Intecooler continued :)
05-19-2006, 11:16 PM
#1
4th Gear Member
Thread Starter
Join Date: Sep 2005
Location:
Posts: 1,144
Intecooler continued :)
Hey scrming I think we are hi jacking that other thread sorry guys.
Scrming that was a good definition you posted.
The thing is why do Procharger and Powerhouse call it a intercooler? I like to hear thier explantion maybe there is a reason.
Also here is a prime example of someone calling it an IC, but the real thing and reason I posted this is I want you to read in this article remember when YKW said and keep claiming intercooler produces higher boost well according to this it does NOT increase but decreases boost.
Overview: Intercoolers and the 22R-TE
An intercooler, for those who don't know, is essentially a radiator designed to cool the hot "boosted" air coming out of the turbocharger. Because compressing air raises its temperature (generally around 150 degrees F above ambient air temperature for every 7 psi of boost), intercooling goes hand in hand with turbocharging . Since the stock boost in the 22R-TE is about 7 psi, this means that the temperature of the stock system's output (on a 70 degree spring day) would be something like 220 degrees F. Raise the boost to 14 psi, and you're looking at 370 degrees F when the air reaches the injectors; not only does this heat prevent your engine from reaching its performance potential, the hot air expands the fuel mixture, leading to detonation and poor mileage.
Enter the intercooler. Intercoolers can create dramatic results on engines that run a lot of boost, because this excess heat has a place to dissipate. But how much of a difference can an intercooler make on a stock 22R-TE?
From my experience, I'd have to say that an intercooler *by itself* does not yield a significant increase in performance on a 22R-TE running stock boost. This is mostly because the stock boost is so low, but it's also because an intercooler introduces some additional turbo lag, and the stock setup already has enough of that courtesy of its design.
Before the addition of the intercooler, I was seeing 7.5 psi of boost at the throttle plate (where my boost gauge takes its reading from). This is on the high end of the stock boost spectrum. After adding an intercooler, this figure dropped to 6 psi. Performance remained about the same: whatever gains I saw from cooling the intake charge were likely mitigated by the (comparatively significant) drop in boost pressure. In other words, it was basically a wash. An intercooler alone was not a big power maker on my ride.
[Note: Brian W. has pointed out to me that this pressure drop is also due to the cooling effects of the intercooler: cooler air is denser, so simple physics would indicate that for a given boost, cooler air will always take up less volume than warmer air; hence the pressre drop I saw. Thanks, Brian...for making me realize anew why I got a C in Physics :-)]
Running 13 psi of boost, I saw *SIGNIFICANT* gains in the vehicle's performance: It screamed! It put a huge smile on my face. It said, "This is why people turbocharge things in the first place." With the added boost, the installation of the intercooler made more sense, because there was now a lot of excess heat to control, and enough boost to compensate for the loss in pressure caused by the presence of the intercooler in the intake stream.
Scrming did you decide your going with a S/C?
Scrming that was a good definition you posted.
The thing is why do Procharger and Powerhouse call it a intercooler? I like to hear thier explantion maybe there is a reason.
Also here is a prime example of someone calling it an IC, but the real thing and reason I posted this is I want you to read in this article remember when YKW said and keep claiming intercooler produces higher boost well according to this it does NOT increase but decreases boost.
Overview: Intercoolers and the 22R-TE
An intercooler, for those who don't know, is essentially a radiator designed to cool the hot "boosted" air coming out of the turbocharger. Because compressing air raises its temperature (generally around 150 degrees F above ambient air temperature for every 7 psi of boost), intercooling goes hand in hand with turbocharging . Since the stock boost in the 22R-TE is about 7 psi, this means that the temperature of the stock system's output (on a 70 degree spring day) would be something like 220 degrees F. Raise the boost to 14 psi, and you're looking at 370 degrees F when the air reaches the injectors; not only does this heat prevent your engine from reaching its performance potential, the hot air expands the fuel mixture, leading to detonation and poor mileage.
Enter the intercooler. Intercoolers can create dramatic results on engines that run a lot of boost, because this excess heat has a place to dissipate. But how much of a difference can an intercooler make on a stock 22R-TE?
From my experience, I'd have to say that an intercooler *by itself* does not yield a significant increase in performance on a 22R-TE running stock boost. This is mostly because the stock boost is so low, but it's also because an intercooler introduces some additional turbo lag, and the stock setup already has enough of that courtesy of its design.
