Heat Exchanger Air Duct

Desert Sasqwatch

Goblin Guru
Ark, if you look into the nose of the car you will see a gap between the side of the radiator and inside of the hood panel. I plan to research putting a duct in this gap, that will likely be a fiberglass piece on the inside of the hood, that will go past the radiator and port cool air to a heat exchanger mounted behind the radiator.

I too do not want to put NACA ducts into the side of hood in front of the suspension, I have other plans for this area (hint: downforce). Not sure how clear my explanation is, but I will post some stuff once I get it worked out. ;)
 

Christopher Sanchez

Well-Known Member
Does any body have air intake temp measurements with the naca duct and shroud setup? I need to decrease my intake temps, I took out the car this AM just realizing that the RPD displays air intake temps. Which is sweet! However I did not like what I saw. Under constant Hwy speeds 75-80 MPH. Temps would linger around 115-120! It cools off during stop and go traffic when out of boost. However during very spirited driving on some sweet curvy road temps with a few 1st- 3rd gear pulls temps would hit 150 with notable power being pulled by the PCM. Now I am not saying the car is running rough by any means just feel the power drop from 150 degree intake temps! yikes... Temps outside were low 80s which is nice for NM, the system is full of coolant fan is on anytime the key is on. I new this has been an issue that many choose to address with their cars just never saw the actual numbers. I am actually aware that the engine compartment area is essentially dead air which is not helping my intake temps. i am curious to see if the naca assembly brings down the temps "well enough" or if going air to air is the best way. thanks everyone!
 

Christopher Sanchez

Well-Known Member
I think these vents will help out quite a bit, but I think you're right though. I'm currently running the stock setup without body work, and my IAT2 temps can average anywhere from 30-35 degrees higher than ambient. There have been several times that I've gone for a drive with an 85 degree air temp, and the IAT2s are almost 110 degrees after I get home. That's with driving the last couple miles very leisurely. This could very well be normal as I really have no previous experience with IATs. Based on what I'm reading from other Cobalt owners, these numbers are a bit high.

I think having the intercooler sit right above the intake manifold has something to do with the the heat soak rate too. There is quite a bit of heat that transfers from the engine through the air and through the mounting brackets.
hey i know this is an old post but were you monitoring your air intake temps in real time with the original setup, Was the 110 reading after you have cruised it a bit or while you were getting on it? and also have you improved your set up since this post? Thanks
 

ctuinstra

Goblin Guru
150 is way too high in my opinion! During our dyno day, they chose to ignore the HE and the temps got to almost 160 and the car made a weird noise that he thought was pinging or knocking but none recorded. He couldn't figure it out until I ensisted that he put a fan on it. Sure enough as the car cooled back down, every thing was fine again.

Check out our HE set up. It may not be to everyone's liking but we have never had issues with high temps (other than dyno day where it's not moving air over it).
 

Tinkles

Well-Known Member
Does any body have air intake temp measurements with the naca duct and shroud setup? I need to decrease my intake temps, I took out the car this AM just realizing that the RPD displays air intake temps. Which is sweet! However I did not like what I saw. Under constant Hwy speeds 75-80 MPH. Temps would linger around 115-120! It cools off during stop and go traffic when out of boost. However during very spirited driving on some sweet curvy road temps with a few 1st- 3rd gear pulls temps would hit 150 with notable power being pulled by the PCM. Now I am not saying the car is running rough by any means just feel the power drop from 150 degree intake temps! yikes... Temps outside were low 80s which is nice for NM, the system is full of coolant fan is on anytime the key is on. I new this has been an issue that many choose to address with their cars just never saw the actual numbers. I am actually aware that the engine compartment area is essentially dead air which is not helping my intake temps. i am curious to see if the naca assembly brings down the temps "well enough" or if going air to air is the best way. thanks everyone!
From my experience with my supercharged Cavalier those temps are right in the normal window with an air to water IC system. There are a few things you can do to lower the temps.

1. Increase the amount of coolant/water in the system, the more there is, the longer it takes to heat up.
2. Add an ice box to the system that you can fill with ice to cool the coolant/water down. Downside is that it won't last too long.
3. Chemical cooling with water/methonal injection or nitrous. Water/meth injection can be done without a retune but you should be able to add a few more degrees of timing with it and pick up some more power, but you have to make sure that you don't run out.
 

George

Goblin Guru
From my experience with my supercharged Cavalier those temps are right in the normal window with an air to water IC system. There are a few things you can do to lower the temps.

1. Increase the amount of coolant/water in the system, the more there is, the longer it takes to heat up.
2. Add an ice box to the system that you can fill with ice to cool the coolant/water down. Downside is that it won't last too long.
3. Chemical cooling with water/methonal injection or nitrous. Water/meth injection can be done without a retune but you should be able to add a few more degrees of timing with it and pick up some more power, but you have to make sure that you don't run out.
I vote water injection and water spray nozzle on the heat exchanger. Been using water for the last 42 years.

Brad
 

Christopher Sanchez

Well-Known Member
150 is way too high in my opinion! During our dyno day, they chose to ignore the HE and the temps got to almost 160 and the car made a weird noise that he thought was pinging or knocking but none recorded. He couldn't figure it out until I ensisted that he put a fan on it. Sure enough as the car cooled back down, every thing was fine again.

Check out our HE set up. It may not be to everyone's liking but we have never had issues with high temps (other than dyno day where it's not moving air over it).
Was this the set up with naca ducts or a fan on the heat exchanger?... I agree it’s much to high however with the fan setup and positioning of the heat exchanger I can’t imagine it gets much air flow and relay primarily on the fan...
 

Christopher Sanchez

Well-Known Member
From my experience with my supercharged Cavalier those temps are right in the normal window with an air to water IC system. There are a few things you can do to lower the temps.

