Hi Guys,
First I'd like to say thanks for those who helped me out with thermocouple post I made a few weeks ago. Looking into that has brought me to another project I would like to try.
A friend of mine has a turbo and intercooler on his car. He is curios to know how efficient the intercooler is at cooling down the intake air. I figure the way to do this is to have a sensor at both the inlet and outlet of the intercooler, than compare the two. He would like to have a readout that would show the temperature going in, temperature going out, and the difference between the two.
I have done some research on thermistors, but I have a few questions. Most of them have a temperature range that maxes at 125 degrees C. I'm not positive, but I have a feeling that the air coming out of the turbo charger will be hotter than that. Do you guys know of an cheap ($10 or less) sensors that I could use for this? I was thinking of just going to an auto parts store to see what they have for cheap intake air sensors. However, I think it'll be very hard to find any specs on them; sure I could get a reading from them, but how would I interpret them. Also, if I do use a standard thermistor, how do I calibrate it to know what a temperature is for a given resistance?
I'm thinking that I'll use a PIC MCU with a 16x2 or similer LCD display with a backlight. Once I get the sensor reading figured out the rest should be pretty straightforward, eh?
Thanks,
Craig
Measuring temperature drop from an intercooler
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Chris Smith
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You don’t measure the temperature coming out of the Turbo outlet, you measure the air coming into the intercooler, then measure the drop in temperatures as it leaves the intercooler,.....before it gets to the turbo.
That is its efficiency.
X gpm flow of air times temperature drop.
The turbo compresses fresh cooler air from the intercooler, which then raises back some of the air’s cooler temperature [compression] before mixing with the fuel,...... so that the intercooler off sets some of this temperature rise before being mixed and charged for the cylinder.
That is its efficiency.
X gpm flow of air times temperature drop.
The turbo compresses fresh cooler air from the intercooler, which then raises back some of the air’s cooler temperature [compression] before mixing with the fuel,...... so that the intercooler off sets some of this temperature rise before being mixed and charged for the cylinder.
The air goes from the turbo to the intercooler then into the intake manifold via the throttle body. The air gets heated up by the turbo because the turbo is driven by the exhaust gas. The hot air then goes through the intercooler to cool down before it gets pushed into the engine.
I'm not trying to measure the efficiency of the the flow of air through the intercooler (although that would be interesting to find out), I just need to measure the temperature drop of the air as it goes through the intercooler.
What do I need to look for from a thermistor that will measure up to about (I'm guessing) 200 degrees C? The local electronics store has lots of thermistors, but they don't have any specs on them at all. If I find one online somewhere, do they all have standard codes? Could I write down the code for the one I see online and find one with the same code in the store? (Sort of like how IC's have standard codes).
I'm not trying to measure the efficiency of the the flow of air through the intercooler (although that would be interesting to find out), I just need to measure the temperature drop of the air as it goes through the intercooler.
What do I need to look for from a thermistor that will measure up to about (I'm guessing) 200 degrees C? The local electronics store has lots of thermistors, but they don't have any specs on them at all. If I find one online somewhere, do they all have standard codes? Could I write down the code for the one I see online and find one with the same code in the store? (Sort of like how IC's have standard codes).
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Chris Smith
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- Joined: Tue Dec 04, 2001 1:01 am
- Location: Bieber Ca.
Your still mistaken, the AIR is cooled by the intercooler so that when the TURBO pressurizes the air, it is hotter. [X= loss+ gain]
The intercooler lowers this heat efficiency,...before the fact.
You can not measure the turbo as that is a function of pumped air pressure and exhaust heat depending on speed and time.
You can not determine that the turbo adds heat simply because its near the exhaust
[obvious depending on speed]
These are efficiencies, or losses, depending on how good they work. [time, pressure, speed, incline, etc]
You need to find the air flow efficiency of the intercooler, not the transfer ratio of the turbo’s heat which will change by the second.