Before the addition of the intercooler, I was seeing 7.5 psi of boost at the throttle plate (where my boost gauge takes its reading from). This is on the high end of the stock boost spectrum. After adding an intercooler, this figure dropped to 6 psi. Performance remained about the same: whatever gains I saw from cooling the intake charge were likely mitigated by the (comparatively significant) drop in boost pressure. In other words, it was basically a wash. An intercooler alone was not a big power maker on my ride.
[Note: Brian W. has pointed out to me that this pressure drop is also due to the cooling effects of the intercooler: cooler air is denser, so simple physics would indicate that for a given boost, cooler air will always take up less volume than warmer air; hence the pressre drop I saw. Thanks, Brian...for making me realize anew why I got a C in Physics :-)]
Running 13 psi of boost, I saw *SIGNIFICANT* gains in the vehicle's performance: It screamed! It put a huge smile on my face. It said, "This is why people turbocharge things in the first place." With the added boost, the installation of the intercooler made more sense, because there was now a lot of excess heat to control, and enough boost to compensate for the loss in pressure caused by the presence of the intercooler in the intake stream.
Scrming did you decide your going with a S/C?
05-20-2006, 02:45 AM
#2
I ♥ Acer
Join Date: May 2006
Location:
Posts: 184
RE: Intecooler continued :)
The main theory behind the intercooler is the first law of thermodynamics. In this application, Work is equal to the mass air flow times the thermal capacity of air times the change in temperature or mass air flow times the change in enthalpy. The key term being the mass air flow, wich is the volumetric flow rate of the air (CFM) times density. The ideal gas law shows that at a constant pressure as the temperature decreases, the density increases. Since your blower should be keeping the air at a "constant" pressure, the intercooler makes the air more dense, increases the mass air flow, and in return increases the work, or horse power. Your main loss in pressure with an intercooler is the static pressure across the coils, but the blower should have enough static pressure to overcome this loss if designed correctly. Basically the blower puts out a higher pressure at the discharge so that after all the losses, you should be getting your psi boost that you see at the throttle body. The cooling of the air should help your horse power with a super charger, but to run it by itself, the pressure loss through the coils would most likely drop the pressure at the throttle body to much and would decrease performance.
05-20-2006, 03:47 AM
#3
4th Gear Member
Join Date: Apr 2006
Location:
Posts: 1,268
RE: Intecooler continued :)
Because a turbocompressor is an "open" system, a simple 1st law analysis is not complete. A mechanical energy balance has to be used. Compressing a gas in a turbocharger is essentially an adiabatic compression process. An adiabatic process is one where little heat is transfered into or out of the gas during the actual compression step. In a turbocharger, the gas is compressed so quickly, and spends such a little bit of time in the compressor, that essentially no heat is added or removed. Hence, it is an adiabatic process.
For adiabatic processes, there is an equation that relates the inlet temperature and pressure of a gas, and the outlet temperature and pressure of a gas. The equation is
T_out = T_in x (P_out/P_in)^0.286
So, if we have a gas entering the turbocharger at 70 degrees F and 1 atmosphere, or about 14.7 psi, then we can apply this equation to determine the outlet temperature if the pressure rise, or boost is known.
Now, the Temperature must be expressed as an absolute temperature (farenheit is not an absolute temperature scale) so we must use Kelvin or Rankine temperature. Lets use Rankine...
T (Rankine) = T (Fahrenheit) + 460
So, our equation becomes
T_out (in F) = (T_in + 460) x (P_out/P_in)^0.286 - 460
So, for 70 degree in, 1 atmosphere, and 9 psi boost or 1.61 atmospheres outlet P we get
T_out (in F) = (70 + 460) x (1.61/1.0)^0.286 - 460
T_out (in F) = 530 x (1.61)^0.286 - 460
T_out (in F) = 530 x 1.145 - 460
T_out (in F) = 148 degrees, or a 78 degree F temperature rise
For 12 psi of boost, the exiting temperature is almost 186 degree F !!
