might reduce the efficiency of your AC. Any hp gain you would theoretically get at the throttle body would be eaten up with a corresponding loss from extra load on the AC pump.
I also don't think the throttle body itself will seal several hundred PSI. The hoses might seal but the throttle body itself wont.
I also don't think the throttle body itself will seal several hundred PSI. The hoses might seal but the throttle body itself wont.
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#9
Le Mans Master
It's not practical on a Corvette. It would require a custom heat exchanger and intake. It would not fit under hood with out a 6 inch or more scoop. Trying to duct cold air from evaporator case or moving evaporator itself - there is no space.
#10
Melting Slicks
The system pressure in a non-operating system in an under hood environment on a summer day just after engine shut down (system = OFF) will rise to much higher than 45psi. More like 150- ish. The pressure will equalize throughout the system.
The water manifold is attached to the bottom of the throttle body with screws and a gasket. This gasket won't hold refrigerant at any pressure.
The water manifold is attached to the bottom of the throttle body with screws and a gasket. This gasket won't hold refrigerant at any pressure.
#11
Le Mans Master
As previously stated, you'd lose any performance advantage of a cool TB to the cost of running the A/C. Suggest you look into methanol injection instead. This will lower your intake temps by 40-50 degrees and will be a lot simpler to install.
If you want to do something DIY, you can always coat the inside of your intake with epoxy. We did this on our LT1 impalas and it was good for around 2 tenths in the quarter - about the same as putting a bag of ice on the intake.
If you want to do something DIY, you can always coat the inside of your intake with epoxy. We did this on our LT1 impalas and it was good for around 2 tenths in the quarter - about the same as putting a bag of ice on the intake.
#12
The 45 PSI you see is with the engine on and the AC running. When the AC is on the compressor will pull a vacuum on the cold side relative to the hot side and regulate it to about 50psig, while the hot side can be over 300psig on a hot day. When you turn the engine off the compressor stops and the hot and cold side will equalize over time.
Go measure the suction side when the car is hot and has been off for 20 minutes and is not running. That is when the pressure will be highest and that is when he has to worry about it leaking.
Last edited by auburn2; 04-16-2019 at 06:48 PM.
#13
Drifting
Im not driving my C4 in the cold. At least not this summer. So my thought is to use the super high tech and also hollow throttle body to hold super cold
refrigerant, instead of hot coolant. I could plumb cold refrigerant from the low side of the evaporator. That should be dry ice cold.
refrigerant, instead of hot coolant. I could plumb cold refrigerant from the low side of the evaporator. That should be dry ice cold.
#14
Melting Slicks
The highest pressure on the cold side will be when the car is not running and on a hot day it can be well over 150psi.
The 45 PSI you see is with the engine on and the AC running. When the AC is on the compressor will pull a vacuum on the cold side relative to the hot side and regulate it to about 50psig, while the hot side can be over 300psig on a hot day. When you turn the engine off the compressor stops and the hot and cold side will equalize over time.
Go measure the suction side when the car is hot and has been off for 20 minutes and is not running. That is when the pressure will be highest and that is when he has to worry about it leaking.
The 45 PSI you see is with the engine on and the AC running. When the AC is on the compressor will pull a vacuum on the cold side relative to the hot side and regulate it to about 50psig, while the hot side can be over 300psig on a hot day. When you turn the engine off the compressor stops and the hot and cold side will equalize over time.
Go measure the suction side when the car is hot and has been off for 20 minutes and is not running. That is when the pressure will be highest and that is when he has to worry about it leaking.
#15
Le Mans Master
#16
Drifting
#17
Safety Car
Bypassing a throttle body on a C4 Corvette may be okay but I have had major carburetor icing after disconnecting the hot air flow through the intake manifolds on VW's. The Icing happened here in Virginia in the late summer and is a very real problem on VW's. To be able to drive the car I had to re-install the original heated intake manifold.
I replaced my throttle body when in fact all I needed was the lower body for the throttle body. The lower section has the coolant flowing through it and the screws and part of the body were very soft from corrosion due to old coolant. Where does one get a replacement for the lower part of the throttle body?
The idea of a Methanol injection system is a good one if you want to cool down the combustion a bit. I use the SNOW Performance Water/Methanol injection system on my 1968 C3 and it does wonders for hot running engines. First the methanol makes the gasoline have an equivalent octane of 115 and the water cools and slows the combustion process. I use it because of the High compression but the water makes a huge difference in operating temperatures. The best part is that you can use windshield washing fluid for the injection system. Windshield washer fluid is frequently 50-50 methanol and water. The trick with a methanol injection system is to be sure that it doesn't fill your cylinders with water and hydro-lock your engine. I have two injectors and they have a flow solenoid that stops all flow when I turn it off or shut the engine down. Using the methanol injection systems I frequently hear people talking about mixing their own methanol. SNOW says no more than 50-50. Methanol like many alcohols will burn clear and that is not good if it finds a source of flame. It does not give you the rush that Nitrous does when activated. My system uses the vacuum of the engine to control the flow and that works very nicely. I am finishing up the new -4 AN SS PTFE braided lines for the system to make it look better and be more secure.
I hope the project ends up where you intended it to!
Good Luck!
I replaced my throttle body when in fact all I needed was the lower body for the throttle body. The lower section has the coolant flowing through it and the screws and part of the body were very soft from corrosion due to old coolant. Where does one get a replacement for the lower part of the throttle body?
The idea of a Methanol injection system is a good one if you want to cool down the combustion a bit. I use the SNOW Performance Water/Methanol injection system on my 1968 C3 and it does wonders for hot running engines. First the methanol makes the gasoline have an equivalent octane of 115 and the water cools and slows the combustion process. I use it because of the High compression but the water makes a huge difference in operating temperatures. The best part is that you can use windshield washing fluid for the injection system. Windshield washer fluid is frequently 50-50 methanol and water. The trick with a methanol injection system is to be sure that it doesn't fill your cylinders with water and hydro-lock your engine. I have two injectors and they have a flow solenoid that stops all flow when I turn it off or shut the engine down. Using the methanol injection systems I frequently hear people talking about mixing their own methanol. SNOW says no more than 50-50. Methanol like many alcohols will burn clear and that is not good if it finds a source of flame. It does not give you the rush that Nitrous does when activated. My system uses the vacuum of the engine to control the flow and that works very nicely. I am finishing up the new -4 AN SS PTFE braided lines for the system to make it look better and be more secure.
I hope the project ends up where you intended it to!
Good Luck!
#18
Team Owner
Pro Mechanic
Bypassing a throttle body on a C4 Corvette may be okay but I have had major carburetor icing after disconnecting the hot air flow through the intake manifolds on VW's. The Icing happened here in Virginia in the late summer and is a very real problem on VW's. To be able to drive the car I had to re-install the original heated intake manifold.
OP could run the AC suction line (which is cold all the way to the compressor) through the TB coolant channels, run the AC in the staging lanes, then shut it off as he stages. I run my AC in the staging lanes anyway, to keep my coolant temps low. So...it's not THAT far fetched an idea.
I agree that it wouldn't do much, w/the speed the air flows through the TB.
Last edited by Tom400CFI; 04-17-2019 at 01:59 PM.
#19
Team Owner
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St. Jude Donor '05
how is paint going to knock 2/10 off the 1/4
#20
Le Mans Master
Depends on what you paint it with. You paint it with epoxy, you're basically putting a layer of plastic on the inside of a metal intake. GM didn't switch to plastic intakes to save money.