[heat from manifold not included]
The intercooler lowers this heat efficiency,...before the fact.
You can not measure the turbo as that is a function of pumped air pressure and exhaust heat depending on speed and time.
You can not determine that the turbo adds heat simply because its near the exhaust
[obvious depending on speed]
These are efficiencies, or losses, depending on how good they work. [time, pressure, speed, incline, etc]
You need to find the air flow efficiency of the intercooler, not the transfer ratio of the turbo’s heat which will change by the second.
[heat from manifold not included]
Chris, are you trying to tell me that the intake air goes through the intercooler first, THEN through the turbo, then into the intake manifold That makes no sense.
The air flow on a turbo charged and intercooled vehicle goes like this:
Environment > Air Filter > Turbo > Intercooler > Throttle Body > Intake Manifold > Combustian Chamber.
You're right about where the heat comes from, it's the pressure that makes it hot, not the heat from the exhaust.
I think either you're over complicating things, I don't understand what you're trying to say, or maybe I'm trying to measure something that just isn't practical. Are you saying that the temperature of the air coming out of the turbo will constantly change depending on the pressure involved? If so, do you think that the temperature would change so quickly that it's just not practical or useful to monitor? Maybe a quick response analog gauge would be best?
Again, I don't want to measure the air flow efficiency of the intercooler, just how well it cools the air. If the temperature of the air will change so dramatically depending on the pressure, do you think it would make sense to only measure the difference in temperature, rather than the temperature itself?
jwax, I thought about thermocouples, but they can be expensive and complicated to set up. Using thermocouple requieres a cold junction compensater. Many measuring devices have that built in, but they aren't cheap! Is it really that difficult to use PIC or something similer to meaure current?
The air flow on a turbo charged and intercooled vehicle goes like this:
Environment > Air Filter > Turbo > Intercooler > Throttle Body > Intake Manifold > Combustian Chamber.
You're right about where the heat comes from, it's the pressure that makes it hot, not the heat from the exhaust.
I think either you're over complicating things, I don't understand what you're trying to say, or maybe I'm trying to measure something that just isn't practical. Are you saying that the temperature of the air coming out of the turbo will constantly change depending on the pressure involved? If so, do you think that the temperature would change so quickly that it's just not practical or useful to monitor? Maybe a quick response analog gauge would be best?
Again, I don't want to measure the air flow efficiency of the intercooler, just how well it cools the air. If the temperature of the air will change so dramatically depending on the pressure, do you think it would make sense to only measure the difference in temperature, rather than the temperature itself?
jwax, I thought about thermocouples, but they can be expensive and complicated to set up. Using thermocouple requieres a cold junction compensater. Many measuring devices have that built in, but they aren't cheap! Is it really that difficult to use PIC or something similer to meaure current?
Craig...
Take a look at this page
http://www.gnttype.org/techarea/turbo/intercooler.html
This guy goes throiugh the temperature differential math and may contain a lot that isn't of interest to you. However, he ran some tests measuring inlet/outlet temperatures and set up his system using thermocouples. There may be an idea or two in there for you.
Wally
Take a look at this page
http://www.gnttype.org/techarea/turbo/intercooler.html
This guy goes throiugh the temperature differential math and may contain a lot that isn't of interest to you. However, he ran some tests measuring inlet/outlet temperatures and set up his system using thermocouples. There may be an idea or two in there for you.
Wally
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Michael Kaudze
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http://www.blitz-performance.com/Blitz_ ... ler_LM.htm
Getting this for my car next month!
"Each BLITZ® Intercooler Kit is individually design for each vehicle produce maximum efficiency and performance. All BLITZ® intercooler kits come complete with aluminum piping and all the necessary hardware.