1. Increase the amount of coolant/water in the system, the more there is, the longer it takes to heat up.
2. Add an ice box to the system that you can fill with ice to cool the coolant/water down. Downside is that it won't last too long.
3. Chemical cooling with water/methonal injection or nitrous. Water/meth injection can be done without a retune but you should be able to add a few more degrees of timing with it and pick up some more power, but you have to make sure that you don't run out.
I have thought of option one and two but as others have pointed out to be increasing water capacity will increase the time it takes for the water to cool down once hot... this is a week end toy for me, drive 10-20 miles of hwy and back roads.
 

Ross

Goblin Guru
That would definitely be a fix.. curious if air to air would work better if I was to mount up top...
An air2air intercooler cools the air immediately and only has a small amount of thermal mass in the aluminum, so you need a bigger intercooler.
An water2air intercooler stores a lot of energy in the water, and keeps cooling down the water when you are off the throttle. My water gets about 10 degrees above ambient when I am getting on it, I don't know the intake air temps. It is small enough that I can look around it when I do a shoulder check for traffic... you probably can't do that with a big air2air in there.

Lots of pros and cons, and places to mount things. I am considering moving it lower, between the drivers seat and the fuse box area. Probably need to put the electric fan on it in that location.
 

Brian74

Goblin Guru
I started a polling thread discussion quite some time back for that; as it is a major concern of mine. Heat soak seems to be a threshold of no return based on the intake air cooling for a given ambient temp; especially during the summer. I know the guys running big A2A turbo intercoolers seem to have the best short term off throttle results. I am looking for a happy medium for those of us with both SC/TC using L2A. If you have the time, please post what facts/temps ect. you can in that thread I’d really appreciate it.

 
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Christopher Sanchez

Well-Known Member
An air2air intercooler cools the air immediately and only has a small amount of thermal mass in the aluminum, so you need a bigger intercooler.
An water2air intercooler stores a lot of energy in the water, and keeps cooling down the water when you are off the throttle. My water gets about 10 degrees above ambient when I am getting on it, I don't know the intake air temps. It is small enough that I can look around it when I do a shoulder check for traffic... you probably can't do that with a big air2air in there.

Lots of pros and cons, and places to mount things. I am considering moving it lower, between the drivers seat and the fuse box area. Probably need to put the electric fan on it in that location.
**** good point about the visibility concerns as I usually take a second and third glance over my shoulder when changing lanes in this little thing.. plus honestly I’d like to keep the roll bar clear for aesthetics...
 

Indy Lonnie

Well-Known Member
Does any body have air intake temp measurements with the naca duct and shroud setup? I need to decrease my intake temps, I took out the car this AM just realizing that the RPD displays air intake temps. Which is sweet! However I did not like what I saw. Under constant Hwy speeds 75-80 MPH. Temps would linger around 115-120! It cools off during stop and go traffic when out of boost. However during very spirited driving on some sweet curvy road temps with a few 1st- 3rd gear pulls temps would hit 150 with notable power being pulled by the PCM. Now I am not saying the car is running rough by any means just feel the power drop from 150 degree intake temps! yikes... Temps outside were low 80s which is nice for NM, the system is full of coolant fan is on anytime the key is on. I new this has been an issue that many choose to address with their cars just never saw the actual numbers. I am actually aware that the engine compartment area is essentially dead air which is not helping my intake temps. i am curious to see if the naca assembly brings down the temps "well enough" or if going air to air is the best way. thanks everyone!
The NACA duct kit works great. I am also not using the fan. I have it, but never installed it... I have been doing at least 50-100 miles per week since the COVID outbreak to pass time. Now realize my driving has been in temp between 60-70 degrees outside, but my IAT2s have never gotten above 100 for any length of time that I have noticed. Even after a 0-80 mph full throttle blast, it settles back down to within 15 degrees in under a minute. Once cruising, my IAT1 to IAT2 is within 12-13 degrees of each other. I have a Aeroforce Interceptor gauge and can monitor both IAT temps at the same time.
I spent some time and $ on the cold air intake and the NACA setup. Well worth the effort. The standard location of the air filter next to the firewall would heat soak and my IAT1 would gradually rise up 10-20+ degrees of ambient. Now after the cold intake, IAT1 stays within 2-3 degrees of ambient. Your intercooling is as good as its weakest link. A cold air intake with the NACA duct kit is working great for me. You do not need a bigger intercooler, you just have to get all the pieces you currently have to work together efficiently.
 

RouteAbel

Well-Known Member
The NACA duct kit works great. I am also not using the fan. I have it, but never installed it... I have been doing at least 50-100 miles per week since the COVID outbreak to pass time. Now realize my driving has been in temp between 60-70 degrees outside, but my IAT2s have never gotten above 100 for any length of time that I have noticed. Even after a 0-80 mph full throttle blast, it settles back down to within 15 degrees in under a minute. Once cruising, my IAT1 to IAT2 is within 12-13 degrees of each other. I have a Aeroforce Interceptor gauge and can monitor both IAT temps at the same time.
I spent some time and $ on the cold air intake and the NACA setup. Well worth the effort. The standard location of the air filter next to the firewall would heat soak and my IAT1 would gradually rise up 10-20+ degrees of ambient. Now after the cold intake, IAT1 stays within 2-3 degrees of ambient. Your intercooling is as good as its weakest link. A cold air intake with the NACA duct kit is working great for me. You do not need a bigger intercooler, you just have to get all the pieces you currently have to work together efficiently.
Can you explain more what you did with the cold air intake?
 

Briann1177

Goblin Guru
I relocated my intake right between the passenger tire and frame. I mainly did that to reduce the sucking noise and to get it out of the stock location thereby making it a bit more of a cooler air intake.
 
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