Now... in engineering terms, an intercooler is a heat exchanger that removes heat from a stream BETWEEN stages of compression... so if you had one turbo compress the gas 6 psi and then you cooled it, and then the gas entered a second compressor to be compressed from 6 psi to 12 psi, then this heat exchanger is an INTERcooler..... the cooler is INTERstage. If the gas is compressed in a single stage, and then cooled before being passed onto the next piece of processing equipment (in this case the engine), then the heat exchanger is an AFTERcooler. You can also have a train with an intercooler and an aftercooler.... i.e. turbo->intercooler->turbo->aftercooler.
also note
"[Note: Brian W. has pointed out to me that this pressure drop is also due to the cooling effects of the intercooler: cooler air is denser, so simple physics would indicate that for a given boost, cooler air will always take up less volume than warmer air; hence the pressre drop I saw. Thanks, Brian...for making me realize anew why I got a C in Physics :-)] "
This is not the case. In a continuous open flowing system, the simple "higher temperature means less dense, lower temperature means more dense" does not apply. This is for closed systems. The pressure drop you saw was because the additional piping to and from the intercooler, and the intercooler itself introduced a pressure drop in the flowing system....thus the pressure you saw AT the engine was lower, but the gas was cooler.... so where is the balance?
Well, if the gas pressure fell from (14.7+7.5=22.2psi) to (14.7+6=20.7psi) then the DENSITY of the air fell by the ratio of 20.7/22.2 or the air with the aftercooler was 93% as dense as the original air.... BUTTTTTTTT.... the air is now COOLER because of the intercooler, and thus is more dense... how much more dense? Well if the NON-intercooled air is about 150 degree F or 610 degree Rankine, and the intercooled air is 80 degree F or 540 degree Rankine, then the air is 610/540 or 13% more dense. Thus, the net effect is a +6% (-7% due to pressure lower and +13% due to lower temp) increase in O2 molecules entering the system in an intercooled system.... giving you 6% more power in the intercooled system... if your boost is higher, you get even more benefit from intercooling, doubling to over 10% or more.
All this is theoretical of course. No account for compressor efficiency, or pressure drop through piping or slight heat leak during compression etc.
For adiabatic processes, there is an equation that relates the inlet temperature and pressure of a gas, and the outlet temperature and pressure of a gas. The equation is
T_out = T_in x (P_out/P_in)^0.286
So, if we have a gas entering the turbocharger at 70 degrees F and 1 atmosphere, or about 14.7 psi, then we can apply this equation to determine the outlet temperature if the pressure rise, or boost is known.
Now, the Temperature must be expressed as an absolute temperature (farenheit is not an absolute temperature scale) so we must use Kelvin or Rankine temperature. Lets use Rankine...
T (Rankine) = T (Fahrenheit) + 460
So, our equation becomes
T_out (in F) = (T_in + 460) x (P_out/P_in)^0.286 - 460
So, for 70 degree in, 1 atmosphere, and 9 psi boost or 1.61 atmospheres outlet P we get
T_out (in F) = (70 + 460) x (1.61/1.0)^0.286 - 460
T_out (in F) = 530 x (1.61)^0.286 - 460
T_out (in F) = 530 x 1.145 - 460
T_out (in F) = 148 degrees, or a 78 degree F temperature rise
For 12 psi of boost, the exiting temperature is almost 186 degree F !!
Now... in engineering terms, an intercooler is a heat exchanger that removes heat from a stream BETWEEN stages of compression... so if you had one turbo compress the gas 6 psi and then you cooled it, and then the gas entered a second compressor to be compressed from 6 psi to 12 psi, then this heat exchanger is an INTERcooler..... the cooler is INTERstage. If the gas is compressed in a single stage, and then cooled before being passed onto the next piece of processing equipment (in this case the engine), then the heat exchanger is an AFTERcooler. You can also have a train with an intercooler and an aftercooler.... i.e. turbo->intercooler->turbo->aftercooler.
also note
"[Note: Brian W. has pointed out to me that this pressure drop is also due to the cooling effects of the intercooler: cooler air is denser, so simple physics would indicate that for a given boost, cooler air will always take up less volume than warmer air; hence the pressre drop I saw. Thanks, Brian...for making me realize anew why I got a C in Physics :-)] "
This is not the case. In a continuous open flowing system, the simple "higher temperature means less dense, lower temperature means more dense" does not apply. This is for closed systems. The pressure drop you saw was because the additional piping to and from the intercooler, and the intercooler itself introduced a pressure drop in the flowing system....thus the pressure you saw AT the engine was lower, but the gas was cooler.... so where is the balance?