Intercoolers provide more power and reliability to any turbocharged vehicle. Intercoolers are heat exchangers, which are used to quickly cool down and dissipate the heat from the intake charge. During intense driving, the turbo compressor wheel super-heats. As a result, compressed air is forced through the turbochargers. Super-heated air reduces the density of the charge air, increasing the chance of detonation and reducing the power output of the vehicle. BLITZ® intercoolers are designed to give maximum cooling capacity while allowing for minimal pressure drop. This is especially important if boost pressure is being raised, greatly reducing the chance of detonation. BLITZ® intercoolers has the been known as the most efficient intercooler with a pressure drop of .05kg/cm2 at 1.2kg/cm2 of boost.
BLITZ® intercoolers are designed to flow considerably more amount of air than the stock intercooler by consistently and rapidly drawing away heat. With its tube and fin design a much greater cooling effect is achieved. A cooler airflow intake means a more dense charge of air, which in turn creates more horsepower. This reduces thermal stress to the turbocharger components and produces gains throughout the power hand."
Getting this for my car next month!
"Each BLITZ® Intercooler Kit is individually design for each vehicle produce maximum efficiency and performance. All BLITZ® intercooler kits come complete with aluminum piping and all the necessary hardware.
Intercoolers provide more power and reliability to any turbocharged vehicle. Intercoolers are heat exchangers, which are used to quickly cool down and dissipate the heat from the intake charge. During intense driving, the turbo compressor wheel super-heats. As a result, compressed air is forced through the turbochargers. Super-heated air reduces the density of the charge air, increasing the chance of detonation and reducing the power output of the vehicle. BLITZ® intercoolers are designed to give maximum cooling capacity while allowing for minimal pressure drop. This is especially important if boost pressure is being raised, greatly reducing the chance of detonation. BLITZ® intercoolers has the been known as the most efficient intercooler with a pressure drop of .05kg/cm2 at 1.2kg/cm2 of boost.
BLITZ® intercoolers are designed to flow considerably more amount of air than the stock intercooler by consistently and rapidly drawing away heat. With its tube and fin design a much greater cooling effect is achieved. A cooler airflow intake means a more dense charge of air, which in turn creates more horsepower. This reduces thermal stress to the turbocharger components and produces gains throughout the power hand."
Wally, Holy Crap that's a lot of information!! Why can't life be simple?
I'll print it out and read it, thanks!
Michael, what kind of car do you have? My buddy who I'm doing this project for has a Dodge Omni GLH Turbo, which is heavily modified. Last hear his best 1/4 mile time was 12.2. This year will be all about tuning I think.
I'll print it out and read it, thanks!
Michael, what kind of car do you have? My buddy who I'm doing this project for has a Dodge Omni GLH Turbo, which is heavily modified. Last hear his best 1/4 mile time was 12.2. This year will be all about tuning I think.
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Michael Kaudze
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currently I have a 2004 Subaru WRX. Not too many mod's but I am starting to build her up...
Currently:
Blitz Nur Spec Racing Exhaust
TurboXS Up-Pipe
TurboXS Downpipe
Exedy Stage 2 Organic Clutch
Gruppe Light Weight Flywheel
HKS SSQ Blow Off Valve
Plus some electronics....
Next month:
Perrin Turbo GT3071R Kit
Blitz FMIC
After I get it tuned, i should expect to see 300 to 400hp at the wheels.. I will let you know what my 1/4 and AutoX times are in a couple months.
Currently:
Blitz Nur Spec Racing Exhaust
TurboXS Up-Pipe
TurboXS Downpipe
Exedy Stage 2 Organic Clutch
Gruppe Light Weight Flywheel
HKS SSQ Blow Off Valve
Plus some electronics....
Next month:
Perrin Turbo GT3071R Kit
Blitz FMIC
After I get it tuned, i should expect to see 300 to 400hp at the wheels.. I will let you know what my 1/4 and AutoX times are in a couple months.