Well, if the gas pressure fell from (14.7+7.5=22.2psi) to (14.7+6=20.7psi) then the DENSITY of the air fell by the ratio of 20.7/22.2 or the air with the aftercooler was 93% as dense as the original air.... BUTTTTTTTT.... the air is now COOLER because of the intercooler, and thus is more dense... how much more dense? Well if the NON-intercooled air is about 150 degree F or 610 degree Rankine, and the intercooled air is 80 degree F or 540 degree Rankine, then the air is 610/540 or 13% more dense. Thus, the net effect is a +6% (-7% due to pressure lower and +13% due to lower temp) increase in O2 molecules entering the system in an intercooled system.... giving you 6% more power in the intercooled system... if your boost is higher, you get even more benefit from intercooling, doubling to over 10% or more.
All this is theoretical of course. No account for compressor efficiency, or pressure drop through piping or slight heat leak during compression etc.
05-20-2006, 03:49 PM
#5
I ♥ Acer
Join Date: May 2006
Location:
Posts: 184
RE: Intecooler continued :)
very nice, thanks for taking the time to do what I didn't want to...I was trying to keep in simple since most people don't understand enthalpy and entropy, etc..
For some reason I had a brain cramp about what an intercooler is....I was sitting here reading it and knew it was between compresson stages....they are used in industrial multi stage air compressors, but I was talking about an aftercooler.
For some reason I had a brain cramp about what an intercooler is....I was sitting here reading it and knew it was between compresson stages....they are used in industrial multi stage air compressors, but I was talking about an aftercooler.
ORIGINAL: LX200
Because a turbocompressor is an "open" system, a simple 1st law analysis is not complete. A mechanical energy balance has to be used. Compressing a gas in a turbocharger is essentially an adiabatic compression process. An adiabatic process is one where little heat is transfered into or out of the gas during the actual compression step. In a turbocharger, the gas is compressed so quickly, and spends such a little bit of time in the compressor, that essentially no heat is added or removed. Hence, it is an adiabatic process.
For adiabatic processes, there is an equation that relates the inlet temperature and pressure of a gas, and the outlet temperature and pressure of a gas. The equation is
T_out = T_in x (P_out/P_in)^0.286
So, if we have a gas entering the turbocharger at 70 degrees F and 1 atmosphere, or about 14.7 psi, then we can apply this equation to determine the outlet temperature if the pressure rise, or boost is known.
Now, the Temperature must be expressed as an absolute temperature (farenheit is not an absolute temperature scale) so we must use Kelvin or Rankine temperature. Lets use Rankine...
T (Rankine) = T (Fahrenheit) + 460
So, our equation becomes
T_out (in F) = (T_in + 460) x (P_out/P_in)^0.286 - 460
So, for 70 degree in, 1 atmosphere, and 9 psi boost or 1.61 atmospheres outlet P we get
T_out (in F) = (70 + 460) x (1.61/1.0)^0.286 - 460
T_out (in F) = 530 x (1.61)^0.286 - 460
T_out (in F) = 530 x 1.145 - 460
T_out (in F) = 148 degrees, or a 78 degree F temperature rise
For 12 psi of boost, the exiting temperature is almost 186 degree F !!
Now... in engineering terms, an intercooler is a heat exchanger that removes heat from a stream BETWEEN stages of compression... so if you had one turbo compress the gas 6 psi and then you cooled it, and then the gas entered a second compressor to be compressed from 6 psi to 12 psi, then this heat exchanger is an INTERcooler..... the cooler is INTERstage. If the gas is compressed in a single stage, and then cooled before being passed onto the next piece of processing equipment (in this case the engine), then the heat exchanger is an AFTERcooler. You can also have a train with an intercooler and an aftercooler.... i.e. turbo->intercooler->turbo->aftercooler.
also note
"[Note: Brian W. has pointed out to me that this pressure drop is also due to the cooling effects of the intercooler: cooler air is denser, so simple physics would indicate that for a given boost, cooler air will always take up less volume than warmer air; hence the pressre drop I saw. Thanks, Brian...for making me realize anew why I got a C in Physics :-)] "
This is not the case. In a continuous open flowing system, the simple "higher temperature means less dense, lower temperature means more dense" does not apply. This is for closed systems. The pressure drop you saw was because the additional piping to and from the intercooler, and the intercooler itself introduced a pressure drop in the flowing system....thus the pressure you saw AT the engine was lower, but the gas was cooler.... so where is the balance?
Well, if the gas pressure fell from (14.7+7.5=22.2psi) to (14.7+6=20.7psi) then the DENSITY of the air fell by the ratio of 20.7/22.2 or the air with the aftercooler was 93% as dense as the original air.... BUTTTTTTTT.... the air is now COOLER because of the intercooler, and thus is more dense... how much more dense? Well if the NON-intercooled air is about 150 degree F or 610 degree Rankine, and the intercooled air is 80 degree F or 540 degree Rankine, then the air is 610/540 or 13% more dense. Thus, the net effect is a +6% (-7% due to pressure lower and +13% due to lower temp) increase in O2 molecules entering the system in an intercooled system.... giving you 6% more power in the intercooled system... if your boost is higher, you get even more benefit from intercooling, doubling to over 10% or more.
All this is theoretical of course. No account for compressor efficiency, or pressure drop through piping or slight heat leak during compression etc.
Because a turbocompressor is an "open" system, a simple 1st law analysis is not complete. A mechanical energy balance has to be used. Compressing a gas in a turbocharger is essentially an adiabatic compression process. An adiabatic process is one where little heat is transfered into or out of the gas during the actual compression step. In a turbocharger, the gas is compressed so quickly, and spends such a little bit of time in the compressor, that essentially no heat is added or removed. Hence, it is an adiabatic process.
For adiabatic processes, there is an equation that relates the inlet temperature and pressure of a gas, and the outlet temperature and pressure of a gas. The equation is
T_out = T_in x (P_out/P_in)^0.286
So, if we have a gas entering the turbocharger at 70 degrees F and 1 atmosphere, or about 14.7 psi, then we can apply this equation to determine the outlet temperature if the pressure rise, or boost is known.
Now, the Temperature must be expressed as an absolute temperature (farenheit is not an absolute temperature scale) so we must use Kelvin or Rankine temperature. Lets use Rankine...
T (Rankine) = T (Fahrenheit) + 460
So, our equation becomes
T_out (in F) = (T_in + 460) x (P_out/P_in)^0.286 - 460
So, for 70 degree in, 1 atmosphere, and 9 psi boost or 1.61 atmospheres outlet P we get
T_out (in F) = (70 + 460) x (1.61/1.0)^0.286 - 460
T_out (in F) = 530 x (1.61)^0.286 - 460
T_out (in F) = 530 x 1.145 - 460
T_out (in F) = 148 degrees, or a 78 degree F temperature rise
For 12 psi of boost, the exiting temperature is almost 186 degree F !!
Now... in engineering terms, an intercooler is a heat exchanger that removes heat from a stream BETWEEN stages of compression... so if you had one turbo compress the gas 6 psi and then you cooled it, and then the gas entered a second compressor to be compressed from 6 psi to 12 psi, then this heat exchanger is an INTERcooler..... the cooler is INTERstage. If the gas is compressed in a single stage, and then cooled before being passed onto the next piece of processing equipment (in this case the engine), then the heat exchanger is an AFTERcooler. You can also have a train with an intercooler and an aftercooler.... i.e. turbo->intercooler->turbo->aftercooler.
also note
"[Note: Brian W. has pointed out to me that this pressure drop is also due to the cooling effects of the intercooler: cooler air is denser, so simple physics would indicate that for a given boost, cooler air will always take up less volume than warmer air; hence the pressre drop I saw. Thanks, Brian...for making me realize anew why I got a C in Physics :-)] "
This is not the case. In a continuous open flowing system, the simple "higher temperature means less dense, lower temperature means more dense" does not apply. This is for closed systems. The pressure drop you saw was because the additional piping to and from the intercooler, and the intercooler itself introduced a pressure drop in the flowing system....thus the pressure you saw AT the engine was lower, but the gas was cooler.... so where is the balance?