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Michael Kaudze
- Site Admin
- Posts: 16300
- Joined: Fri Nov 22, 2002 1:01 am
- Location: at work
- Contact:
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Chris Smith
- Posts: 4325
- Joined: Tue Dec 04, 2001 1:01 am
- Location: Bieber Ca.
All of the turbo intercoolers I have worked are in the grill cooling down the incoming air, but that isn’t the point.
Your trying to measure the turbo via the intercooler, that’s irrelevant.
You mention Intercooler efficiency.
The turbos heat is a set of numbers on its own, based on other factors.
You measure the intake of the intercooler VS the exhaust of the intercooler, be it before or after the turbo as you looking for efficience of the intercooler working, not how much the turbo it self will raise temperature depending on load or speed.
The intercooler is simply a “efficiencyâ€
Your trying to measure the turbo via the intercooler, that’s irrelevant.
You mention Intercooler efficiency.
The turbos heat is a set of numbers on its own, based on other factors.
You measure the intake of the intercooler VS the exhaust of the intercooler, be it before or after the turbo as you looking for efficience of the intercooler working, not how much the turbo it self will raise temperature depending on load or speed.
The intercooler is simply a “efficiencyâ€
That is NOT what I am trying to measure. Really, the existance of a turbo is irrelevant for what I want to measure.Your trying to measure the turbo via the intercooler, that’s irrelevant
Yes, that is what I am trying to measure.You measure the intake of the intercooler VS the exhaust of the intercooler
Anyways, I'm not interested in discussing the theory of how an turbo/intercooler system works and how or why cooler air is better, that's for another forum.
All of the above aside, put simply, if I want to measure the air temperature which will be in the range of 100 - 200 degrees (or more), would standard thermistors work, and if so, how should I track one down that work work in that range?
I realize that thermistors measure current rather than voltage, but couldn't I setup a little circuit where the voltage through it would change depending on the resistive value of the thermistor?
Craig,
Have you thought of just using a plain old resistor as the temperature sensing element? Considering the vast variations in air temperature, it out to do just fine. Resistance inscreases with temperature. EDIT: I take this back. Plain resistors are manufactured to minimize resistance change with temperature. Mr. Hayes has a better idea (below).
My son Theo has a V6 GTI with European body kit and a belt driven supercharger from Z Engineering (Swiss). No intercooler.
If you are interested:
http://picasaweb.google.ca/TRJScott/GTIVR6DE
Specifications say it has a mild 0.55 bar pressure boost at full output.
Remembering that PV=nrT from my high school physics/chemistry, and considering outside air and pressure at STP (1 bar and 293 degrees Kelvin), I figure it compresses the air to 80% of original volume and the temperature rises by 125% after the supercharger.
Post compression air temp is 366 K, or 93 C or 200 F. If Theo would add an intercooler it would drop the compressed air temp back down close to 20 C and volume would go down another 20%.
Unfortunately, as you can see if you look at the above link, there is not much room for an intercooler.
Bob
Have you thought of just using a plain old resistor as the temperature sensing element? Considering the vast variations in air temperature, it out to do just fine. Resistance inscreases with temperature. EDIT: I take this back. Plain resistors are manufactured to minimize resistance change with temperature. Mr. Hayes has a better idea (below).
My son Theo has a V6 GTI with European body kit and a belt driven supercharger from Z Engineering (Swiss). No intercooler.
If you are interested:
http://picasaweb.google.ca/TRJScott/GTIVR6DE
Specifications say it has a mild 0.55 bar pressure boost at full output.
Remembering that PV=nrT from my high school physics/chemistry, and considering outside air and pressure at STP (1 bar and 293 degrees Kelvin), I figure it compresses the air to 80% of original volume and the temperature rises by 125% after the supercharger.
Post compression air temp is 366 K, or 93 C or 200 F. If Theo would add an intercooler it would drop the compressed air temp back down close to 20 C and volume would go down another 20%.
Unfortunately, as you can see if you look at the above link, there is not much room for an intercooler.
Bob
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