Well, if the gas pressure fell from (14.7+7.5=22.2psi) to (14.7+6=20.7psi) then the DENSITY of the air fell by the ratio of 20.7/22.2 or the air with the aftercooler was 93% as dense as the original air.... BUTTTTTTTT.... the air is now COOLER because of the intercooler, and thus is more dense... how much more dense? Well if the NON-intercooled air is about 150 degree F or 610 degree Rankine, and the intercooled air is 80 degree F or 540 degree Rankine, then the air is 610/540 or 13% more dense. Thus, the net effect is a +6% (-7% due to pressure lower and +13% due to lower temp) increase in O2 molecules entering the system in an intercooled system.... giving you 6% more power in the intercooled system... if your boost is higher, you get even more benefit from intercooling, doubling to over 10% or more.
All this is theoretical of course. No account for compressor efficiency, or pressure drop through piping or slight heat leak during compression etc.
05-20-2006, 05:28 PM
#6
RE: Intecooler continued :)
A (somewhat cheesy) case could be made for the term intercooler. An "intercooler" on an internal combustion engine typically resides between the supercharger where the air is compressed, and the engine's cylinders where it is further compressed along with fuel prior to ignition... So as a technicality as least, it is between two compression stages. 
05-20-2006, 06:09 PM
#7
I ♥ Acer
Join Date: Jun 2005
Location:
Posts: 766
RE: Intecooler continued :)
ORIGINAL: Torch_Vert
A (somewhat cheesy) case could be made for the term intercooler. An "intercooler" on an internal combustion engine typically resides between the supercharger where the air is compressed, and the engine's cylinders where it is further compressed along with fuel prior to ignition... So as a technicality as least, it is between two compression stages.
A (somewhat cheesy) case could be made for the term intercooler. An "intercooler" on an internal combustion engine typically resides between the supercharger where the air is compressed, and the engine's cylinders where it is further compressed along with fuel prior to ignition... So as a technicality as least, it is between two compression stages.
05-20-2006, 06:56 PM
#8
4th Gear Member
Join Date: Feb 2006
Location:
Posts: 1,794
RE: Intecooler continued :)
omg long posts, ill put my 2 cents in for those who dont want to read lol
intercooler without it you would get hot air, which (compared to cool air is less dense) thats means you can get less amount of air for the same amount of boost
intercooler with it cools the air, which makes it more dense, which then you can cram more into your combustion chamber, for the same boost pressure
geeze guys, wasnt that easy
intercooler without it you would get hot air, which (compared to cool air is less dense) thats means you can get less amount of air for the same amount of boost
intercooler with it cools the air, which makes it more dense, which then you can cram more into your combustion chamber, for the same boost pressure
geeze guys, wasnt that easy
05-20-2006, 07:00 PM
#9
4th Gear Member
Join Date: Feb 2006
Location:
Posts: 1,794
RE: Intecooler continued :)
wether its turbo charged or supercharged, compressed air heats up.. IC are not limited to turbo chargers.. get a supercharger and have it spin freely with the blower end open (centrifugal type of course) youll feel hot air blow on your hand, because even tho its now an open system and pressure isnt being built, apprx 3 psi is being built inside the compressor alone as it blows out on to your handand that 3psi is noticibly warm to your skin ..
now just think what hapens when you put the blower side back onto the intake pipe.. pressure can now be built, and if its intercoolerless and your running 10psi, ill tell you the air is hot enough to make you go "ow"
now just think what hapens when you put the blower side back onto the intake pipe.. pressure can now be built, and if its intercoolerless and your running 10psi, ill tell you the air is hot enough to make you go "ow"
05-20-2006, 07:04 PM
#10
I ♥ Acer
Join Date: Jun 2005
Location:
Posts: 766
RE: Intecooler continued :)
ORIGINAL: blackfoot
omg long posts, ill put my 2 cents in for those who dont want to read lol
intercooler without it you would get hot air, which (compared to cool air is less dense) thats means you can get less amount of air for the same amount of boost
intercooler with it cools the air, which makes it more dense, which then you can cram more into your combustion chamber, for the same boost pressure
geeze guys, wasnt that easy
omg long posts, ill put my 2 cents in for those who dont want to read lol
intercooler without it you would get hot air, which (compared to cool air is less dense) thats means you can get less amount of air for the same amount of boost
intercooler with it cools the air, which makes it more dense, which then you can cram more into your combustion chamber, for the same boost pressure
geeze guys, wasnt that easy